Thursday, December 30, 2010

Dr. Palmquist continues to abuse science on HuffPo.

I wrote last summer about Dr. Richard Palmquist's first post on Huffington Post, and how his idea of science does not match science as most people understand it. He continues to rely heavily on emotional anecdotes, confuses correlation with causation, and lists a lot of scientific sounding references which usually are of poor quality or do not support his conclusions. In his most recent post, he continues the pattern he established with his first post, but this time promoting the homotoxicolgy ideas he is fond of as scientific advances.

He begins his post with a description of  an old cocker spaniel with multiple benign skin tumors that is about to have surgery to remove the masses. As in his other posts, Dr. Palmquist presents these anecdotes in such a dramatic and emotional fashion that it is difficult to tell if he is describing the case accurately, exaggerating, or just making up a good story. That said, I don't know that I have seen a 13 year old cocker spaniel that did not have multiple sebaceous adenomas. Sebaceous adenomas, cysts and other benign masses on or just under the skin are very common in older dogs, and are even more prevalent in certain breeds such as cocker spaniels. I am not sure why anyone thought it was necessary to remove all of the adenomas-as small benign tumors it is fairly common to leave them alone and simply monitor them for problems like inflammation, infection or bleeding. If benign masses like sebaceous adenomas are stable and not causing any problems, most veterinarians will not insist on removing them surgically, and sometimes they will resolve on their own. Often they will bother the animal's owner more than the animal, which is one reason to remove them, and since they are usually fairly small, superficial skin  tumors, they can often be removed fairly easily using a reversible sedative, local anesthetics, and a few days of fairly safe pain relievers, so Dr. Plamquist's representation of the surgery as quite painful, seems like an exaggeration, as well as the impression that not doing the surgery is some kind of revolutionary idea on his part.  Where He really goes off the rails however, is in his representation to the owner that the adenomas, which very likely have a genetic component to their development because of their high incidence in certain breeds, are caused by ill-defined "toxins" and should be treated with a variety of homeopathic preparations. If the adenomas really resolved on their own as Dr. Palmquist describes, it is more likely to be a result of inflammation related to the previous biopsies (described as "special testing" in the post) or simply a coincidence than due to the homeopathic remedies he provided. Some of the remedies made by Heel are low dilutions, so there is the possibility that there was some active ingredient in the treatment, but the dose was still likely to be very small. Amusingly, the one mass that did not resolve on it's own is explained away as being on an acupuncture point. Somehow the point or the tumor magically "knows" something and is trying to tell us the dog needs it there to maintain circulation to the brain and cognitive ability. There are some Chinese studies that claim to demonstrate this type of benefit, but unfortunately nearly all studies of acupuncture from china are positive, suggesting publication and other biases, which make it difficult to evaluate such studies. There has not been any research replicating these findings elsewhere. Because of this magical location on an acupuncture point, they decided to watch the tumor, which has been stable for years. As I said before, many veterinarians will do the same thing with no need to come up with magical rationalizations for it.

These ideas come from a early to mid 20th century offshoot of homeopathy called "homotoxicolgy". Hans-Heinrich Reckeweg, the inventor of homotoxiclogy, denied the germ theory of infectious disease and included vaccines and pharmaceutical treatments in the "toxins" which he thought needed to be removed from the body. Heel, the company founded by Reckeweg, has been in trouble in the past for fraudulent claims and marketing of it's products, and a review of randomized trials of Heel products by Edzard Ernst and K. Schmidt revealed serious flaws in the studies and a lack of evidence supporting their use. For a self-proclaimed "research geek", the references Dr. Palmquist supplies to support his views seem to be accepted credulously and uncritically, and perhaps with the expectation that nobody will actually check to see what the references actually say. Most of the studies are in-vitro, preliminary and published in questionable journals such as Medical Hypotheses or alternative medicine journals which are often uncritical of poor studies and biased toward promoting their particular modality. One of the references has been thoroughly discussed by Dr. Rachie and Orac, (shockingly, the 87% alcohol used as diluent for the remedies is toxic to cancer cells in vitro!) the Cochrane review provides very weak support despite being authored by homeopaths. the authors concluded; 
     "This review found preliminary data in support of the efficacy of topical calendula for prophylaxis of acute  dermatitis during radiotherapyand Traumeel S mouthwash in the treatment of chemotherapy-induced stomatitis. These trials need replicating. There is no convincingevidence for the efficacy of homeopathic medicines for other adverse effects of cancer treatments. Further research is required."
The one study of companion animals published in a more mainstream journal (Neumann S, Stolt P, Braun G, Hellmann K, Reinhart E. 2010. Effectiveness of the Homeopathic Preparation Zeel Compared with Carprofen in Dogs with Osteoarthritis. J Am Anim Hosp Assoc. Dec 16. [Epub ahead of print]) was uncontrolled, unblinded, and has other problems, including an average age difference of nearly 3 years between the two treatment groups, with the younger group recieving the homeopathic remedy. This study was also funded by Heel, the producer of the homeopathic remedy.

Finally, Dr. Palmquist describes how he thinks medicine should "work", by which he means new therapies should be developed. Unfortunately, the order of investigation he describes is somewhat backward. Plausibility should be the first test for any treatment, and his statement that homeopathic remedies have been proven to work and have understandable mechanisms flies in the face of our understanding of basic physics and chemistry, and is only accepted by true believers in homeopathy. Anecdotal evidence for effectiveness is not a reliable way to discover new treatments and is only a very preliminary way  to start to investigate a new treatment. Exceedingly implausible treatments like homeopathy are probably not worth studying further, as preliminary weakly positive results are likely to be the result of bias, coincidence and random chance. These type of preliminary positive results seem to always disappear in better designed trials of homeopathy. While I am sure Dr. Palmquist means well, he is a poster child for demonstrating how cognitive errors and wishful thinking can lead us down a path full of dead ends and useless therapies. Unfortunately, his influence as president of the AHVMA and a member of AAHA gives him an undeserved platform to promote his delusions. In this case, no harm was done to the patient, but sometimes the result is not so good.

Life and Death in the winter snow.

I noticed feathers falling past my front window this afternoon and looked outside to find this Sharp-Shinned Hawk eating a small bird in the Ponderosa Pine tree in the front yard. The temperature outside was 13 degrees Fahrenheit. A small bird needs to consume a lot of calories to survive in these temperatures.


Wednesday, December 8, 2010

Twisting facts to suit "theory". How smart people can fool themselves.

              “It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories instead of theories to suit facts.”
Sir Arthur Conan Doyle

   It often seems strange how frequently smart, well educated people seem to fall for pseudoscience. Doctors and Veterinarians are certainly no exception, and it is not unusual to see veterinarians recommending poorly evidenced treatments or even treatments with evidence against their effectiveness. People often ask how a trained medical professional can fall for such things and then promote them. In addition to regression to the mean, selection bias and other cognitive errors, we are all prone to the illusion of control. A recent paper in the British Journal of Psychology (discussion by Ben Goldacre here as the entire paper is behind a paywall) helps to demonstrate how this illusion can develop in medical professionals and suggests some ways to avoid it. Unfortunately, many veterinary school curricula and continuing education rely heavily on a fairly authoritarian presentation of information and rote memorization that do not help students to learn to evaluate claims critically and understand the evidence base behind various treatments.

