Vaccines are essential to protect against disease, they help to introduce an agent similar to the actual infection that stimulates the immune system of the recipient
The vaccination process normally contains benign reactions.
Because vaccination technology has evolved, benign reactions are much less frequent than they were before.
Since vaccines have become much purer and less likely to trigger a response, then acute allergic reactions to the vaccine are also very rare. They usually cause swelling of the face and / or limbs that occur rapidly after vaccination, but they can also cause acute anaphylactic shock, where the animal develops breathing difficulties and collapses.
This type of reaction generally occurs very soon after vaccination, and immediate veterinary attention should be sought.
Many longer term reactions have been suggested but never proven, because it is really difficult to prove a cause and effect relationship – when so many animals are being vaccinated, a proportion will become unwell in the period afterwards just due to statistical probability.
Any swelling that persists for more than a few days at the site of an injection should be checked over by a vet. Severe reactions such as this are thought to occur in approximately one in every 10,000 cats vaccinated.
A Suspected Adverse Reactions (SAR) Surveillance Scheme (SARSS) is run by the Veterinary Medicines Directorate for licensed veterinary medicines (see www. vmd.defra.gov.uk). Less than one adverse reaction for every 10,000 doses sold relate to vaccines, and of these only three per cent report the possibility of an associated injection site sarcoma.
Feline Infectious Enteritis
Also known as feline panleukopenia virus, this can be responsible for a severe and often fatal form of gastroenteritis.
Two viruses, feline herpesvirus and feline calicivirus (FCV), are responsible for most cases of cat ‘flu, or acute upper respiratory tract disease. These viruses are extremely common, and infection results in sneezing, nasal discharge, conjunctivitis, ocular discharge, mouth ulceration and a sore throat. Following infection many cats remain carriers of these viruses (although they may no longer show signs of disease), thus acting as a source of infection for others.
Feline Leukaemia virus
Some are able to fight off an infection, but cats that remain infected with the virus generally die or are euthanized within three years of being diagnosed with the infection, due to damage to the immune system, progressive anaemia, or the development of tumours (lymphoma).
This bacterium is probably most familiar to pet owners as one of the causes of kennel cough in dogs but it can also cause upper respiratory tract infection in cats.
This is a type of specialized bacterium that mainly causes conjunctivitis. It is very fragile and cannot survive in the environment, so is transmitted by direct contact between cats. Infection is most common in young cats from multi-cat households.
Infection results in mild to severe conjunctivitis, ocular discharge, mild sneezing and nasal discharge.
The major alternative to vaccination is not vaccinating and treating any disease problems if they occur. As many of the diseases that we vaccinate cats against are viral, antibiotics are ineffective and treatment mainly involves supportive care.