FELINE LEUKEMIA VIRUS (FeLV)

The feline leukemia virus (FeLV), or feline leukemia, is a highly contagious viral illness that may compromise a cat’s ability to fight off other illnesses and increase the likelihood of a variety of potentially life-threatening conditions such as anemia, chronic infections and some forms of cancer. FeLV is considered to be one of the top infectious diseases threatening cats globally and has a major effect on a cat’s long-term health.

The primary method by which a cat becomes infected with FeLV is through direct contact with another cat that carries the disease. This makes outdoor cats and those who live in multi-cat homes much more likely to contract this illness.

There is no cure available to treat feline leukemia; however, if diagnosed early, support for the cat and vaccinations for healthy cats will aid in managing symptoms and reducing the transmission rate of the virus.

Causes

FeLV is caused by a retrovirus that can infect immune cells, bone marrow cells and other tissues.

These areas of the body are vital for fighting off infections. When these areas become damaged due to FelV, the cat becomes increasingly susceptible to contracting other illnesses.

How the Virus Spreads

Saliva is the main vehicle used by FeLV to move from cat to cat. Cats contract FelV when they come into direct contact with another cat that carries this virus. Direct contact can through prolonged close contact such as mutual grooming and sharing food or water bowls.

Infected mother cats can also transmit the virus to their kittens while they are developing inside the womb (while pregnant) or after birth through nursing.

Risk Factors

Several factors will increase the likelihood of a cat developing FeLV; these include:

• Living with FeLV-positive cats
• Frequent outdoor activities
• Bite wounds from infected cats
• Multi-cat household
• Young kittens, as they are generally more susceptible to the disease than older cats

Symptoms

• Loss of appetite
• Weight loss
• Lethargy
• Persistent fever
• Pale gums caused by anemia
• Enlarged lymph nodes
• Recurrent respiratory or skin infections
• Poor coat condition
• Diarrhea or vomiting
• Difficulty healing from minor illnesses

Risks and Complications

FeLV compromises many different systems within your cat’s body and causes numerous severe health issues over time.

Due to its immunosuppressive effects, it makes cats more susceptible to secondary infections caused by bacteria, viruses and fungi that healthy cats are able to fight off. Bone marrow suppression from the virus may cause your cat to have anemia along with decreased ability to produce red/white blood cells.

A major complication of this infection is the elevated risk of developing lymphoma or leukemia. Cats may also develop chronic renal failure, reproductive issues, or central nervous system disorders as their FeLV infection progresses.

As the weakened immune system continues to decline, the potential of even minor infections becoming fatal will increase if they go untreated.

Diagnosis

FeLV can be identified through blood testing. Your veterinarian will likely test your new cat, your cat when ill or your cat that has come into contact with another cat who is positive for the virus. The most commonly used screening test is the ELISA blood test, which identifies the presence of the virus in the initial stages of the infection. If you receive a positive diagnosis using this method, then further confirmation testing, including IFA (Immunofluorescence Antibody) testing or PCR testing, may be warranted.

Your veterinarian may use blood tests, urinalysis and radiography/diagnostic imaging to assess the overall status of your cat’s health. Other cats in the household should be tested for FeLV exposure.

You may need to retake a series of blood tests at various intervals depending upon how long ago your cat was exposed to the virus.

Treatment

Currently, there are no treatments available for the eradication of FeLV. The goal is to manage complications, support overall health and maintain quality of life.

Supportive Care

The cornerstone of supportive care includes the provision of good nutrition, appropriate management of secondary infections, parasite control and routine veterinary follow-up. It has been shown that many FeLV-positive cats can have long-term comfort when provided with adequate care.

Managing Secondary Illnesses

Cats that develop FeLV will likely need to receive antibiotics, fluids, nutritional support, blood transfusions, or stimulants to promote eating when needed. Chemotherapy may be used to treat lymphoma, which develops in some cats with FeLV, to enhance the quality of their lives and prolong their survival.

Prevention

One of the best methods of reducing the risk of FeLV infection in cats that may be exposed to it is vaccination. FeLV-positive cats should ideally be housed separately from FeLV-negative cats to prevent transmission.

Providing indoor environments for all cats is a highly effective method of preventing exposure to FeLV by either direct contact with an infected animal during combat or through close contact with an infected animal. Routine veterinary exams and regular testing for those at risk help to detect infections early and prevent them from spreading