“Vaccinate as many dogs as possible but only as often as needed”
“Vaccinate as many dogs as possible but only as often as needed” - that’s the motto of leading veterinary associations such as the World Small Animal Veterinary Association (WSAVA). Vaccines continue to be life-savers for people and animals.
Vaccinating as many dogs as possible is essential to reach the so-called herd immunity: in order to avoid epidemics, we should aim for the highest possible vaccination coverage of the dog
population (at least 70%). While this can be achieved by awareness campaigns, the “only vaccinate when needed” part is just as important. And here’s where in-house antibody tests such as the
Fassisi
CantiCheck Plus kit come in.
Tailor-made vaccination protocols
According to the WSAVA vaccination guidelines group, the ‘necessary’ or so-called core vaccines for dogs include those against canine distemper virus (CDV), canine adenovirus (CAV types 1 and 2)
and canine parvovirus (CPV)1. Tailor-made vaccination protocols are key: together with the dog owner, the vet should set up a tailor-made vaccination protocol. What is the age, origin and
lifestyle of the pet? Does it travel or will it spend time in boarding kennels? Is it used for breeding, showing or competitions? Whatever their lifestyle, all dogs will require core vaccines,
defined by the WSAVA as those “that all dogs throughout the world should receive to protect against infectious diseases of global significance”. Additionally, non-core vaccines can be given,
according to the lifestyle.
Core vaccines: not more than once every 3 years
But even core vaccines should not be given needlessly. According to the WSAVA, they should not be given any more frequently than every three years following the primary vaccination series, which
includes the first booster following the puppy series. The reason is simple: the duration of immunity (DOI) is many years and may be up to the lifetime of the pet.
For the core vaccines, the WSAVA guidelines specify that the presence of antibodies – regardless of the titre – indicates protective immunity and immunological memory. They even stress that
“giving more frequent vaccines to animals in an attempt to increase antibody titres is a pointless exercise”.
In-house antibody testing: when to use?
Checking for the presence of antibody for core vaccine components (CDV, CAV, CPV) is therefore a useful tool to determine immune protection, and the use of in-house tests is supported by the
WSAVA guidelines. Ideal tests are fast – providing the result in minutes – and provide a simple “yes/no” answer, such as the Fassisi CantiCheck
Plus kit, which tests for the presence of CDV. CAV and CPV antibodies.
This test has several applications:
- to check the protective immunity in puppies
- to determine the immune status of dogs
- when managing infectious disease outbreaks in shelters
- in case of adverse events
Is my puppy safe? Measuring vaccine take-up
According to the WSAVA guidelines, the third dose of core vaccines should be administered at 16 weeks of age or older. Testing puppies at 20 weeks of age will show which ones are seropositive –
and therefore protected. Seropositive puppies would not require their 26 or 52-week booster and could next receive their core booster 3 years later.
Seronegative puppies should be revaccinated and retested to check they are able to developing protective immunity. Those that fail to respond after revaccination may be either ‘low responders’ or
genetically-determined ‘non-responders’ incapable of mounting an immune response to that antigenic component of the vaccine. Such animals are rare, but certain breeds such as the Rottweiler are
predisposed to developing a less effective immune responses to CPV and rabies virus.
If and when to jab: determining the immune status
Another indication is to determine the protective status of a newly adopted dog of unknown vaccination history – or even one that has not been revaccinated for some time. Most vaccinated dogs
retain protective antibodies against CDV, CPV and CAV for many years. This means the dogs should be revaccinated only if the antibodies are absent. Antibody determinations to other vaccine
components are of limited value because of the short ‘life span’ of these antibodies or the lack of correlation between antibody titres and protection (e.g. Leptospira).
Many veterinary practices that have embraced the ‘annual health check’ routinely offer serological testing instead of a booster every three years. Pet owners like this option, and it also makes
more sense to determine whether a core vaccine is required than to give a vaccine unnecessarily. While triennial ‘antibody testing’ is sufficient in adult animals, annual testing is advised in
dogs over 10 years of age.
Is this rescue dog protected against distemper and other potentially harmful diseases?
There’s only one way to determine the protective status of a dog of unknown vaccination history – or even of one whose vaccines have ‘lapsed’: a serological tests such as the rapid in-house Fassisi CantiCheck Plus test.