  In recent comments on The SkeptVet Blog, several different people have suggested that skeptics should not criticize alternative treatments until they have tried them.This advice is given without an awareness of how easily we all make cognitive errors and how those errors can give us an illusory view of the effectiveness of our treatments. To be fair, we are all just as susceptible to this type of cognitive error no matter what type of treatment we are using, and we should always be wary of misdiagnosis or inappropriate treatment selection, situations in which these types of cognitive errors are common in both evidence based and alternative medical treatments. It underlines the importance of blinded, controlled trials, and the evaluation of the strength of the evidence supporting any treatment in  as objective a way as possible. "Trying it for yourself" is just a good way to fool yourself, and the more confident you are in your experience and ability, the more likely you are to believe that an ineffective treatment works. This new psychological paper just demonstrates the idea again in a relevant way.

Thursday, October 21, 2010

Bad Science


An excellent read, with well written descriptions of how ineffective treatments can seem to work, and how smart people can believe that they do. Recently released in the US, so pick one up if you are interested.

Thursday, October 14, 2010

Discovering a new species; what kind of evidence is good enough?

Well, the actual animal in hand is usually sufficient. Scientists are still discovering new species (unknown to science, if not to the local residents) on a regular basis. For some reason, it is biologists making these finds, not cryptozoologists, who seem to spend more time either chasing after or perpetrating hoaxes rather than finding real evidence for unknown animals. While a large primate living in North America would be an amazing discovery, the fact that no one has found any definitive evidence in the form of a body, bones, DNA, or even fossil evidence would seem to indicate that the probability of it's existence is close to zero. The real animals still being discovered are fascinating enough.
 
Photo credit; Durrell Wildlife Conservation Trust

Saturday, September 25, 2010

An Anti-vaccine Veterinarian-an interesting mix of pseudoscience, faith, and nonsense.

A particularly egregious example of an anti-vaccine veterinarian was brought to my attention recently (hat tip to Terrierman). Dr.Patricia Jordan has published online a poster she presented at the 5th annual joint North American Homeopathic Conference this year. Her personal website (titled "Mark of The Beast-hidden in plain sight-the case against vaccinations" by which she appears to mean that vaccinations are the mark of the beast) also reveals similar ideas which add up to an interesting mix of misinterpreted and misrepresented science, what appears to be the influence of evangelical style christian creationism, big-pharma and government conspiracy theories, and just plain making things up to suit her ideology. This type of ridiculous reasoning is one of the things that makes me very skeptical of information coming from alternative medicine professional organizations such as the American Holistic Veterinary Medical Association or Homeopathic associations-all to often they seem to accept ideas such as Dr. Jordan's uncritically.

From the Curriculum Vitae page on her website, it would appear that Dr. Jordan had a distinguished undergraduate and veterinary school career in the 1980's with several externships and even some type of award for epidemiology. Since the late 1990's it would seem that she has not found a variety of alternative medicine she does not like, including Reiki, homeopathy, acupuncture, traditional Chinese medicine, spinal manipulation and "pulse diagnosis". The legitimate scientific veterinary conferences and seminars she has attended in that time appear to consist mostly of vaccine related events, which she has apparently interpreted as evidence that vaccines are the cause of nearly all disease and some kind of spiritual menace. She conveniently ignores the fact that many vaccine preventable diseases in animals and humans have huge costs in mortality and morbidity by orders of magnitude over any evidence for adverse effects of vaccinations. It makes me wonder if she has ever seen a case of canine distemper, parvovirus or Rabies, or any of the other viruses we routinely prevent with vaccination.

To be fair, there has been a legitimate scientific debate over vaccination of pets over the last 10-20 years which has resulted in some significant changes in vaccination protocols for pets. All Rabies vaccines were changed to killed virus vaccines in the 1980's when it was found that the modified live virus vaccines could, in rare cases, cause rabies. In cats, this had the unintended result of causing malignant tumors in some cats (1). This can also happen in dogs, but is much more rare than it's incidence in cats, which has been reported between one in 1,000 to one in 10,000 cats. Other adverse effects of vaccination are primarily acute and delayed allergic reactions, with very little evidence that other diseases, such as autoimmune disease, other types of cancer, neurological or behavioral diseases are caused by vaccination. For a detailed analysis of these issues, visit The SkeptVet here. While vaccinations can trigger allergic reactions and on rare occasions various autoimmune diseases, this is not proof that the vaccination causes these problems. The greatly varying incidence of allergies and autoimmune disease among different breeds would suggest underlying genetic susceptibilities, and any naturally acquired infection or allergen exposure is as likely or more likely to trigger an outbreak as a vaccination is. As evidence has accumulated about the duration of immunity from vaccination, most veterinarians have switched from annual vaccination protocols to 3-4 year protocols for most vaccines, and I would not be surprised if some of these were extended even more as more evidence is accumulated for longer duration of immunity. Despite this active scientific evaluation of animal vaccination over the past decade or so, Dr. Jordan seems to have decided for ideological reasons that all vaccinations are bad.   Lets look at some of the claims she makes and compare them with the science.

This paragraph from Dr. Jordan's poster illustrates many of the distortions and errors which she makes;
Only vaccinated individuals were found to develop auto antibodies in a landmark study done at Perdue University. Auto antibodies are made with the vaccines from the viruses, from the microbial antigens, from the aluminum and mercury and other ingredients that would mutate or disrupt the pathogen. The increase of molecular mimicry increases with vaccines and these examples of pathways to increase the number of auto antibodies formed the trigger necessary to promote genetic expression of autoimmune disease. Certainly, autoimmune disease expression is one step closer to genetic disease and that handicap will transfer vertically to the next generation in many instances. The important understanding is that the adulteration of the genome came in via the injection of vaccine.
  
It is true that several scientists at Purdue have done a lot of work evaluating the efficacy and potential adverse effects of vaccination in dogs (examples of their work in references 2, 3, and 4). However, auto antibodies are antibodies which react to normal tissues in the body, and may be formed by exposure to animal protein contaminants of vaccines, and occasionally from injuries to tissues such as the lens of the eye, not normally from viral or bacterial antigens, or by exposure to the small amounts of aluminum or mercury present in some vaccines. Let's see what they have to say from reference 3;

 To date, routine vaccination of these Beagles has not caused any overt signs of clinical disease.  However, the blood of all the vaccinated dogs contains significantly elevated concentrations of antibodies directed against proteins that are present in commercial vaccines as contaminants of the production process.  None of the unvaccinated control dogs has had a similar increase in these antibodies.  These proteins are typically of bovine origin since fetal calf serum is used to grow the viruses for vaccine production.  The close similarity in structure of the bovine proteins to dog proteins results in a situation whereby the antibodies produced by the vaccinated dogs may cross-react with dog tissue proteins in a process similar to autoimmunity. Experiments in other animal species suggest that these autoantibodies might eventually cause diseases in the vaccinated animals, but these
Beagle dogs will need to be followed longer to determine if this is the case.  In addition, the pattern of individual responses of the immune system to vaccination in this study suggests a possible genetic predisposition to autoimmunity.
(this paper appears to have been published online and is no longer available at Purdue's website-this extract was taken from a breeder's website). These results are much more preliminary than Dr. Jordan or some breeders make them out to be, and while they are cause for concern and may be reason to change vaccine production methods, there is no mention of the vaccine directly causing mutations. I have not been able to find any evidence that vaccines cause "adulteration of the genome" which is transferable to the next generation. Perhaps one of the most insidious results of this type of reasoning is that some breeders use it to blame problems caused by inbreeding on vaccination instead. The Purdue paper seems to be commonly misused in this way on many breeder's and "holistic" veterinarian's websites. Unfortunately Dr. Jordan and others are taking a legitimate scientific controversy and distorting it beyond all recognition and far beyond the actual evidence. This quote from Dr. Jordan's personal website's mission statement illustrates in her own words how she has abandoned evidence and science for the ideologically based view she prefers;
It was a decade out of medical school before I clearly saw that the beliefs of modern medicine were simply beliefs and not in alignment with the innate wisdom of the body. Vaccines and drugs are at odds with the intelligence of the almighty design and getting back to the garden means getting back to the natural form and using the optimal nutrition, energetic repair and right relationship of living.
There are many more examples of distorted ideas about evolution and the immune system in Dr. Jordan's poster and website. Since she does not list any references(there are no references on the poster and the references and resources pages on her website are blank), it is difficult to discover where she gets most of her ideas. Many probably come from her own head, and others are from sources I was unable to track down.
In any case, following ideas such as these would be extraordinarily dangerous for pets and humans, indeed far more dangerous than vaccinations have ever been. For an excellent discussion of the relative risks and consequences of antivaccine movements on the human side, see Prometheus' recent post here. It is sad that Dr. Jordan seems more interested in fear mongering and selling books than rationally evaluating the evidence.

