Leukemia in Cats

Feline leukemia virus (FeLV), a retrovirus, is a leading cause of feline mortality. If detected in the early stages, the outlook is positive for eliminating the virus. The prognosis is poor in the case of recurrence or if the virus reaches advanced stages before detection.

Feline leukemia virus (FeLV), is second only to accidents as the leading cause of death for cats. The good news is that most healthy cats can resist and eliminate the virus when infected, if treated early. A vaccine for FeLV is available and commonly offered by your veterinarian as a part of routine immunizations. FeLV suppresses the cat’s immune system and can lead to additional infections. Anemia or lymphoma are also possible complications of contracting FeLV.

During the early stages of FeLV, your cat may not exhibit any specific symptoms.You may notice a progressive deterioration of your cat’s health or periods of relatively good health intermingled with periods of poor health. Symptoms of FeLV may include:

• Loss of appetite
• Weight loss
• Persistent fever
• Pale or inflamed gums
• Eye conditions
• Poor condition of coat
• Diarrhea
• Seizures
• Changes in behavior
• Yellow color in mouth or whites of eyes
• Trouble breathing
• Bladder or skin infections
• Progressive weakness
• Reproductive problems in unspayed females

FeLV is a retrovirus that is transmitted from cat to cat through saliva, tears, urine, feces or mother’s milk. Transmission of the virus occurs only from cat to cat. Other family pets or human family members are not at risk of contracting the virus from your cat. Common means of transmission of the virus include:

• Grooming 
• Fighting
• Biting/wounds/scratches
• Shared litter boxes
• Mother to kitten transmission in utero or through nursing

Your veterinarian will complete a thorough examination of your cat. The sooner your cat begins treatment, the better. Be prepared to share information regarding when you first noticed symptoms, the symptoms you noticed and if any changes have occurred. 

A blood test, known as ELISA, will be administered to identify leukemia proteins in the blood. This test is highly sensitive in detecting early infections. In the early stages of FeLV, the cat’s immune system may be able to fight off the virus and eliminate the infection. If initial ELISA testing is positive, an additional test should be completed as confirmation.

An additional blood test, Immunofluorescent Antibody (IFA), may be necessary. The IFA test detects the progression of the infection. A positive IFA result means the disease has advanced. 

Another test that may be used to further investigate the possibility or advancement of FeLV is a polymerase chain (PCR) test.

FeLV infection generally falls into three categories: 

• Healthy cats with good immune systems can often fight off the infection.
• Some cats will not be able to rid themselves of all of the infection and will continue to have a latent infection, which may or may not become active.
• A persistently infected cat will exhibit no effective immune response to the infection.

If your cat tests positive for FeLV, your veterinarian will treat him according to the level of infection. Your vet may recommended supportive care, such as fluids and nutritional therapy. Antibiotics to treat secondary infections may be prescribed. In severe cases, antiviral drugs or chemotherapy may be recommended.

Keep in mind that no test is 100% accurate. If it is highly likely that your cat was exposed to FeLV, but ELISA testing showed a negative result, the cat should be retested in 30 days. If the ELISA testing is positive, but the IFA is negative, your cat should be retested in 60 days. 

The best treatment for FeLV is prevention. The American Association of Feline Practitioners (AAFP) recommends FeLV screening for all cats. Any cat that comes in contact with other cats other than those in their immediate family should be screened. Any cat that goes outdoors, stays in a boarding facility or participates in shows should be screened and vaccinated against FeLV. 

Recovery depends on the degree of infection. Cats who are positive for FeLV should receive regular veterinary check-ups to prevent further infection and manage the stages of the disease. Your cat should be kept indoors and neutered or spayed. Contact your veterinarian to address any suspected secondary infections as soon as possible.

• A single cat home is the best environment for a FeLV positive cat.
• Feed your cat a high-quality food. 
• Give your cat vitamin supplements. 
• Keep your cat’s nails clipped and smooth to avoid scratches.
• Monitor your cat’s temperature, if elevated (over 102.4⁰f), contact your veterinarian.
• Do not give your cat raw foods.

While there is no cure for cat leukemia, your pet can live a good quality life with proper care and follow-up with your veterinarian. The majority of cats who test positive for FeLV live about three years after infection.