Vaccination and Your Pet Part 2

ADULT ANIMALS

Most of the controversy surrounding pet animal vaccination is centred on the practice of annual vaccination of adult animals. This has been the focus of much veterinary research and now it is widely accepted by the profession that annual vaccination against all diseases is not required, although there are some where it is still vital.

The most important time to vaccinate an adult animal is when they reach a year old and have their first annual vaccine. This is because there will be a small percentage of animals who did not gain adequate protection from their initial vaccine course and this first annual vaccine should be enough to boost their levels.

For dogs there are now several vaccines against which protection has been shown for at least three years. These include Parvovirus, Distemper and Canine Adenovirus. Vaccinating against these diseases more frequently than every three years is unlikely to be helpful. However, it is sensible to re-vaccinate animals during outbreaks of disease, when they could be exposed to high levels of the viruses. Annual vaccination is still important for Leptospirosis, which is a nasty disease that can cause both liver and kidney failure and is transmissible to humans. It is given as a killed virus so the protection only lasts around a year. This is the protocol that the majority of vets now follow and if you check your dog’s vaccine record, you should see that they are not given a ‘full’ booster every year.

It is possible to take blood tests (titres) to measure the levels of protection in individual dogs, which can help decide if they need vaccinating or not. However, these tests do not exist for all of the infectious diseases we can protect against and none exist for cats.

There is much less information regarding feline vaccinations and the length of protection they give. This is due to both a lack of studies into this subject and also the fact that, especially for cat flu, there is a large variation in the viruses that cause the disease which makes guaranteeing longer protection difficult. Cat flu is caused by two different viruses, Feline Calicivirus (FCV) and Feline Hepatitis (FHV), and it has been suggested that vets could decrease the vaccination frequency to every three years. The Ass Board Cat Disease (ABCD) advise that cats whose lifestyles mean they are at higher risk of disease; those who go outdoors, or who regularly visit catteries, should be vaccinated every year against both cat flu viruses but for those who are indoor animals and don’t go to catteries, every three years is probably adequate. Feline Enteritis, which is effectively feline Parvovirus, has similar lengths of protection and it is possible that a single vaccine can give lifelong protection. Feline Leukaemia (FeLV) is the final disease against which cats can be vaccinated, it is similar to human leukaemia in that it is a cancer of the immune system, but it is different because it is virally transmitted. It is more prevalent in younger cats and as they age they become more resistant to infection. For this reason the ABCD advise annual vaccination against FeLV up until the age of four years, and then every three years after that.

One of the reasons vets have traditionally advised annual vaccination in pets is so they visit the surgery every year and can receive a full health examination. This is extremely important as a way of picking up early signs of disease and problems and if you chose to not vaccinate your pet every year, you should at least, as a responsible pet owner, take them for an annual check-up. Remember, not being seen for a year in an animal’s life, is the equivalent of a human not visiting the doctor for 7 years.


VACCINE REACTIONS

Many pet owners are concerned about the possibility of vaccine reactions and adverse effects of vaccinations but extensive studies have proved that vaccinations are extremely safe. A review produced in 2001 of all the available published information at that time showed a suspected vaccine reaction in 0.004% of all vaccines administered in cats and dogs. The symptoms of which were mainly mild swelling or itching at the vaccine site, some lethargy and transient fever. There has also been a lot of concern, particularly in the USA, about vaccine related sarcomas. These are aggressive tumours that can occur at the site of a vaccination, most commonly on the back of the neck. Studies are underway in the UK to assess the risk of VSR but the incidence is considered small (1-2 cats per 10,000 vaccinated). So, although vaccine reactions do occur, they are rare, usually mild and the benefits of the protection the animal receives are considered to far outweigh these risks.


Vaccination of pets is vital and should be done in all animals on a regular basis. This is not only to protect the individual but also to provide ‘herd immunity’ and stop viruses taking hold in the pet population. If you don’t vaccinate your pet and it has never been ill, you may be benefitting from this population immunity and the fact the majority of responsible pet owners do ensure their animals are protected. Vaccines have all but eradicated many fatal viruses, it is now very rare to see a case of Canine Distemper and Parvovirus only tends to occur where there are pockets of unvaccinated dogs. This is a huge success for the veterinary profession and one which should be roundly celebrated. Also, thanks to improvement in vaccines, the duration of immunity in many now lasts several years, something which vets have recognised and they have changed their vaccine protocols accordingly.

These are some web sites which are very useful to read if you want more information on this subject. They are all well balanced, well researched and written by highly qualified veterinary surgeons.

http://www.wsava.org/PDF/Misc/VGG_09_2007.pdf

http://www.noah.co.uk/papers/vpc-catdogvetsurv.pdf

http://www.pet-informed-veterinary-advice-online.com/how-do-vaccines-work.html#vaccine-work

http://www.hcvma.org/notes/SpeakerNotesRichardFord.pdf