References;

June 1, 2005, Vol. 226, No. 11, Pages 1821-1842
doi: 10.2460/javma.2005.226.1821

The current understanding and management of vaccine-associated sarcomas in cats

July 1, 2007, Vol. 231, No. 1, Pages 94-100
doi: 10.2460/javma.231.1.94

Adverse events after vaccine administration in cats: 2,560 cases (2002–2005)
George E. Moore, DVM, PhD, DACVPM, DACVIM; Andrea C. DeSantis-Kerr, DVM; Lynn F. Guptill, DVM, PhD, DACVIM; Nita W. Glickman, MPH, PhD; Hugh B. Lewis, BVMS, DACVP; Lawrence T. Glickman, VMD, DrPH 

3.Effects Of Vaccination On The Endocrine And Immune Systems of Dogs,  Phase II Purdue University, November 1, 1999 
Drs. Harm HogenEsch and Larry T. Glickman 

4.J Am Vet Med Assoc. 2002 Aug 15;221(4):515-21.

Evaluation of antithyroglobulin antibodies after routine vaccination in pet and research dogs.

Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
 

Tuesday, August 24, 2010

"Heads I win, Tails You Lose"

This is an excellent article by Richard Wiseman on psi research and how studies are poorly designed, statistics are misused, and results are distorted to support psi research. Many of these problems are also common to many types of CAM research and unfortunately, sometimes other medical researh as well, so this is a useful article to keep in mind when evaluating medical claims. Basically, it illustrates many things which pseudoscience and sometimes just bad science does which should be kept in mind when critically evaluating claims.

Monday, August 9, 2010

Raw Milk; the myths and the evidence.

I wanted to draw attention to a new website dealing with the scientific evidence relating to human consumption of raw milk. There are many claims that raw milk is better than pasteurized milk, most of which are based on anecdotes and testimonials, and not on stronger evidence. On the other hand, there is a lot of evidence that bacterial contamination of raw milk can cause serious illness and even death in humans, especially in susceptible people such as very young children, the elderly, and anyone with a suppressed immune system. While some of the bacteria which commonly occurred in raw milk (bovine tuberculosis and Brucella) have been eliminated from livestock in  the United States and much of Europe, there are still several types of bacteria that can cause serious illness, especially in high risk groups. This is important because some of the claims  made for raw milk relate specifically to health claims about children which are based on poor or no evidence. Raw milk may be an especially serious risk to urban or suburban children who may have no previous exposure to these bacteria. In contrast, children raised on farms probably receive some passive transfer of immunity from their mothers, and may also be constantly exposed to similar bacteria, allowing them to develop immunity. This does not mean that farm children never experience these illnesses, but the immune resistance of children who live away from a farm environment may be lower to these livestock related bacteria.

Real Raw Milk Facts is a new website written by veterinarians, food scientists and epidemiologists which provides the evidence for claims relating to raw milk and the risks of consuming raw milk products. It has an extensive list of scientific references relating to raw milk related disease. If you or someone you know is considering giving yourself or especially children or other susceptible persons raw milk, make sure that you understand that the evidence for benefits from raw milk is poor to non-existent, and the risks of exposure to dangerous bacteria are much higher than they are with pasteurized dairy products.

Wednesday, July 28, 2010

The Rabies battle continues, in my backyard and yours.

I have posted about the new strain of rabies virus associated with bats but also capable of causing outbreaks in other species such as foxes and skunks a couple of times. There have not been many cases reported in carnivores this year, probably due to the wildlife vaccine program which they did last year. This program involves oral vaccines distributed for foxes, coyotes and raccoons, and a trap and vaccinate program for skunks (unfortunately the oral bait vaccine is not effective in skunks for some reason). The dedicated personnel of the USDA wildlife services rabies management program get the lovely job of trapping and vaccinating skunks in Northern Arizona again this summer to prevent the spread of rabies virus from bats into terrestrial animals again.
Currently they are vaccinating skunks in my neighborhood. I found a trap about 100yards away from my house today, complete with a small skunk hiding in the brush near the trap waiting for darkness before traveling away from cover again.
This skunk was very calm and sleepy during the middle of the day, waiting for nightfall to resume it's normal foraging.
 The ear tags indicate that this skunk has been vaccinated against Rabies.

This program is an interesting example of how science based veterinary medicine can improve the lives of both humans and  animals. Eliminating terrestrial rabies would reduce the risk of exposure for both wild and domestic animals and humans as well. If you have a program like this going on in your area, be sure to express your appreciation of the sometimes unpleasant and nearly always under appreciated work that these people are doing on your behalf.

Monday, July 26, 2010

A new resource for information on stem cell therapies.

 There was a very good NPR story this morning on Morning edition on both the scientific potential of stem cell therapies and the false hope and outright quackery being offered to desperate people by stem cell clinics, especially overseas in places like China. The story did an unusually good job of reporting on the current use of stem cell therapies and the unscientific, premature, and possibly even fraudulent clinics that have erupted all around the world in recent years. They also mentioned a new website started by the International Society for Stem Cell Research  that does a good job explaining the state of the science of stem cell therapy, and more importantly has a place for people to submit the names of clinics and stem cell therapy claims for evaluation by experts in the field of stem cell research. This site seems to be oriented toward human stem cell therapies, but could still be useful for veterinary information due to overlap between human and veterinary medicine. The premature and fraudulent use of stem cell therapies in human medicine is a far larger problem than it is in veterinary medicine, but these researchers may also have knowledge of veterinary applications of stem cell research. Once the initial evaluations of human clinics are done, I hope they will look into the veterinary claims as well. The site should be a valuable resource for science-based information in any case and will be worth keeping an eye on as evaluations of clinics are published.

Sunday, July 18, 2010

The Monsoon along the Mogollon Rim.

