By David F. Kramer
The last 20 years has seen a growing anti-vaccination movement, which ostensibly began with a since debunked study published in 1998 that linked a common childhood vaccination with a little understood brain disorder. It led, and continues to lead, many parents to opt out of core vaccinations for their children. Admittedly, much of the furor has been internet and media driven, but it has made many people take a second look at the issue of vaccinating as a whole. Members of the veterinary community report that they are also seeing a decrease in vaccination.
To address the concerns of pet owners, a procedure called the titer test can be used to help determine the need for vaccination.
What is a Titer Test?
A titer test involves measuring the level of antibodies against a particular disease in a sample of blood. Antibodies are produced in response to an antigen, or stimulus. Some typical stimuli that can produce this response include infection with bacteria and viruses and vaccination.
When a pet (or person) is vaccinated, the body creates an immune response, in part, by producing specific antibodies against the antigens in the vaccine. Thereafter, the immune system is able to quickly recognize that attacking microorganism and launch an effective defense. According to Dr. Jennifer Coates, veterinary advisor with petMD, “when a pet’s vaccine titer test comes back as being ‘protective,’ if that individual were to be exposed to the disease in question, he or she should be able to fight it off.”
But the veterinary community is somewhat divided on the particulars of this issue.
Dr. Adam Denish of Rhawnhurst Animal Hospital in Pennsylvania has some special concerns when it comes to the issue of vaccination and titer tests.
“I own two animal hospitals and a boarding kennel, so we do recommend vaccinations based on the risk for that animal. It is my opinion, and the opinion of other doctors, that vaccination is the right way to go for most of these animals," says Denish. “Sometimes owners ask for a titer level, and if they’re acceptable for both distemper and parvo, then that dog gets an extra year before we test it again. While most vaccines do last longer than the manufacturer recommends for a booster, no one knows for sure.”
Titer screenings in pets can play a role in the decision of when to vaccinate, but Coates adds another note of caution.
“Because the immune system is composed of many more parts than just antibodies, low vaccine titer tests can be hard to interpret. Does this really mean the pet is at risk for this disease? No one really knows.”
State Laws and Core Vaccinations
“What I suggest for puppies and kittens is to vaccinate according to state law, which is typically just rabies,” says Dr. Patrick Mahaney, a Los Angeles-based holistic veterinarian. “Then I’ll also vaccinate for what are considered to be core diseases—those which are most likely to cause your pet to get severely sick, such as canine distemper virus (CDV) and canine parvovirus (CPV).”
Mahaney says he also sometimes recommends vaccinating against “other agents which are not considered to be as serious, and are therefore considered ‘non-core,’ such as adenovirus and Bordetella (aka kennel cough).”
Veterinarians look at a variety of factors when it comes to determining if and when an adult animal needs a booster including the individual’s lifestyle and risk factors, disease prevalence in the area, and the manufacturer’s instructions. For those who are concerned about over-vaccinating their pets, a titer test can provide evidence as to whether an animal has antibodies against a disease, or whether a booster might be a good idea.
On the negative side, Denish says there is no way to predict antibody levels three or six months down the line. Resistance levels can change due to any number of factors, including stress, disease, and medication, so there is a concern that these levels might not be consistent over time.
As the owner of a boarding kennel, Denish prefers more proof of an animal’s resistance before risking exposure to other animals in his care. There is no titer test for Bordetella, for example, so he prefers to play it safe rather than risk a kennel cough infection spreading throughout a group of boarded animals, as well for the protection of those dogs the infected animals might contact.
How Money Influences Vaccines
Some veterinarians express concern that the companies that make vaccines are most interested in moving their products, and in the process, pressure veterinarians to push vaccines even when they are not needed. And since money can be made on vaccines, some vets go along with it.
“Veterinarians commonly make money off of vaccines because the cost is very minimal, so they mark up the cost of providing a vaccination,” says Mahaney.
Some markup is to be expected of course, since administering the injections takes time and labor on behalf of the veterinarian or veterinary technician. For vets who are recommending, and providing, three or four vaccines in one session, a small profit can be made.
“Such is the case with mobile vaccine clinics,” says Mahaney, “it’s a method of generating practice income without having high overhead.”
But titer tests often end up costing owners more than vaccines. According to Denish, a distemper-parvo battery titer costs about $76, while the vaccine is about $24. Because there is always the chance that an already paid for titer will show that a vaccination is required anyway, many owners would just as soon opt solely for the vaccination, if only for financial reasons.
Adverse Reactions to Vaccines
Vaccines rarely produce illness because they are made either from tiny, replicated parts of the disease-causing microorganism or from germs that are dead or have been very much weakened. This helps the body to build immunity without making the recipient sick. To be sure, full immunity is not 100% certain for all vaccinated pets and some individuals can have allergic or other adverse reactions to vaccines, but on the whole, the benefits of appropriate vaccination far outweigh any risks.
According to Mahaney, while adverse reactions to vaccines are the exception, these events are more likely to occur when pets are already sick with immune mediated diseases or cancers (e.g., lymphoma, multiple myeloma, leukemia, or tumors) or are taking drugs that suppress the immune system, such as with steroids or chemotherapy. Additionally, some smaller breeds, such as Chihuahuas, Pugs, and Yorkshire Terriers, are more predisposed to problems associated with vaccination.
Adverse reactions to vaccines can occur within minutes or hours after a dose is given, or can manifest over a longer period of time. Symptoms of an allergic reaction to a vaccine include hives, vomiting, diarrhea, low blood pressure, decreased appetite, lethargy, swelling, collapse, and rarely coma or death.
Are Vaccines Overused?
“I do believe that vaccinations are probably overused,” says Denish, “but the purpose of coming to a veterinarian on a yearly basis is to make sure that your animal is healthy. Vaccinations, while important, are secondary to other health issues, such as heartworm, Lyme disease, and fecal testing [for parasites].”
What compounds the problem, Denish says, is that when vaccine manufacturers improve their products to last longer, pet owners can sometime use this as a reason to visit their vet less often. Sometimes, owners will only bring their pets to a veterinarian when a groomer or kennel requires documentation of vaccination before offering their services.
On the other hand, “fear that their pets will acquire a disease prevented by vaccines motivates many owners to pursue vaccination despite the potential for a pet to still have immunity from his previous vaccinations,” says Mahaney. “Additionally, many owners don’t consider the overall state of health of the pet, and the diseases that are actually present in the body, like periodontal disease and obesity, [which] are often not fully addressed during routine appointments for vaccinations.”
So, while the jury may still be out on the issue of vaccination versus titer testing, this conflict is no excuse not to take your pet to his or her veterinarian for regular examinations. Frequent checkups will do far more to ensure the continual health of your pets than relying on vaccination or titer testing alone.