Who’s protected and who’s not? Managing infectious disease outbreaks
In-house serological testing has revolutionized the ability of the veterinarian to manage infectious disease outbreaks in animal shelters – particularly CDV or CPV outbreaks. All animals in the
shelter should be tested. If the animals are seropositive, this means they are protected. Seronegative (susceptible) animals should be separated and vaccinated. They should not be adopted out of
the shelter until after the incubation period for the infection and seroconversion (2 weeks for CPV, 6 weeks for CDV). Animals outside the shelter needing to be admitted during a disease outbreak
should also be tested. Seropositive (protected) animal scan safely enter the shelter and be housed with other seropositive dogs, but seronegative animals should be vaccinated and kept in foster
homes until they seroconvert.
In case of adverse events: when to avoid vaccines
If an animal has a history of an adverse event following vaccination, serological testing can be used to check if core revaccination is necessary. If vaccination is suspected as a trigger factor
in an adverse event, such as in immune-mediated disease, then vaccination should be avoided if at all possible. As long as dogs remain seropositive for CDV, CAV and CPV they do not require
revaccination. The use of non-core vaccines in such dogs should be considered carefully.
Rapid in-house tests such as the Fassisi CantiCheck Plus kit can help determine the immune status of dogs against CDV, CPV and CAV and reduce the
frequency of unnecessary vaccinations.
CanTi Check Plus
The rapid in-house test CanTi Check Plus developed by Fassisi will detect antibodies against parvovirus, adenovirus and distemper.
All you need is a single blood sample: within minutes the test will reveal whether the patient has circulating antibodies against canine parvovirus (CPV) canine distemper virus (CDV) and/or
canine adenovirus (CAV). For these three parameters a clear correlation between antibody levels and protection against clinical signs has been proven. Detection of existing circulating
antibodies indicates the presence of immunity and does not require re-vaccination.
The test will assess the immune status of the dog. Serum, plasma or blood can all be used as a sample. A positive result means the dog has an active immunity against the virus in question,
meaning it is protected against the disease(s) and does not require vaccination. Fassisi rapid tests allow a pet-side check, whether at the veterinary practice or on location (breeders,
shelters).
The rapid in-house CanTi Check Plus test will help you develop a tailor-made vaccination protocol, ensuring effective protection while reducing the frequency of unnecessary
vaccinations.
Core vaccines at a glance
According to WSAVA, core vaccines are those “that all dogs throughout the world should receive to protect against infectious diseases of global significance”. Let’s take a closer look at the
diseases we need to protect our pets against:
Canine parvovirus (CPV) is a highly contagious virus that can cause acute gastrointestinal disease in dogs. There are currently three variants: CPV-2a, CPV-2b and CPV-2c. The
original CPV-2 variant is rarely isolated nowadays. The most recent variant to emerge is CPV-2c and this genotype is recognized in North and South America, Europe, Africa and Asia. Parvoviruses
are highly pathogen and infectious, and all three variants of the virus survive up to several months in the environment.
The disease most often affects puppies between six and 20 weeks of age, but older animals can also be affected. Typical clinical signs associated with CPV include a sudden onset of high fever,
vomiting and haemorrhagic diarrhoea. In puppies, the CPV can also affect the bone marrow and lymphopoietic tissues as well as the myocardium. The disease is potentially fatal. Treatment is not
always successful
The disease is preventable by vaccination. Current WSAVA guidelines recommend puppies to be vaccinated with modified live virus (MLV) vaccines at 6 to 8 weeks of age, then every 2-4 weeks until
16 weeks of age. Following this, a first booster should be given at 6 months or 1 year of age, after this not more than once every 3 years.
Canine adenovirus type 2 (CAV-2) is related to the hepatitis virus or canine adenovirus type 1. CAV-2 is used in vaccines to protect against cause infectious canine hepatitis
(ICH) and against infectious tracheobronchitis. The virus
In puppies, ICH can cause fever, depression, oedema of the head and neck and jaundice. In severe cases, ICH can be fatal. In the mild form, dogs may show a decreased appetite, lethargy and a mild
fever. Some dogs develop opacity (cloudiness) of one or both corneas of their eyes (so-called blue eye) one to two weeks later. Dogs may have respiratory signs (cough, nasal discharge).