The Mogollon Rim in north central Arizona rises suddenly to an elevation of about 7-8,000 feet above sea level. This sudden elevation change means that the rim gets more snow in the winter and more rain during the summer monsoon than anywhere but the highest mountains in the state. The area was made famous to the rest of the world by General Crook's campaigns against the Apache in the 1870's, and Zane Grey's writing in the 1920's. The rim has been an important summer hunting and gathering ground for thousands of years. The combination of high altitude and the resulting increased moisture means that water and a variety of plant and animal foods are available on the highlands above the rim when the desert below is sweltering in temperatures well over 100 degrees Fahrenheit. The berries we usually pick are not quite ripe yet, but should be within a week or so, and other interesting plants and animals are active.
A view of the Mogollon Rim from it's crest.
A mountain tree-frog Hyla eximia, one of two tree-frog species in Arizona.
This is the first time I have ever seen one, and I would have missed it among the green leaves if it had not moved when we walked by.
The first edible wild mushrooms of the year.
Oyster mushrooms are fairly easy to identify, and do not really have any toxic lookalikes.
Always be cautious collecting and eating wild mushrooms-consult 2-3 references and someone with experience first.
An unsuccessful attempt to dig a red squirrel out of it's refuge.

Monday, July 5, 2010

New developments with Dr. Alson Sears' NDV treatment of Canine Distemper, and more worrying signs of quackery.

I posted about Dr. Alson Sears' treatment for canine distemper last year, and there have been some interesting developments since then that I thought should be addressed.  There is at least one new person involved who I believe genuinely cares about animals and who seems to be convinced that the treatment of canine distemper involving Newcastle disease vaccine is actually effective. Unfortunately, there is not any better evidence that the treatment is effective, despite two different groups collecting donations to support their efforts to have more dogs infected with distemper treated. Ed Bond, the journalism teacher is still promoting the treatment with his own website and a facebook group, and now someone named Jane, who has her own shelter/rescue operation and writes her own blog and a blog on the Houston Chronicle website is now collecting donations for "Project Hope" which is dedicated to producing Dr. Sear's serum using Newcastle's Disease Vaccine administered to dogs and treating distemper cases with it. While I am still convinced that everyone involved in promoting this unproven treatment means well, and that they truly believe that it works, there are some disturbing signs of "mission creep" in the diseases which they claim to be able to treat, and the attempts to prove the treatment effective look inadequate to provide the kind of proof which they would like. At this time, they are selling DVD's and taking donations to provide what is at best an unproven and experimental treatment, while presenting it as something that is a proven treatment. This raises some serious ethical and legal concerns as most of the dogs involved are coming from shelters, and in some jurisdictions it is not legal to experiment on shelter animals, and spending money on an unproven and possibly risky treatment may not be the most effective use of limited funds.

To review my last post, canine distemper is a viral disease that affects domestic and wild canines and some other wild species such as raccoons and mustelids and large cats such as lions and tigers (cats in the genus Felis-domestic cats, and small wild cats also including american mountain lions are not susceptible to canine distemper). The vaccine is very effective, and despite some problems with effectiveness about 20 years ago (1, 2, 3), canine distemper is very rare in vaccinated, well cared for dogs and puppies. It can be a serious problem in large populations of young, unvaccinated dogs, such as shelter populations. There seems to be an ongoing outbreak in shelters in the area in which I live, and there are apparently similar problems in other areas as well, which may be one reason people are looking for treatment options right now. The course of the disease in an infected dog varies depending on a variety of factors depending on the dog's age, immune/vaccine status, and the strain of virus causing the infection. Young puppies are most susceptible, especially during the period when their maternal antibodies are declining but before they have time to develop their own immune response from vaccination. The highest risk period is from 6-16 weeeks, but unvaccinated dogs can be infected at any age. Older dogs tend to have somewhat less severe infections and a higher survival rate. Once dogs do develop immunity, it is long lasting, 3-4 years at least (1, 2, 3). Severely infected dogs are susceptible to secondary, fatal infections such as bacterial pneumonia, and some dogs develop neurological complications that can cause seizures, paralysis and death. Sometimes these problems can occur months or even years after apparent recovery from the infection, and are caused by damage the immune system does in the nervous system while trying to get rid of the virus. It is difficult to predict when or if a dog with a mild or moderate case of distemper will develop neurologic symptoms.

Diagnosing distemper definitively can be more difficult than we would like. Indirect tests such as looking for distinctive inclusion bodies in cells collected from various locations are good, and PCR testing for viral antigen is better, but the standard PCR test does not distinguish between the modified vaccine virus and the wild strains, and it is unknown how often the vaccine virus causes inclusion bodies in cells. This means that vaccination can cause a positive test result for up to three weeks after vaccination. I don't doubt that most of the dogs being treated by these well-meaning people do have distemper, but it is certainly possible that some of the dogs who recover quickly have other types of infections and test positive because of vaccination. Most shelters vaccinate puppies as soon as they enter the shelter in an attempt to avoid problems, so many  of these puppies may have both vaccine and wild virus in their systems at the same time. Other infections like bacterial respiratory infections, canine influenza, and other viruses can all cause similar symptoms. Symptoms consistent with distemper and positive tests make it very likely that these dogs do have distemper, but specialized viral testing would be required to definitively prove that the dogs who recover did in fact have distemper and that the treatment actually killed the virus as Dr. Sears claims. This type of testing is normally only done in some virology research labs and at places like the CDC, where they analyze new strains of influenza and serious, unknown outbreaks of disease. Specialized immunology labs would also be required to confirm that the newcastle disease vaccine is having the effect Dr. Sears claims it has, which is stimulating a strong immune reaction in the donor dogs, such that a few milliliters of serum is enough to kill all the virus in an infected puppy.

There seem to be signs that the proponents of the treatment are using some selection bias when reporting the results of the treatment, and overstating the number of dogs which survive. I will provide some quotes from their sites that seem to illustrate this. Project Hope is named after a puppy that did not survive the treatment, and there seem to be quite a few similar cases when I searched through the discussion pages of the facebook group;
The serum treatment for distemper is nearly 100 percent--I don't know of any cases that failed but in medicine, there is never 100 percent of anything.
(May 5th, 2010 Jane's blog)
This is almost 6 months after "Hope" died despite treatment, and after other failures;
 SaveDogs FromDistemper  Sadly all 5 Croatian puppies died, but the adult with neurologic symptoms has recovered. They are calling it a miracle.
(December 19, 2009 at 7:17am Facebook Group)
There are others as well when you scroll through the discussion pages.

Since distemper is such a serious disease, dogs who recover often have an extended recovery. Despite claims that the Newcastles treatment is so effective, they have many cases where the dogs take a long time to recover. This (and their failures) is blamed on the secondary infections, or the treatment coming "too late", which is unfortunately something which happens all too often in defense of many unproven treatments.

She is a Project Hope serum puppy.  Three weeks ago, after being diagnosed with distemper at her vet, Brindy received Dr. Sears' NDV-induced serum, a treatment for distemper.  She had an advanced case of distemper--green crusty nose, green crusty eyes, pneumonia...and she had a skin condition of some sort. The distemper was dead in 24 hours according to Dr. Sears.  The other issues have yet to be cured.
(Feb. 15, 2010 Jane's blog)
Skin problems can be caused by distemper as well.

 It will take some weeks or even months (4 weeks to 4 months is what Dr. Sears tells me is a good rule of thumb) for the damage that was done to repair itself.                                    (March 19, 2010 Jane's blog)
They are also starting to make claims that the treatment works for a wide variety or other dieseases, with apparently no evidence whatsoever. Occasionally they contradict themselves, as Dr. Sears says at one point in a video clip that the serum does nothing against parvovirus, but claims otherwise elsewhere.
Dr. Sears is now including the NDV-induced serum in protocols to treat not only canine distemper, but parvo and herpes as well as several other diseases.  The first puppy testing positive with parvo had serum and within just several days, her fever went down and her recovery seems to be rapid.  This is making me think some.

