Vaccines and why we think they are so important

Our senior vet Tony talks about the advances in vaccinations for Dogs & Cats.

The successful development of vaccinations is the area of veterinary medicine that has probably had the most beneficial impact on animal welfare. Before vaccination, many animals, particularly young ones, became ill and often died from serious infectious diseases. These diseases include distemper, hepatitis & parvovirus in dogs, and, for cats, infectious enteritis & the upper respiratory diseases known as “cat ’flu”.

Distemper is rarely seen these days, but was quite common in our area up to the 1980s. It is a virus (related to the human measles virus) and causes vomiting & diarrhoea, and a cough, runny nose, and runny eyes. The virus later damages the nervous system, and the dog can then develop epileptic fits which often become progressively more severe, and can be ultimately fatal. The vaccine is very effective at protecting against the disease. You might ask why is it worth protecting against this virus if it is now rare –however, if we get a reasonable percentage of the dog population who are susceptible, and the disease does get introduced, many dogs can quickly succumb. These affected individuals will shed large amounts of the virus and so infect other susceptible individuals, and an epidemic occurs. If 90%+ of the dog population is protected, then the disease if much less likely to spread –this is sometimes called “herd immunity”.

Infectious canine hepatitis is caused by another virus (adenovirus 1) and, as its name suggests, causes liver damage. It can also affect the respiratory system, causing a sore throat & cough. The cornea -the clear outer part of the eyes -may appear cloudy or bluish, and the kidneys are commonly affected as well. In some, especially young individuals, the disease can be so severe that they can die within hours of first showing symptoms. Vaccination is extremely effective at preventing the disease –this vaccine gives almost 100% protection.

Parvovirus causes a severe gastroenteritis, and affected dogs become very poorly with vomiting and diarrhoea which is usually bloody. Affected individuals become dehydrated very quickly. As the disease is caused by a virus, there is no specific treatment –therapy is aimed at reversing the dehydration with intravenous fluids (a “drip”), and supportive treatment to reduce the symptoms. It can take days of hospitalisation before the animal’s own defence system gets on top of the virus, and not all animals will recover despite round-the-clock intensive care. This particular disease is still frequently seen in our area, and is highly infectious. It is very preventable – modern vaccines are very effective at providing protective immunity.