Most cat vaccinations aim to prevent at least three diseases in kittens and cats: Feline Panleukopaenia Virus, Feline Herpesvirus 1 and Feline Calicivirus.
Feline Panleukopenia Virus (FPV), also called Feline Distemper or Feline Enteritis, is a highly contagious virus of the parvovirus group, with a high mortality rate, especially in younger cats. It is extremely hardy and may survive for months and years. It is easily transmitted through contact, either from cat-to-cat or by human-to-cat. Transmission can occur via feeding equipment, litter trays, bedding, fleas (active stage), from an infected pregnant cat to her unborn kittens and by contact through hands, clothing and shoes. Within 24 hours of infection, the virus is present in the blood, which distributes it throughout the body. Within two days of infection, nearly everybody tissue contains significant amounts of the virus. Feline Panleukopenia is characterised by sudden onset, fever, loss of appetite, dehydration, depression, vomiting, a hunched postural appearance and decreased numbers of circulating white blood cells (leukopenia).
Treatment involves alleviating vomiting and diarrhoea to prevent subsequent dehydration, along with steps to prevent secondary bacterial infections, until the cat’s natural immune system takes over. It is possible for kittens to receive immunity through the transfer of antibodies via the mother’s first milk (colostrum), but it is rarely effective in kittens older than 12 weeks. Vaccines offer the safest protection as they stimulate the cat’s body to produce protective antibodies to prevent future infections.
Feline Herpesvirus 1 (FHV1) can cause serious harm, especially in kittens. It has been estimated that 50-60% of very young kittens with severe Feline Herpesvirus 1 infections will die, with the virus causing permanent neurological damage.
Feline Herpesvirus 1 and Feline Calicivirus are also the most common cause of Feline Respiratory Disease (FRD), often called cat flu or cat snuffles. The most common symptoms of FRD are sneezing, discharge from the eyes and/or nose and loss of appetite. FRD is spread in a similar way to Feline Panleukopenia Virus. When cats are infected with the virus, they do not always show signs of illness, but can still be infectious to other cats, sometimes becoming ‘carriers’ of the disease. Carrier cats are the main reason for the spread of Feline Herpesvirus 1 and Feline Calicivirus in our cat population. These cats will start to shed the virus in times of stress, much like the situation that occurs with cold sores in people: the disease appears at times of stress then gets better, then returns after the next stress episode. Stress factors can include illness or trauma, change of home, breeding, travelling, attending cat shows, house renovations, or a new person or pet in the household.
Most cat vaccinations are a combination of the vaccines against the three viruses mentioned above. The vaccines are effective but are preventive, not curative. They reduce the severity of the disease and the amount of virus shed. Vaccinations must be given before the cat is exposed and infected.
Most young kittens receive their first vaccination from eight weeks of age, with follow-up vaccines every 3-4 weeks until the kitten is more than 12 weeks of age, then booster vaccinations every one to two years, dependant on age, vaccine and the kitten’s level of social contact. It is also important to remember that when your cat is vaccinated, it takes time for its immune system to make the necessary antibodies needed to fight these diseases. The process is not immediate and can take up to 10 days to complete, hence the need to wait 10 days between vaccination and exposure to any risk such as mixing with other cats or going to a cattery. Also, if your cat doesn’t receive all recommended booster vaccinations at the correct time, he or she will not be fully vaccinated and will still be at risk of developing these diseases in the future.