Q & A: The “V” Word (Vaccines)

By Dr. Kim Everson, DVM

 

Question: I’ve heard that vaccinating my pet is unnecessary and possibly dangerous. Is this true?

 

Answer: The topic of vaccinations has been heatedly debated in recent years. Used properly, vaccines save lives and preserve the human-animal bond.

Vaccines have greatly reduced outbreaks of diseases that have historically killed scores of animals. Some vaccines not only prevent disease in an individual animal, but also secondarily provide protection against that disease for people. This is true of dangerous or deadly zoonotic diseases–such as leptospirosis and rabies virus–that can be passed from wildlife through pets to people.

A big concern about vaccination is over-vaccination. One argument is that animals are being given vaccines they do not actually need. A number of vaccines currently available are useful and effective but are necessary only for certain animals. These vaccines are considered “optional” or “lifestyle” vaccines and include Lyme, Bordetella (Kennel Cough), feline leukemia virus (FeLV) and sometimes leptosporisis. Animals with high exposure to these diseases benefit from being vaccinated. Interestingly, while the “core” vaccines (discussed below) have longer duration of immunity, the “lifestyle” vaccines must be given at least annually to maintain effectiveness. You should discuss with your veterinarian whether your pet needs these vaccines each year because many pets’ needs change over time.

Core vaccines are those such as rabies and “distemper” that are essential for protecting the canine and/or feline population at large (as well as humans in the case of rabies virus). “Distemper” is the name of a disease but also the broad term used to describe one of the core combination vaccines available for dogs and cats.

In cats, “distemper” is also called panleukopenia. It is a highly contagious virus that causes severe immune suppression, gastrointestinal and neurological symptoms and death. Feline “distemper” vaccines often protect against upper respiratory illnesses caused by calicivirus and herpesvirus as well as panleukopenia. In dogs, the distemper virus causes serious to fatal respiratory, neurological and/or gastrointestinal illness. Other components of canine “distemper” vaccines vary but typically include parvovirus, parainfluenza and canine adenovirus-2 (hepatitis and respiratory illness).

Another legitimate concern regarding over-vaccination is that some adult animals are vaccinated repeatedly when in reality they may have plenty of immunity left over from a previous vaccination. Titer testing is becoming more popular to counteract this tendency. A titer test is a blood test to show if a pet has a sufficient level of protective antibodies. If a pet’s titer comes back high enough it may not need to be vaccinated for that particular disease again that year. Many veterinarians offer titer testing.

Baby animals and those with a sketchy vaccine history should not be considered in the “over-vaccination” argument. There are many scientifically proven reasons for boostering more than once in these animals. Boostering increases long term “memory” in the immune system making vaccination more effective. Moreover, puppies and kittens need multiple distemper boosters in case they did not receive enough maternal antibodies in their mother’s colostrum (first milk) to protect them from disease over the first months of life. Ironically, maternal antibodies interfere with the young animal’s ability to create its own antibodies until 16 weeks of age. This is when puppies and kittens typically receive their final set of vaccines because their maturing immune system is now fully functional.

Vaccines, like all medicines, provide many benefits to health but are not completely without risk. Most animals respond as expected to vaccination and enjoy the benefits of protection with just a moment of minor discomfort. A potential side effect of vaccination in some pets is vaccine reaction, the severity of which ranges from mild GI upset to moderate facial swelling to (rarely) severe anaphylactic shock. There is speculation and suspicion that some cases of auto-immune disease may be triggered by vaccination; however, multiple factors are involved in auto-immune diseases and it is extremely difficult if not impossible to pinpoint a single known trigger. Because side effects are rare, the benefits of vaccination outweigh the risks for the majority of animals.

When it comes to vaccinating your pet, it is important to make an informed decision. Remember, vaccines were developed for a reason: to protect life. Because contagious diseases have ruined so many lives among human and animal communities, vaccines were developed to offer protection to the individual as well as the population as a whole. However, just because a vaccine is available does not mean it is necessary for your pet. Start a conversation with your veterinarian about your pet’s vaccine requirements and ask if titer testing is appropriate for your pet.

 

Originally printed in Pet Journal, January 2013