First of all, having the serum is like having a life-insurance policy for our dogs/puppies.  As long as we act fast enough, and don't waste weeks with other vets getting ineffective treatments, the serum is very close to miraculous.  If I didn't know that serum was in Houston, I would be very nervous about the outbreaks of distemper and parvo.
(April 3, 2010 Jane's blog)
What is fascinating, is that this same disease model--what Dr. Sears' is using to treat distemper--can be used to eliminate human diseases like MS and maybe even cancer.  Yes, this is huge--and we have to do a little bit each day.  What we are learning and teaching, thanks to Dr. Alson Sears, will make a difference in this world.
(Feb 15, 2010 Jane's blog)
 Those are pretty remarkable claims, and I am sure Jane really hopes and believes they are true, but it does not seem to bode well for the scientific attitude toward the treatment they are promoting.
They seem to want to prove that the treatment is effective, which is a good thing, but they don't seem to have anyone with any scientific training working on it. Their claims of ties to Texas A&M seem to be limited to sending their diagnostic tests to the lab there. At this point there is no indication of involvement of the veterinary school there in researching this treatment.
This will be a publicly-funded project (donation-sponsored) and the serum will then be free to those who need it--and agree to participate in the screenings for distemper which are being sent to, and tested by, Texas A & M. It is our intention to get a peer-review article for vets all over to learn from what we are doing.  How often do we get a chance in our lives to do something that can change the world?

(February 28, 2010 Jane's blog)
 In conclusion, the evidence of their own websites, and the fact that they seem to be using the donations they receive honestly, indicates that Ed Bond, Jane, and others involved in this are honestly trying to help sick animals. Unfortunately, after 40 years of using this treatment, Dr. Sears still has nothing more than anecdote and testimonial to prove that the treatment works. While he has managed to convince some well meaning laypeople, the evidence is still inadequate to non-existent, and of all the people involved in this, he is the one who should understand this. Apparently he does not. If this treatment is ineffective, the effort and money they are spending could be much better used elsewhere. I would be happy to be wrong about this, but so far they have not presented anything to convince me that I am. If they really want to show that the treatment is effective, they need to establish that the treated dogs all actually had wild strains of distemper, and their tests are not being interfered with by vaccine strains of virus. Ideally, they could run a blinded, controlled trial to be sure that treated dogs survive distemper at a higher rate than dogs given standard, supportive care. They also need to keep meticulous and honest records of both positive and negative outcomes. It might be difficult to convince everyone involved to do this, since the primary promoters of the treatment already seem convinced that it works, and may be reluctant to not treat some dogs in a trial. However, if they really want to know if this treatment is effective, and produce evidence that other veterinarians would accept, that is what they need to do, even if the results are disappointing in the end. It is possible that the treatment is a false hope, which would be worse than the small hope available now to owners of severely infected puppies. If the treatment is ineffective, as I suspect it may be, then they can concentrate on helping dogs in more effective ways.

Addendum; 7/28/10;
For those who might be interested in another, science-based resource on shelter medicine and issues such as distemper problems in shelter animals, the UC Davis Koret shelter medicine program has an excellent website with a page on canine distemper. Related to the outbreak local shelters are experiencing, the use of the relatively new recombinant distemper vaccine produced by Merial can be useful as it does not cause false positive PCR tests. The use of this vaccine by those trying to demonstrate efficacy of Dr. Sears' treatment would be one thing that would help to increase the validity or their results.

Friday, July 2, 2010

Flagstaff Summer Film Festival

For anyone in Northern Arizona, or anyone who would like to spend a little time in the beautiful summer weather of Flagstaff, Arizona this August, here is an idea; The first annual Flagstaff (Summer) Film Festival.
The founder has chosen a lot of interesting independent films (partial list available here) many of which have themes relating to science or skepticism, including alternative medicine, border and immigration issues, and other topics.

Hope to see you here!

Wednesday, June 9, 2010

Veterinary Nonsense on the Huffington Post.

The Huffington Post is home to some of the most ridiculous and idiotic writing on human alternative medicine, and now, not to be left out, the have a veterinarian writing on "integrative" veterinary medicine. A recent post by Dr. Richard Palmquist brings veterinary integrative medicine into the world of woo that is the medical and lifestyle pages of the Huffington Post.

He begins with a statement of his scientific background;
My parents were science-based people: my mother was a dental educator and my father was a microbiologist. Many of my friends were children of members of the medical community. These people were my heroes and not one of them did "crazy, voodoo crap like acupuncture, homeopathy, herbs or reiki." These people did "modern medicine," which came from science and used the best of our knowledge to help people. I was, and still am a science guy.
Apparently he forgot to pay attention to his heroes, and in science class as well, because he proceeds to interpret anecdotes, testimonials and possibly outright fraud as scientific proof that various alternative medicine techniques actually work. He also discusses bias in a twisted way. It is true that prejudices can lead to premature judgments, but it does not mean we should accept anything based on the kind of evidence he presents in his article. being open minded is a good thing, being so open minded that you stop thinking critically, or even stop thinking at all is just as bad as any other bias that can affect our thinking. He goes on to present several anecdotes to prove his point, but to anyone who does utilize critical thinking, the flaws in these stories are fairly obvious.

The first anecdote is about a discussion he had with an alternative practitioner;
I said, "I understand you cure cancer." I knew this question would expose him for the fraud I knew him to be. He responded, "No, absolutely not. We don't cure cancer. Frankly we don't even treat cancer. What we do is support individual patients' immune systems and sometimes remarkable things happen."
This is pretty remarkable; the veterinarian admitted that he did not treat cancer, but then makes the fairly meaningless claim, common to many evidence-free treatments, of "supporting the immune system". Mark Crislip has an excellent post about supporting or boosting the immune system here .
He then proceeds to discuss cases where he thinks cancer was cured by alternative methods.
Then he presented a case complete with documentation from the top referral small animal hospital in New York. This case was a cat with a massive brain tumor diagnosed with state of the art brain imaging and found to be too severe for treatment. The cat was blind and semi-comatose on presentation to his office. After receiving dietary therapy the cat regained its sight and later had new x-rays taken only to reveal the tumor was 50 percent smaller. I had never seen anything like that before.
Top hospital or not, Dr. Palmquist knows that  an image, no matter how high-tech, of a mass is not a diagnosis of a tumor. It is a picture of something which may be a tumor, an infection, or even an artifact that only looks like a mass. Either he is leaving out many details (was the mass biopsied, was the cat treated with any other evidence-based treatments, etc.) or he is not asking the scientific questions he should be asking.
The next anecdote is another cat with a tumor;
On Monday I went to his clinic to observe him work. The first case was a terrible oral tumor that was recovering after receiving cryosurgery -- freezing the tumor to kill it. I had not seen this type of surgery for this kind of disease before and was amazed at how well the cat was doing. I also noticed the intensely honest communication and loving connection he had with both the people and then cat. My heart melted a bit.
This is another common tactic of alternative practitioners; co-opting  science based treatments and calling then alternative. Cryosurgery has been used to treat many different types of tumors and other lesions for many years. It may be true that Dr.Palmquist had not seen it used to treat oral tumors, but it really should not have been such a surprise. Cryosurgery was commonly used for many years before Dr. Plamquist's epiphany. Honest (debatable) and loving communication is also not limited to alternative practitioners. The next case also should raise some red flags, but apparently by this time Dr. Palmquist was so ready to believe anything that he fainted;
The next case was a paralyzed German shepherd dog which was treated by top specialists. The dog was carried in on a stretcher and a neurological exam showed the dog to be
non-functional. I knew after such a long time that euthanasia or hopeless surgery was the only option, but the "likable quack" began applying acupuncture needles to the dog. The dog lay there happily, and then the needles were removed at which point the patient simply got up and walked over to the owners.
Extraordinary claims require extraordinary evidence. Either Dr. Palmquist was cruelly played, or he is again using weasel words to imply more that what actually happened. If the dog was really non-functional and was "cured" so quickly using acupucture, that really would have been remarkable. Again, what does "non-functional" really mean? The story sounds amazing, but many questions need to be answered before we accept the claims made here.

