Feline Leukemia Virus (FeLV)

Feline Leukemia Virus (FeLV) is one of the most common and destructive of all cat viruses. It is highly contagious and is spread primarily by saliva during cat fights, grooming or mating. Blood, urine, and feces also spread this virus. Kittens may become infected while still in the womb, when the mother bites off the umbilical cord or during nursing. The act of sharing the same food dish or litter box can also transmit the virus. Not all cats exposed to FeLV become infected. About 33% of exposed cats have immune systems that can destroy the invading virus. The remainder of exposed cats becomes persistently infected (33%) or develop a latent infection (33%). The latter group has inactive virus in their bone marrow which may later become active when the cat becomes ill from another disease, stress or certain drugs. Of the cats persistently infected about 25% will die within one year and 75% will die within 3 years. Some may live a normal life but tend to have various chronic illnesses.


There are no signs specific for FeLV infection. The main effect of the virus is to disrupt the cat’s immune system. While anemia is the most common disorder caused by the virus, cancer and various other diseases are commonly associated with FeLV. Disorders commonly associated with FeLV

infection include chronic respiratory disease, chronic infection of the mouth, gums, and tongue, chronic eye disease, frequent or chronic skin disease, reproductive disease (abortion, stillbirths, and kitten deaths), frequent or chronic urinary tract infections, chronic digestive tract disease and other systemic diseases (infectious peritonitis, hemobartonellosis, toxoplasmosis, polyarthritis, etc).


Vaccination before exposure to the virus is the best means of preventing FeLV infection. Without vaccination, isolation from other cast is the only means of prevention.

Important Facts:

• Infected cats are at high risk for developing cancer or other life-threatening diseases.

• Indoor cats are at moderate risk for aquiring FeLV infection

• Outdoor cats are at high risk for aquiring FeLV infection

• Currently there is no uniformly effective treatment for cats infected with FeLV

• Ask your Veterinarian to test any new cat or kitten before bringing it into your household

Feline Immunodeficiency Virus (FIV)

Feline immunodeficiency virus (FIV) affects the cat’s immune system much the same way HIV affects humans. Therefore, it is often called feline AIDS. The disease causes the cat’s immune system to weaken, making it more vulnerable to other infections. There is no evidence to suggest that FIV can be transmitted from cats to humans or other animals. Leading veterinary researchers believe that FIV is most commonly transmitted through bite wounds. Adults, free-roaming male cats are at the highest risk for FIV because they tend to fight with other cats.

Several studies have been conducted to understand the prevalence of FIV. Research to date suggests that 10-20% of sick cats carry the virus. Among the high risk cat population (outdoor cats or cats exposed to outdoor cats) the infection rate is estimated to be around 5%.


The infection occurs in 2 stages. During the initial phase of the disease many FIV-infected cats appear healthy. Therefore, many cats go through Stage 1 with the disease unnoticed by their owners. Generally, problems are not detected until Stage 2 when the immune system weakens and other infections occur. Many of these symptoms are common with other disease such as Feline Leukemia Virus (FeLV). Common signs of Stage 1 of the disease include enlargement of lymph nodes, fever, poor coat condition, and lethargy. Stage 2 signs consist of loss of appetite, weight loss, persistent diarrhea, oral lesions or sores, and skin, urinary and upper respiratory infections. Diagnosis is made based on a cat’s history, clinical signs, and results from a FIV antibody test. Both in-clinic and laboratory tests are available. A positive test result indicates that a cat is infected with FIV and could transmit the virus to other cats. Once a cat is infected with FIV the cat is infected for life.


Currently no cure exists for the cats that have contracted the disease. In general, veterinarians recommend that pet owners confine FIV-positive cats indoors to reduce the chance of transmitting the disease to other cats and to limit cat’s exposure to infection. Neutering is also be recommended to reduce the urge to roam and fight. Regular veterinary check-ups should be scheduled to monitor the cat’s condition and to treat any secondary infections as quickly as possible. In addition, pet owners should provide the cat with a healthy diet, plenty of fresh water, and a stress free environment. Finally, treating the cat routinely with anti-parasitic medication is indicated due to being immuno-suppressed.


• Keep your cats indoors

• Neuter male cats to reduce the urge to roam and fight

• Ask your veterinarian to test any new cat or kitten before bringing it into your household.