Tucson, Arizona | Published: 07.29.2007
WASHINGTON — Despite warnings that America’s dogs are being vaccinated too much and too often, most veterinarians continue the practice as a way to keep clients coming in the door, according to a leading animal immunologist.
Vaccines for rabies and three other major canine diseases — distemper, canine adenovirus-2 and canine parvovirus — should be given no more often than once every three years, said Ronald Schultz, a veterinary immunologist at the University of Wisconsin-Madison.
“Unfortunately, most veterinarians recommend annual revaccinations for these core diseases,” said Schultz, “and many of them are using the procedures as what I call ‘practice management tools’ — to keep clients coming in on an annual basis.”
He said many vets send annual vaccination reminder postcards because they know that when the animal is brought in for shots, they can give it an important physical examination.
“The dogs ought to be coming in for the examinations, not shots,” said Schultz.
And since all vaccinations are potentially harmful, it makes no sense to expose an animal to that risk when it already is immune, he said.
“Some vets argue that it’s better to be safe than sorry, but if you turn that around, you might be sorry and not safe,” he said. Most states require rabies vaccinations for dogs every three years.
U.S. vet bill tops $670 million
Nearly 45 million American households include dogs, more than any other pet, and the nation’s canine veterinary bill runs more than $670 million a year, according to a survey by the American Pet Products Manufacturers Association.
In addition to the four deadly diseases, more than a dozen other “non-core” vaccines against diseases such as Lyme disease, intestinal parasites, kennel cough and others provide immunity that lasts only a year.
Vets often vaccinate for these ailments annually in large, multi-disease injections that Schultz says are often unnecessary.
If Lyme disease doesn’t exist in your area, don’t have your dog vaccinated for it, he said. If your dog is not going to be kenneled or boarded, don’t have it immunized for kennel cough.
“They give a lot of these vaccinations in ‘mambocombo’ injections,” he said. “Imagine what an assault it is to an animal’s immune system to have 12 or 13 vaccines injected at once.”
Although dog vaccinations, like human versions, kick-start the immune system to prepare antibodies and other immunity weapons for specific diseases, they can also be dangerous, Schultz said.
“The most common problem is anaphylactic shock,” he said, referring to the devastating and often fatal allergic reaction, “but there are others. Some vaccines can actually cause the disease or other diseases.”
Injections sickened cats
It hasn’t happened in dogs, but a cat vaccine was found several years ago to be causing fatal tumors at the injection site. At the same time, an aggressive animal biologics industry keeps turning out new vaccines.
One company released a vaccine this year against Western diamondback rattlesnake bites and is working on a version for bites by Eastern diamondbacks, which have a different kind of toxin.
During a lecture on dog immunology at the annual meeting of the American Veterinary Medical Association, Schultz dismissed one commonly used vaccine — for a disease called canine corona virus — as “a cure looking for a disease.”
Canine parvovirus became the fourth of the deadly “core diseases” in 1978 when a cat disease “jumped” to dogs, evidently because of their legendary fondness for cat feces.
“Thousands of dogs died, and veterinarians had never seen it before,” Schultz said. “They were familiar with distemper, but they’d never seen this before.”
Up to 80 percent of puppies with parvovirus die within 72 hours. A vaccine was developed immediately and was quickly used to control the disease.
The same year parvovirus appeared, Schultz reported that experiments in his Wisconsin lab indicated that vaccinations for distemper and canine adenovirus-2, which causes often-fatal hepatitis, appeared to last at least seven years. Further tests have since shown that parvovirus vaccine also lasts seven years, Schultz said.