Vaccination is highly successful in preventing the disease. Parenteral CAV-2 MLV vaccines are recommended for the prevention of ICH and the reduction of respiratory disease associated with CAV-2
infection. Intranasal CAV-2 vaccines are not intended for the protection against ICH, but only for the prevention of respiratory signs.
Current WSAVA guidelines recommend puppies to be vaccinated at 6 to 8 weeks of age, then every 2-4 weeks until 16 weeks of age. Following this, a first booster should be given at 6 months or 1
year of age, after this not more than once every 3 years.
Canine distemper virus (CDV) is a morbillivirus that causes distemper (hard pad, footpad disease) in dogs. The virus causes immunosuppression and affects several body systems,
including the gastrointestinal, respiratory and nervous systems. Clinical signs vary widely and include high fever, vomiting and diarrhoea, nasal discharge, dehydration, excessive salivation,
coughing and/or laboured breathing, anorexia and weight loss. Central nervous signs can range from twitching, convulsions, circling and ataxia to paralysis. The disease is often fatal. Dogs that
survive often develop hyperkeratosis of the paw pads and nose, and may suffer from degeneration of the nervous system.
The recommended vaccines are modified live virus (MLV) and vectored recombinant vaccines (rCDV). Current WSAVA guidelines recommend puppies to be vaccinated at 6 to 8 weeks of age, then every 2-4
weeks until 16 weeks of age. Following this, a first booster should be given at 6 months or 1 year of age, after this not more than once every 3 years.
Not surprisingly, puppy vaccines are often presented as a multivalent core vaccine against all three diseases. Similarly, the Fassisi CantiCheck
Plus is a multivalent core test, as it can help determine the immune status against all three viruses in one go.
Antibody titre testing in practice: commonly asked questions
Are serum antibody titres useful in determining vaccine-induced immunity?
Yes. The WSAVA guidelines emphasise that this is “particularly the case for CDV, CPV-2 and CAV-1”. However, serum antibody titres “are of limited or no value for most other vaccines”.
How long after CPV-2/CDV vaccination should I wait before doing an in-clinic antibody test?
This depends: if a puppy receives its final primary vaccine at 16 weeks of age, then it may be tested from 20 weeks of age onwards. Any antibody present at that stage cannot be of passive,
maternal origin and therefore indicates that the puppy is actively protected.
Adult vaccinated dogs are likely already to have serum antibodies present at the time of booster vaccination, regardless of how long an interval there has been since they were last
vaccinated.
Can antibody tests such as CanTi Check Plus be used to test for the presence of maternal antibodies and determine the time of first vaccination?
Theoretically – yes. However, it would be very difficult and expensive to repeatedly sample and test young puppies in order to monitor the decline of maternal antibodies. That’s why the WSAVA recommends vaccinating at repeated intervals starting at around 6-8 weeks of age until 16 weeks of age, to cover the so-called immunity gap.
What happens to the antibody titre over the 3-year period post-vaccination?
For CDV, CAV-2 and CPV-2, the antibody titre “will be consistently present at similar titre,” according to the WSAVA guidelines. This has been shown in numerous field serological surveys of dogs
last vaccinated up to 9 years previously and in experimental studies for dogs last vaccinated up to 14 years previously. For other vaccines, such as Leptospira, the titres will decline rapidly
after vaccination.
Can dogs be tested as an alternative to annual vaccination?
Yes, certainly. Validated in-practice serological test kits such as CanTi Check Plus will help determine of the presence of protective serum antibody specific for CDV, CAV and CPV-2. In certain
countries, such kits are used to confirm protection at 3-yearly intervals instead of automatic revaccination for core diseases. If you were to collect and test samples in your practice, you will
quickly find that annual testing is unjustified.
References
- Day MJ et al. Guidelines for the vaccination of dogs and cats compiled by the vaccination guidelines group (VGG) of the world small animal veterinary association (WSAVA). JSAP (2016) Vol 57
- Day MJ. The Role of Serology in Vaccination Decision Making. WSAVA Congress Proceedings, 2017
