Like many viral infections, many factors including varying strains of virus, and multiple host variables affect the severity and course of the disease. Young puppies 3-6 months old are the most susceptible-younger puppies have some protection from maternal antibodies acquired through the placenta, and older dogs are both less susceptible to the virus and more likely to be immune to vaccination or mild infection. Effective vaccinations have been available since the 1960's, and I cannot find any data with specific information about mortality rates. Canine distemper does have a high mortality rate in puppies, probably much greater than 50%, and dogs that survive are likely to have severe neurological complications months or years later. However, depending on factors such as age and immune status, some dog do have mild cases, and some dogs do recover completely. These cases have the potential to convince clients and veterinarians that a variety of ineffective treatments work. It is natural for owners to bond with puppies quickly, and providing supportive care to a very sick puppy is tedious and frustrating, which leads people to look for other potential treatments for the disease.
One client this year was in just this situation, and as I mentioned above, brought my attention to Dr. Sears' "treatment" for canine distemper. I will repeat that I have no reason to think that Dr. Sears or Ed Bond are not sincere and honest in their belief that this treatment, which involves either creating serum from a donor dog or treating the infected dog directly by injecting modified-live virus Newcastle vaccine (usually used for poultry) intravenously. They also encourage vaccination, and state that the vaccine is the best way to prevent distemper. Unfortunately some of the instructions they provide on their site seem to be directed more at owners or shelter personnel than to veterinarians. They posit that the newcastle vaccine virus is better than distemper virus at inducing cytokines (a non specific term for a wide variety of proteins such as interleukins, interferons and others) and these cytokines enable or "stimulate" the dog's immune system into fighting off the distemper infection. While this idea is not impossible, there are several things about the claims on the various websites that raise red flags for me. These include; 1: claims for effectiveness with absolutely no data presented to back up those claims, 2: hints that most dogs still experience the usual complications and sequelae of the disease, 3: a lack of information about side effects or mortality from the treatment or in the dogs used as serum donors, 4: the claim on the page about Dr. Sears that he has developed treatments for a wide variety of diseases but has never published anything about these treatments, 5: finally there are several reasons to be concerned about potential problems with this treatment that are not related to it's effectiveness or lack thereof.
1; They claim that injecting the serum or vaccine early in the disease will cure distemper within 24-48 hours. However, they do not provide anything other than a few testimonials to support this claim. They say Dr. Sears has treated hundreds of dogs, but do not provide any well documented case reports. Apparently Dr. Sears first developed this treatment in 1970, and "presented" it at a veterinary conference, but was told to sit down. Since then, he has apparently kept the treatment to himself until Ed Bond started the various websites in about 2000. Dr. Sears says he does not have money to research the treatment, but he has not, as far as I can tell, even published any case reports. A case report basically only requires good records and some time to write it up. If the evidence from the case report is compelling enough, others may do the research needed to develop further evidence. Science and medicine progress by the publication and free spread of knowledge, not by keeping things secret for decades.
2; Statements they make on their site recommend continuing supportive care during and after the treatment, which is generally all we can do to try to help a dog make it through the infection anyway.
"Even if the treatment is successful, the disease has probably done damage to the lungs, stomach, eyes, pads of the feet, etc. You will need to treat these symptoms as needed."3; They claim that giving the patient or donor dogs the Newcastle vaccine creates a cytokine storm;
"The Newcastle Vaccine creates a thunderstorm of activity within the dog’s immune system. We think this unleashes a previously unknown class of cytokines — proteins that create an immune response — that can enter a cell infected with distemper and kill the virus. We don’t know how or why, but it works and it works quickly, often within 24 hours."Cytokine storms are thought to be one of the reasons certain viruses are so deadly (the 1918 flu pandemic for example). If they really are creating a cytokine storm, then at least some of the donor dogs or patient dogs should be expected to show the effects of a cytokine storm, which can include respiratory failure and death. However, they say the procedure is safe and that they have never had a donor dog die.
4; Dr. Sears claims to have developed novel treatments for several other diseases, but has never published anything about those either. Some of these diseases either have other established treatments, are preventable, or are self limiting.
"Diseases that he has developed treatments for include distemper, herpes (fading puppy syndrome), feline FUS, post-surgical cutaneous granulosum of the doxy breed, giardia, canine and feline trichomonas, babesia gibsoni and others. However, none of this has entered the veterinary literature at this time."Why have none of these wonderful treatments entered the veterinary literature. As I mentioned before, case reports are not expensive, and while scientific criticism can be harsh, that is how progress is made, if you have the evidence to back up your claims.
5; There are several reasons to be cautious with a treatment like this. Paramyxoviruses have a nasty habit of occasionally affecting different species than usual, and a search on PubMed for zoonotic paramyxoviruses
gets 19 hits, including one on the detection of antibodies to avian viruses in humans and another potentially linking Paget's disease to canine distemper virus exposure. There are also potential concerns about recombination of live-attenuated Newcastle vaccines with other viruses. While these concerns may seem slightly far fetched, they are no less plausible than the postulated treatment itself.
Finally, there is the concern that injecting a very sick animal with an attenuated vaccine could be dagerous to the individual patient. I wonder how many patients have died under this treatment protocol? they do say procrastination means death, but provide no information about how many animals have not survived the treatment, either due to it's inefficacy or to adverse effects.
Anytime someone makes claims such as the claims that are being made for this treatment, they have an obligation to keep good records of both the positive and negative outcomes. At this point there are hints that the treatment may not be as effective as it's supporters would like, but by focusing on the positive outcomes, and minimizing the negative, there is no way to tell if the treatment is effective, ineffective or just downright dangerous. This is true for this treatment as well as many CAM treatments. When some patients get better, it is easy to attribute their improvement to whatever you did, but some dog have always survived distemper.