This review intends to provide veterinarians with key facts and information relevant to serological testing of individual dogs and cats in the clinical setting. Specifically, this paper addresses the role of antibody testing for the core, vaccine-preventable diseases canine distemper virus, canine and feline parvovirus, and canine adenovirus.
Why did the veterinarian order the vaccination of the puppy with core vaccine component, 3 times at 3-week intervals?
For over a decade canine vaccine has been categorised into core, non-core and non-recommended groups, with canine distemper, parvovirus and adenovirus considered as the core vaccine components. These categories have been further developed and currently form the basis of the World Small Animal Veterinary Association (WSAVA) Guidelines for the Vaccination of Dogs and Cats.
With regard to vaccinations of puppies, the WASVA guide lines recognizes that maternally derived antibody (MDA) significantly interferes with the efficiency of most current core vaccines administered to pups and kittens in early life. The vaccine consists of attenuated living virus and therefore the antibodies identify it and lead to its destruction. As the level of MDA varies significantly amongst litters, the guidelines recommend the administration of multiple core vaccine doses to pups and kittens, with the final dose of these being delivered at 16 weeks or older and then followed by a booster at 6- or 12-months of age.
Vaccination of neonates and infants is problematic with two main issues: the immature immune system of neonates and the presence of inhibitory maternal antibodies.
When a pup is born, its immune system is not fully developed making it susceptible to a variety of infectious agents. Fortunately, this is not the case for most of the neonatal, as they can receive passive protection from their mothers through maternal immunity.
Passive immunity occurs by the passage of antibodies to the fetus through the placenta (~3%), and more significantly, by the absorption of maternal antibodies of the new born through the colostrum (~97%). Defined as the first 12-24 hours of milk flow following birth, colostrum is a highly concentrated mixture of large protein antibody molecules, vitamins, electrolytes, and nutrients. The pup can absorb the colostral antibodies into its blood system through the intestine only for its first days of life; the amount of absorption depending on the strength of each individual pup.
Unfortunately, the maternal antibodies will break down through natural aging of up to approximately 8-20 weeks. At this point the MDA decaying (Blue line in the graph below) may not provide optimal protection and may even act as inhibitor to the effectiveness of the vaccine (In between the two interrupted lines ~8-16 weeks). This situation is highly risky for the exposed and unprotected puppy. To avoid this situation the core vaccines are being given at 3-4 point intervals, as shown in the graph below.
Initial Vaccination (Dogs 16 Weeks of Age)
- Beginning as early as 6 weeks of age, the puppy is administered with sequential doses of a combination vaccine at an interval of 2 to 4 weeks until at least 16 weeks of age.
- Dogs that are 16 weeks of age when presented for initial vaccination should receive a second dose 2 to 4 weeks later.
- NOTE: Dogs residing in a HIGH-RISK environment may benefit from receiving a final dose at 18 to 20 weeks of age. HIGH RISK is a subjective assessment applicable to dogs residing at locations in which the incidence of CDV and/ or CPV is considered to be high; it may also include puppies known to have significant exposure to other dogs or contaminated environments.
- A single dose of a combination vaccine is administered within 1 year following the last dose in the Initial Vaccination series. Subsequent boosters should be administered at intervals of 3 year or longer.
- Measuring antibody levels (quantitative or qualitative) provides a reasonable assessment of protective immunity against CDV, CPV, and CAV2.
Using titer testing is a valuable investment for shelters to quickly identify, and manage the spread of infectious disease such as Parvovirus, Distemper and Panleukopenia. Prompt identification of these diseases simply helps save resources, time, and most importantly our pets lives. It is as simple as this.
How can VacciCheck help?
Titer testing is often underutilized in the field of shelter medicine due to cost. VacciCheck though, is an in-shelter titer test, that makes titer testing and disease surveillance easier, faster and more affordable, when compared to other alternatives. The Maddies Fund discusses in depth the use of titer testing in general, and VacciCheck in particular.
What do the vaccination guidelines recommend?
The latest WSAVA Vaccination Guidelines recommends titer testing, such as VacciCheck, for the following 2 reasons:
- If there is a disease outbreak within a shelter: all animals within the shelter should be titer tested for Distemper and Parvovirus (dogs/puppies) or Panleukopenia (cats/kittens). If protected, our pets should not become infected or possibly die. Simple and clear thinking. Protected pets can then be separated from non- or low-responding animals.
If our pets test negative, it indicates that these animals are susceptible to the disease and should not be taken out of the shelter until after the incubation period for the infection. These animals should be vaccinated and then retested to confirm that they test positive after the incubation period mentioned above.
- For animals outside of a shelter needing to be admitted in the face of a disease outbreak in the shelter, if the pets test positive with VacciCheck, they may safely enter the shelter as they are protected from disease.
If the pets test negative, these animals should be vaccinated and sent to foster homes until after they have developed protection for these diseases. They should not be allowed to enter any shelter until they are testing positive.
The new AAHA Vaccination Guidelines describe how to use titer testing via their flow chart.
As important as it is for us to care for our own pets, it is just as important to protect all animals in all shelters.