Since Dr. Plamquist's conversion to integrative medicine, he has apparently published many case reports, which are really just formalized anecdotes, and are not scientific proof of much of anything, and has written a textbook on integrating alternative medicine into veterinary practice. He is apparently a proponent of the pseudoscience of homotoxicology, and is the president elect of the American Holistic Veterinary Medical Association. The kind of fuzzy thinking Dr. Palmquist has demonstrated in his post does not inspire confidence in the scientific rigor of his association.

Addendum; Steve Novella has an excellent post today demonstrating the harm that can come from honest, caring and well-meaning quackery.



 

Monday, June 7, 2010

Battlefield Ridge-a microcosm of Arizona nature and history

Battlefield Ridge extends north from the Mogollon Rim for about 8 miles, and ends between East Clear Creek and Bear Canyon, one of many canyons in the East Clear Creek watershed. The ridge is named for the Battle of Big Dry Wash, which happened on July 17th, 1882, and was the last battle between members of the Apache tribal groups and the U.S. Army on Arizona soil. (Most online accounts of the battle appear to repeat errors in the timing and sequence of events of the battle-the most accurate and well-referenced description is in Dan Thrapp's book; Al Sieber, Chief of Scouts which is unfortunately out of print, but is available in many libraries.) One Cavalry trooper was killed, one apache scout was killed, possibly by friendly fire, and approximately 20 "renegade" apaches were killed in the battle.
The Canyon was later dammed, forming Blue Ridge Reservoir, which serves as a water source for the mines in Globe. Ironically, exploitation of mineral deposits in places like Globe and Jerome were one of the major reasons that the Apache were being forced onto reservations and off their traditional hunting, farming, and raiding lands in the 1870's and 1880's. 

In the last century this area has been grazed, logged, and natural fires have been suppressed, resulting in a denser forest of smaller trees instead of the open, park like pine forest that covered most of the area in the 1880's. In spite of this many of the rugged canyons in the area are in fairly pristine condition, and still have most of their original flora and fauna. 

The pictures below are from the area where the battle occurred, and illustrate the traces of the battle still remaining, and the natural beauty that persists in the area to this day. (click for full sized versions)
The front side of the monument.
The back side of the monument, listing the troopers and Apache scouts present.
The only grave at the battlefield is Pvt. Joseph McLernon's.  The Apaches who died in the battle were not buried, and were left where they fell. There is no record of what happened to the Scout who was killed.
The lower end of the ridge where the Apaches made their stand now lies under the waters of Blue Ridge Reservoir, which is often this green color due to algal blooms.
The view across the side canyon. The initial army positions were here, and the Apache  group was on the ridge that is now barely visible through the trees.
This columbine, Aquilegia desertorum grows in the limestone crevices and ledges of the area

 A small bird bolted from under the rock just under this fence as I approached.
The nest, eggs, and first hatchling are hidden underneath.

Crackerbox canyon, about a mile southwest of the battlefield is named because of the empty hardtack boxes the army left here when they camped after the battle.
A cow elk or wapiti grazing on the lush growth of the creek bottom.
At least one bear has been foraging on the early growth as well.
A dead pine and a red-tailed hawk are the only sentinels now.
The bears may soon have wild strawberries to eat.

Sunday, May 30, 2010

Acupuncture still does not work very well.

As Harriet Hall, the SkepDoc likes to say,
Studies have shown that acupuncture releases natural opioid pain relievers in the brain: endorphins. Veterinarians have pointed out that loading a horse into a trailer or throwing a stick for a dog also releases endorphins. Probably hitting yourself on the thumb with a hammer would release endorphins too, and it would take your mind off your headache.

Ed Yong has an excellent post about the latest science relating to acupuncture. While there is a physiological response locally and in the central nervous system when the skin is punctured or stimulate with needles, there is still very little evidence that these effects have any positive effect on the progression of any disease. It is troublesome that acupuncture is still being promoted by veterinarians as an effective form of pain relief for everything from surgery to arthritis. Since our animal companions cannot really tell us if they want or enjoy acupuncture, we should be very cautious with dramatic but probably ineffective interventions like acupuncture
that may have more effect on the psyche of the owner than on the patient. The acupuncture archive at science-based medicine is also well worth a read if you have not already.

Thursday, May 20, 2010

The sad case of Macho B

 AZ Game and Fish
This story has received quite a bit of attention in Arizona over the last year or two, (here, here, here and here are some examples in chronological order, also here) but may not be that well known outside Arizona. There is also a veterinary issue I would like to address that has not really been mentioned yet but that relates to this case and potentially many others. There are also some political issues that relate to large wildlife migration and border issues (fences, patrols, and other human activity), but may relate to the motivations of some of those involved. Political resistance to consideration of endangered species use of borderlands and impacts of things such as security fences on endangered species may have contributed to bypassing federal regulations in this case.

In summary, Macho B, an older adult male Jaguar was known to be living in an area of southern Arizona, and was "inadvertently" trapped Feb. 18th, 2009, and collared as part of an ongoing study of bears and mountain lions. 12 days later data from the collar showed that Macho B was not moving as much as he should be, and he was recaptured and taken to the Phoenix Zoo for evaluation. Blood tests done at that time suggested kidney failure (elevated BUN and Creatinine) and the Jaguar was euthanitzed that day.  Pathology results from necropsy indicated that he may have been suffering from fairly severe dehydration rather than renal failure, and the decision to euthanize may have been precipitous and premature. Later investigations showed that the initial capture was not accidental, as several people knew that female jaguar scat had been placed at several snares to attract Macho B. This was done without the proper permits from or knowledge of federal or state wildlife agencies. Since then, one state game and fish officer has been fired, last week Emil McCain, the biologist from the Borderlands Jaguar Detection Project plead guilty to intentionally trapping the Jaguar in violation of the Endangered Species Act, and charges have been filed against another technician. It also appears that Emil McCain has been involved in several other capture related jaguar deaths in Mexico and Central America, which raises questions as to his competence in anesthetizing big cats.

