Veterinarians divided when it comes to immunity
JoAnna Lou | February 22, 2013

Dr. John Robb leads a protest outside of his former veterinary practice.
For years people suspected that pet vaccines didn’t need to be administered annually and that immunity was more similar to human shots. Fortunately in the last ten years, veterinary colleges and organizations, such as the American Veterinary Medical Association (AVMA) and the American Animal Hospital Association (AAHA), revisited their guidelines and now recommend administering core vaccines every three years. It’s even becoming more common to find veterinarians who measure antibody levels through blood titers instead of defaulting to regular booster shots (this is one of my requirements when choosing a vet).

But even with the AVMA and AAHA constantly revisiting their guidelines, pet vaccines remain a tricky topic. It’s further complicated by the fact that many studies are sponsored by vaccine manufacturers, which creates a potential bias. Dr. Richard Ford, a 2003 AAHA Canine Vaccination Guidelines Task Force member, has said that the decision to recommend a three year re-vaccination schedule was an arbitrary compromise that was not based on science.

And frequency isn’t the only controversy. Earlier this month, a Connecticut veterinarian had his practice taken away from him after Banfield found out that he had been administering half-dose vaccinations. Dr. John Robb believes that it’s not safe to use the same dose for all dogs and cats, particularly for the smaller breeds.

Dr. Robb bought his Stamford, Conn. Banfield franchise in 2008, a year after the veterinary hospital chain was acquired by Mars and PetSmart. He believes that the corporations are not only unfairly targeting him because they want to ultimately cease franchise ownership for their hospitals, but are jeopardizing the health of his clients’ pets.

There are definitely arguments for both sides of the issue, but I can see where profits and insurance risk could create a conflict for a medical organization owned by two big corporations.

AAHA President Dr. Mark Russak believes that Robb is putting pets at risk and creating a potential public health concern with incorrectly administered rabies shots. He says that vaccines are manufactured through scientific trials to determine the correct amount of antigens needed to stimulate the immune system.

But while many veterinarians disagree with Dr. Robb’s vaccine protocol, Jean Dodds, a leading expert in this area, says that dosages can be adjusted safely. She has been vaccinating toy breeds with half doses for years and is currently spearheading a campaign to increase the rabies vaccination interval from three to five years with the hope of eventually changing it to seven.

A 2002 study published in the Journal of the American Veterinary Medical Association showed that there are potential problems with using a universal dosage. The research documented a higher incidence of vaccine-associated adverse events in dogs less than 22 pounds (27 percent versus 12 percent for dogs over 22 pounds with each subsequent shot).

The fact that there is so much division among veterinarians on this topic just goes to show that more work must be done in this area to develop guidelines we can trust.

New study looks at the health implications of spay/neuter
JoAnna Lou | February 19, 2013

I affectionately call Nemo my “monster Sheltie” since he measures 19.5 inches at the shoulder, three and a half inches over the breed standard. Due to his big size, he often gets mistaken for a small Collie. On the recommendation of my veterinarian, I had Nemo neutered at 16 weeks old, which I later suspected may have contributed to his extra large stature. Canine sports medicine specialist Dr. Chris Zink DVM has compiled a lot of research showing that neutering a dog before their growth plates close may cause extra growth and, more importantly, possible health implications.

Researchers at the University of California Davis recently published a study that highlights the need for more work in this area. The team looked at the health records of 759 Golden Retrievers, examining the relationship between neutering and two joint disorders and three cancers (hip dysplasia, cranial cruciate ligament tear, lymphosarcoma, hemangiosarcoma and mast cell tumor). The dogs were classified as intact (not neutered), neutered early (before 12 months age), or neutered late (at or after 12 months age).

Joint disorders and cancer are of particular interest because neutering interrupts the production of certain hormones that influence the closure of bone growth plates and regulation of the estrous cycle in female dogs.

The University of California study found that the rates for all five diseases analyzed were significantly higher in neutered males and females (whether they were neutered early or late) as compared to intact dogs.

Specifically, early neutering was associated with an increase in the occurrence of hip dysplasia (a 100 percent increase!), cranial cruciate ligament tear and lymphosarcoma in males and of cranial cruciate ligament tear in females. Late neutering was associated with the occurrence of mast cell tumors and hemangiosarcoma in females.

The lead investigator, Benjamin Hart, says that it’s important to remember that the effects of early and late neutering may vary from breed to breed, since vulnerabilities to various diseases differ.

Knowing this information, it makes a compelling case to get a vasectomy for male dogs (eliminates sperm without effecting testosterone levels) instead of a standard neuter. Unfortunately female dogs don’t have an easy alternative.

No matter what, considering how many dogs are neutered early in this country, it’s important that more research is done in this area. However, I hope that this study doesn’t discourage people from neutering dogs all together. I think we’ve come a long way in promoting spay/neuter to help control the overpopulation problem (and still have a long way to go). But more research in this area would help us come up with a birth control solution that limits adverse effects on health.

For another view on this study, from a shelter worker, see Shirley Zindler’s post.

Originally published in “The Bark” at www.thebark.com