Feline Leukemia Virus (FeLV)
Feline leukemia virus can cause a multitude of disorders, including tumors, bone marrow and immune system suppression, weight loss, chronic infections and anemia. Some cats don’t develop symptoms for several years after they become infected. FeLV vaccines are not completely protective in all cases, but they may reduce the severity and duration of clinical disease. FeLV vaccines may be recommended for cats entering a household with a cat known to be infected with the virus. They also may be appropriate for cats that travel to shows, spend time outdoors or live in multi-cat households, where they have a heightened chance of being exposed to cats of unknown viral status. Most veterinarians recommend testing a cat to determine its FeLV status before administering a FeLV vaccine. This vaccine usually is given twice, 2 to 3 weeks apart, followed by annual boosters.
Feline Immunodeficiency Virus (FIV, “Feline AIDS”)
The feline immunodeficiency virus is extremely contagious. It is transmitted by direct cat-to-cat contact, which often occurs through bites during a cat fight. FIV is related to the human AIDS virus (human immunodeficiency virus, or HIV), but fortunately cross-infection between species apparently does not occur. Cats infected with FIV typically experience a gradual reduction in immune system function, which predisposes them to developing chronic infections of all sorts. As with human HIV, there is no known cure for FIV infection in cats. Preventing FIV negative cats from being exposed to FIV positive cats is the best way to avoid disease. The FIV vaccine can support this effort, but it does not provide complete protection. Moreover, a cat given the FIV vaccine will test positive for FIV, when in fact it is not infected with the virus. Outdoor cats that are prone to fighting with other cats or that frequently come into close contact with cats of unknown FIV status may benefit from the vaccine. The risks and benefits of vaccinating against FIV should be discussed with a veterinarian.
The Bordetella bronchiseptica bacterium causes severe respiratory tract disease, especially in young kittens. It is extremely contagious. Signs of Bordetellosis include coughing, nasal and ocular (eye) discharge, fever, lethargy and weakness. Cats that may come into contact with infected cats, such as in shelters and multi-cat households, as well as cats that travel to shows or are exposed to free-roaming feral cats, may be good candidates for vaccination. The disease typically responds readily to antibiotic treatment, so routine vaccination generally is not recommended.
Chlamydia (formerly Chlamydia, now Chlamydophila Felis)
Chlamydophila felis is an organism that infects the eyes and respiratory tract of cats, causing a condition called “feline pneumonitis.” The vaccine against this organism typically reduces clinical signs and shortens the course of the disease, but does not protect against infection. Antibiotic treatment is usually quite effective in controlling symptoms of and resolving Chlamydophila infection.
Feline Infectious Peritonitis (FIP, Coronavirus)
FIP is caused by a feline coronavirus. It is transmitted between cats primarily by the fecal-oral route, when uninfected cats come into contact with the feces of infected cats. Many cats are infected with coronavirus, but few actually develop disease. The efficacy of the FIP vaccine is controversial, and the duration of any immunity that it may provide is short. Most veterinarians do not routinely recommend this vaccine. Occasionally, it is used for uninfected cats living in an environment where FIP-positive cats are present, such as in large catteries with endemic infections.
This single-celled protozoan parasite of the gut, formerly called Giardia lamblia, is now known as Giardia intestinalis or Giardia duodenalis. Giardiasis causes bloating, diarrhea, gas and rancid, foul-smelling feces that typically are soft, watery, bloody and filled with mucus. Some infected cats don’t show clinical signs and appear relatively normal. Current protocol is not to vaccinate cats against Giardia. The infection is easy to treat, and the effectiveness of the vaccine is questionable.
Ringworm has nothing to do with worms. It is a plant-like growth that infects outer layers of skin and hair follicles and fibers. It is caused by one of a number of fungal organisms, known as “dermatophytes.” Ringworm gets its name from the round, raised, red, scaly areas of hair loss and inflammation caused by the superficial fungal infection. Domestic dogs and cats usually “get ringworm” from Microsporum canis. Occasionally, the infection is caused by Microsporum gypseum or Microsporum mentagrophytes. Many cats are carriers of these infective fungi and shed infective fungal spores, which are extremely resistant to temperature and weather conditions. These spores contaminate the environment and become the source of infection to other animals. Ringworm infection (“dermatophytosis”) causes almost no harm to infected animals. However, it is highly contagious, and it can be spread to people. Children are especially susceptible. The ringworm vaccine may reduce the severity of symptoms, but it is not reliably effective in preventing infection.