The veterinary related issue I would like to address is the way many biologists and some veterinarians are trained to immobilize wild animals, and a problem which seems to be more severe, if not unique to the United States and/or the Americas, which is the lack of utilization of veterinarians when wildlife is anesthetized, and possibly a general lack of cooperation between wildlife biologists and veterinarians. While practices vary from state to state (some state wildlife agencies have veterinarians on staff while others do not, and someone working on a research project may work for a university, or various state or federal agencies that have varying policies and availability of personnel) it seems to be very common for wild animals to be anesthetized without direct veterinary supervision by people of varying training, experience and competence. Anesthesia always carries a risk, and anesthetizing a wild animal where exact weight and health status are unknown increases the risk of adverse effects. Sometimes this risk is justifiable-for example, wildlife may wander densely populated areas where they could pose a danger to people or are in danger themselves, and game wardens may need to immobilize an animal and move it in a hurry. On the other hand, planned captures for scientific studies or preplanned management activities do not justify the same level of risk to the animals. In Macho B's case, the people involved were already ignoring regulations and will pay the price, but there are fairly frequent cases of animals dying  during immobilization. While "bad reactions" can happen, true allergic or other adverse reactions to anesthetic drugs are actually fairly rare, and saying an animal had a bad reaction may be due to human error such as an error in dose, or failure to recognize common problems such as low blood pressure, respiratory arrest, dehydration, and hyper or hypothermia. While a biologist is certainly capable of learning and practicing wildlife anesthesia, and veterinarians certainly can make the same mistakes, calculating doses and recognizing and dealing with complications benefit from both double checking and practice. Training programs for animal control, wildlife managers and biologists are often very short, and may not involve any supervised practical experience after the training session. In contrast, veterinary students spend many more hours learning relevant physiology and pharmacology, usually a couple of weeks of classroom instruction specifically relating to anesthesia, and usually several weeks at least of supervised practice on living, client owned animals in veterinary teaching hospitals. Veterinary anesthesiologists spend another 3-4 years to become board certified specialists. While a weekend course might be acceptable for animal control officers and game wardens who are only going to use chemical immobilization as a last resort in emergency-type situations, more training and some level of competence should be expected when animals are immobilized or anesthetized for less urgent reasons.

The other aspect of this topic that may relate to attitudes and problems in cooperation is the relationship between basic scientists (wildlife biologists, etc) and veterinarians at some universities seems to be slightly strained. While I was in veterinary school, there seemed to be an attitude that anyone with only a PhD was not qualified to teach veterinary students anything, and conversely veterinary instructors did not want to teach students outside the veterinary program. I have also seen biologists at other universities who seemed not to recognize or even resent the contributions veterinarians could make to their research. I have no idea how widespread this type of attitude is, but I suspect it may contribute to problems with immobilizing and anesthetizing wildlife. In Macho B's case, the initial capture was unfortunately carried out illegally and inappropriately.  It lead to a series of events that probably also included veterinary errors that resulted in the animal's premature death. Perhaps better cooperation between veterinarians and wildlife biologists could help to prevent unfortunate outcomes in the future.

      

Sunday, May 16, 2010

Signs of Spring in the mountains.

We had a little snow last week, but it is actually warming up enough for the plants and wildlife to start coming alive again. Here are a few pictures of harbingers of spring in the mountain west.

The hummingbirds show up as soon as there are few flowers (currants and gooseberries this time of year). Amazing that they survive the subfreezing nighttime temperatures we are still experiencing at night.

Bullock's Orioles are another visitor to the hummingbird feeders, and nest in the neighborhood.
Canyon tree frogs breeding in temporary pools.
Canyon tree frog habitat.
The Elk are shedding last year's antlers in preparation for growing a new set.

Saturday, April 24, 2010

Snakebite Fact and Fiction

With spring in the northern hemisphere, the warming weather brings the rattlesnakes out of hibernation. According to Arizona poison control, they have received 11 calls this April for Rattlesnake bites, four of which were dogs. I thought it might be an appropriate time to discuss snakebite fact and fiction, especially relating to first aid and animal treatments which might be found on the internet. Venomous snakebite is a fairly common occurrence around the world, and often happens in remote, inconvenient locations. This has resulted in the development of many first aid techniques and remedies that may be ineffective or dangerous. In addition, the sporadic, variable, and serious nature of snakebite makes controlled studies of even science-based treatments difficult. I will attempt to review the basic science of envenomation and what first aid and preventative treatments may be reasonable, which are not, and what treatments are effective and reasonably science-based.


Thursday, April 15, 2010

BCA drops case against Simon Singh

The BCA has finally realized how disastrous continuing their libel suit against Simon Singh is, and had dropped it. Simon will probably try to recover his costs, which have been substantial, but this is very good news for Simon and for the cause of libel reform in England.

 Details here and here.

edit; and this excellent post at Quackometer.

Monday, April 12, 2010

The appeal to antiquity-a traditional fallacy.

"The older a treatment the more respect it was given. The Greek historian Dordorus, who visited Egypt in the First century BC, wrote that the doctor who followed a text exactly would not be blamed if the patient died, but if he disregarded it and the patient suffered he could even be sentenced to death."
source ;Charles Freeman, Egypt, Greece and Rome, Civilizations of the Ancient Mediterranean, second edition,  2004, Oxford University Press, pp. 86.

One of the first things we learn as children is to listen to our parents and other older relatives. This is a good thing for a young child, who cannot yet understand which actions may be safe and which may be dangerous, but in the practice of medicine and science can stifle advancement and new knowledge. This is a problem with the apprenticeship/rote memorization model of veterinary medical education, but is an even greater problem in the promotion and use of many CAM treatments. While traditional medical practices are interesting, and sometimes even manage to hit upon effective treatments, they are invariably bound to pre-scientific notions which often have little relation to the actual causes of disease. The lack of real understanding of most diseases that was common to all cultures until recently led to various philosophical models of health and disease that often involve some type of vitalism-treatments are designed to bring some vital force or energy back into balance. Often this involved using plants, animal parts, or other substances which look like parts of the body or the elements of the vital force which need to be changed, or draining blood or other body fluids to adjust these perceived balances. Some of these treatments were harmful (bleeding, treatments involving heavy metals and other toxic substances, etc), some were harmless but ineffective, and a few were effective just by chance.
As I discussed here, ineffective treatments may be more likely to spread in a population than effective treatments.

Promoters of various forms of traditional alternative treatments often make the claim that the treatments they use are ancient when their relationship to actual ancient practices may be dubious.  Another oft-heard claim when traditional practices are criticized is that such criticism is prejudiced and racist.  This accusation relates to post-modernist beliefs that there are many, equally valid "ways of knowing".  While this approach has some value in the humanities, it does not provide much value when trying to answer a scientific question such as whether a medical treatment is effective or not.  Claims of racism or prejudice also minimize the contributions of scientists in varying cultures who may be studying traditional treatments such as herbal remedies for safety and effectiveness, or to discover and develop new compounds that may be useful drugs.  Since so many traditional treatments are likely to be minimally effective, ineffective, or even dangerous, it is reasonable to demand strong evidence of effectiveness before adopting them, no matter which culture the remedy comes from.  Equal opportunity skepticism is not racism, it is what is required to evaluate any traditional treatment.
Some traditional treatments such as bleeding, or treatments involving "magic" or the manipulation of unmeasurable energies, may be useless at best and actively dangerous at worst. Others, such as the use of Milk Thistle extracts as a liver tonic, have demonstrated some evidence of efficacy for some of it's traditional uses.

The appeal to antiquity is as old as antiquity itself, but should not be used to stifle critical evaluation of ideas.

Saturday, April 10, 2010

World Homeopathy Awareness Week

Does homeopathy work?


No.  there is nothing but water or sugar in most homeopathic remedies. It is, however, one or the most elaborate and imaginative placebos around. Save your money and don't buy the "magic" water or sugar pills.







Any questions?

Monday, March 8, 2010

More ovaries...

In a recent post I discussed a paper that claimed to show that dogs lived longer if they kept their ovaries, despite a lot of evidence to the contrary. This article got an inordinate amount of attention in the secondary literature and the blogosphere, most of it quite uncritical. With this kind of observational study, it is easy to analyze the data in a way that will give a positive result, or even to design the study in such a way that a positive result is nearly guaranteed, as discussed here, and here.

