Cats: We vaccinate all cats with an F3 vaccine, and additionally the FIV vaccine for cats that go outdoors.
Feline herpesvirus. The most common cause of cat ‘flu. Most cats are exposed to this virus at some stage of their lives. Similar to the herpesvirus causing cold sores in humans, once infected cats cannot eliminate the virus from their bodies. The virus causes sneezing, nasal infections, fever, conjunctivitis and ulcers on the surface of the eyes. More rarely it can affect the lungs causing a potentially life-threatening pneumonia. Most cats will recover from this initial infection, but the virus remains dormant in nerve endings and can periodically re-activate through the cats life causing further bouts of ‘flu. A small number of cats never recover from the initial infection and generally don’t do well as a result.
Feline calicivirus. Another cause of cat ‘flu. The virus causes upper respiratory signs similar to herpesvirus, but can also cause erosive ulcers in the mouth and in joint tissue. Cats will frequently become chronic carriers and shedders of the virus after recovery from the initial infection, acting as sources of infection for other cats despite appearing perfectly healthy. The virus can survive in the environment for extended periods and is quite resistant to a number of disinfectants. The virus mutates rapidly and occasionally highly virulent strains emerge that can cause devastating disease, whereas other strains are much more benign.
Panleukopaenia (feline parvovirus). Similar to canine parvovirus (in fact the canine virus mutated from the feline virus originally), this is a frequently fatal infection. Most cats are exposed to this virus during their lifetime. The virus infects rapidly dividing cells causing severe gastrointestinal signs of vomiting and diarrhoea, and destruction of lymphoid tissue and bone marrow. The cat’s white blood cell counts are decimated by the virus replicating in bone marrow, leading to immunosuppression. This inability to fight off infection frequently causes fatal secondary infections with other bacteria and viruses. The virus can survive in the environment for long periods of time.
FIV (feline AIDS). This virus is in the same family as the human HIV/AIDs virus (retroviruses) and causes a similar disease syndrome. They cannot be transmitted between the two species (cats cannot be infected with human HIV or vice versa). It is usually spread by cat bites during the course of cat fights, hence why we vaccinate cats with outdoor access against this virus. Studies have shown the virus is prevalent in approximately 20% of the feral cat population. Once infected there is no effective treatment for the virus. Following infection the virus causes a short-lasting fever. The cat will then usually go into a longer asymptomatic period where there is no sign of disease at all. This phase can last for many years. At some stage they will typically then develop AIDS (immunodeficiency) due to loss of lymphocytes (a type of white blood cell) and the cat will develop frequent infections (such as bladder or skin infections) which can be difficult to eliminate.