In the most recent issue of JAVMA, there is a paper that provides an interesting counterpoint to
the earlier paper. This paper discussed dogs (and two cats) that had residual ovarian tissue left after spay surgeries. Most of these animals had ovarian tissue left in the normal anatomical position for ovaries to be, indicating that failure to identify and remove the entire ovary at the time of surgery is much more common than ectopic ovarian tissue is (I have seen one cat in 20 years that had one normal ovary and no identifiable grossly visible tissue on the other side, but had a couple of weak heat cycles after surgery, then nothing). So the vast majority of these cases can be blamed on careless surgical technique, not exceedingly rare anatomic anomalies. It was also interesting that surgical experience was not a factor, again indicating that complacency and sloppiness was to blame rather than inexperienced surgeons.

This paper had a limited number of cases (19 dogs and 2 cats), so I don't want to make too much of it, but it was interesting that this small paper supported other findings that removing ovaries can prevent certain types of cancer and infections in dogs. In addition to the expected signs of estrus (which are usually not something most pet owners want to deal with) there were five ovarian tumors, seven enlarged uterine remnants, one vaginal mass and two mammary masses. On histology and culture, there were five cases of ovarian cancer, eight cases of cystic endometrial hyperplasia, and one uterine stump pyometra. It is interesting to note that this rate of ovarian tumors is much higher than that reported for sexually intact female dogs (23.8% vs 6.8%). This may be an artifact of the small sample size, but it could indicate that leaving ovaries instead of removing them during a spay could significantly increase the risk of ovarian cancer in dogs. All of this supports other evidence that early removal of the ovaries and uterus can prevent several serious types of cancer in animals and can also prevent serious infections of the uterus (pyometra).

It will be interesting to see if some of the blogs and veterinary newsletters that responded so enthusiastically to  the ovaries and longevity paper also give attention to this new paper in JAVMA. I suspect that they won't, as this paper is not really very surprising, but it does relate (and contradict) to the paper about rottweilers they were so excited about a month or two ago.

Monday, February 22, 2010

Another version of the naturalistic fallacy in the quest for longevity.

 photo credit; national park service
It is not unusual for promoters of raw diets such as BARF and "natural" diets like the evolution diet to claim that wild animals are much longer lived than domestic animals, especially when they are fed commercial dry food. The culprits in kibble are variously claimed to be "diseased" animals, grains, or various preservatives or unnamed "toxins". Similar claims for longevity in wild animals in their natural habitats are often made by promoters of various types of "natural" medicine such as herbal and homeopathic remedies.  These claims have always struck me as rather silly, so I thought it might be interesting to look at some longevity data for different species in the wild and in captivity, what they are fed in captivity, and how their longevity compares to closely related domestic animals. It might also be interesting to consider how humans and especially dogs have evolved together and how cooking and/or processing food has influenced that evolution.

It is sometimes difficult to evaluate the longevity of animals in the wild, but we do have excellent records of wild wolves in Yellowstone National Park since their reintroduction in 1995. The Yellowstone wolves have been closely monitored and studied for 15 years now, and we have data on hundreds of yellowstone wolves.
The 2008 Annual Report of the Yellowstone Wolf Project lists all known cases of mortality and the ages at mortality and the oldest surviving wolves in Yellowstone. Pup mortality has ranged from 0 to 71%, but seems to average about 50%. Periodic outbreaks of canine distemper virus seem to be responsible for years with higher pup mortality. For wolves that survive to adulthood, adults are considered "old" at greater then 5 years. At the time the 2008 report was written, wolf # 192M of the Belcher Pack was nearing 12 years of age and was the oldest known Yellowstone wolf. There were also at least two other notably old wolves alive at the time that were 11 years old. The average lifespan of a Yellow stone wolf is about 4 years. Longevity records for wolves in captivity indicate that wolves in captivity can live up to 20 years, and the oldest record in the wild is 16 years. Wild wolves die of intraspecific aggression (killed in conflict with other wolves), injuries, disease, and malnutrition. Wolves in captivity (and domestic dogs) do not tend to die of the same things-they live long enough to suffer from the diseases of old age-degenerative joint disease, cancer, etc. Wild wolves (with the exception of some endangered subspecies such as the Mexican wolf and the Red wolf) may have more genetic diversity than most domestic dogs as well, which may reduce the incidence of certain types of cancer in wolves compared to some inbred breeds of dogs independent of diet.

Since wolves in captivity live longer than wild wolves (and possibly longer than comparably sized domestic dogs) , what is the recommended diet for captive wolves? The husbandry chapters of the Nutrition Advisory Group of the American Zoo and Aquarium Association seem to recommend dry, commercial dog food as the primary source of food for captive wolves. (here, here, and here). There is also some evidence that the dental hygiene of captive wolves is better when fed commercial dry dog food then when fed a raw meat diet supplemented with bone meal and vitamin and mineral supplements. These recommendations indicate that professional zoologists and zoo veterinarians find commercial diets superior to raw meat diets for several reasons. Bones and whole prey may be given for behavioral enrichment,  or to help transition wolves to predation in reintroduction projects, but ordinary dog food is perfectly adequate to maintain wolves in captivity and avoids problems associated with nutritional imbalances, bacterial contamination and spoilage.

The situation in cats is similar, although records for longevity for small cats (genus Felis) in the wild appear to be similar to the records for captivity. This may be because small cats tend to eat small prey that is not as likely to injure the predator and are not as subject to attack by neighboring cats . Average lifespans of cats in the wild are probably much lower than domestic cats due to disease, injury and starvation, despite the potential for small wild cats to live as long as their captive counterparts. Zoo standards for keeping small felines also indicate that commercial dry cat food is the preferred maintenance food in zoos, with whole prey reserved for behavioral enrichment purposes.

Finally, I would also like to address the idea that raw food is better because humans evolved eating raw food. While this is obviously true to a point,there are recent discoveries in Africa indicating use of controlled fire as early as 2 million years ago and the hypothesis that cooking made more types of food available and digestible to early human species and drastically influenced human social structure, reproduction and body size. As early humans (Homo erectus, neandertalensis and sapiens) spread out of Africa, their ability to do so and their success depended on cooking and the use of fire. It appears that dogs were domesticated much later,  separating form wolves 15-30 thousand years ago. Part of this evolution probably involved wolves or early dogs scavenging waste and food scraps from trash heaps. The separation of dogs from wolves also seems to be related to the advent of agriculture, which means food surpluses in the form of grain and possibly root vegetables which need to be cooked or otherwise processed for digestion by humans and dogs. Cooked food may well have been important to both human and canine evolution and may have a lot to do with why we are human and dogs are not wolves in the first place.

The science behind human and animal nutrition, and the increasing knowledge of how cooking has influenced human evolution, first with cooking of wild foods, and later with the development of agriculture is fascinating. It stands in stark contrast to the vitalism and pseudoscience produced by the raw food supporters. Animal lifespans in the wild are generally much shorter than those of domestic or captive animals. While wild animals tend to die of injury, malnutrition or infectious disease before they get a chance to get cancer, there is no evidence that good quality commercial diets or cooked food cause disease in pets. The varying incidence of various cancers in different breeds would indicate again that many of the diseases which raw diets are supposed to prevent have a strong genetic component. Changes in kennel club breeding practices eliminating the severe inbreeding present in so many breeds is likely to benefit pet health more than a raw diet or a pseudoscientific "evolution diet" ever will. Claims that wild relatives of domestic animals live longer than the domesticated species do are demonstrably false, and the idea that raw food or some other type of "evolution" diet will extend lifespan appear groundless.