Feline Leukemia Virus Diagnosis

The feline leukemia virus (FeLV) is a serious infectious disease. It attacks and compromises a cat’s immune system and can cause an immuno-suppressive syndrome, cancer, and other diseases. Sometime the feline leukemia virus can lay dormant for years, while other viruses can attack swiftly.

The Feline Leukemia Virus Explained

The feline leukemia virus is the most common fatal disease in felines. This virus affects all breeds of cats, domestic and wild. Infected cats pass the virus through their urine, feces, bodily secretions, and saliva. The highest percentage of this killer disease occurs in kittens when the placenta of an infected mother passes the virus to her unborn kittens or through her milk while nursing.

There are three types of strains of the feline leukemia virus. FeLV-A compromises the immune system. FeLV-B is responsible for the development of tumors. FeLV-C is known to cause anemia. These strains are a type of retrovirus and cats can have one or a combination of these strains.

Feline Leukemia Virus Diagnosis

To diagnose the feline leukemia virus in a cat, a veterinarian will perform two different types of blood tests: the enzyme-linked immunoadsorbent assay (ELISA) and the immunofluorescence assay (IFA).

The ELISA test is the most simple of the two tests: the vet will draw blood, test for a color change, and see if antigens in the blood serum were detected. The ELISA test is commonly used, even though it’s known to read false positives, to detect the feline leukemia virus early in the course of infection, before it reaches the bone marrow and white blood cells. Interestingly, the ELISA test can look for feline leukemia antigens in a cat’s saliva and tears, but the results are not always reliable. Saliva and tears are often tested only when there are several cats to test at a time or when it’s difficult to obtain blood samples from a particular cat. If a kitten tested positive for the feline leukemia virus before the age of 16 weeks, it’s recommended he be retested after he’s 16-weeks-old to see if his mother’s antigens are out of his body.

The IFA test detects antigens in a cat’s white blood cells. If a cat tests positive for the feline leukemia virus using the IFA test, he should be retested to make sure the results weren’t a false positive due to the recent contraction to the virus.

Once the feline leukemia virus is in a cat’s bone marrow, either test will be able to confirm the presence of the feline leukemia virus. Curiously, research has shows that cats tested with ELISA can develop immunity to the virus, while cats tested with the IFA test are infected with the virus for the remainder of their lives.

The feline leukemia virus is malicious. Once diagnosed with this disease, a cat is contagious and is considered a carrier of the virus. To keep this virus contained, one should keep an infected cat away from other cats in a household. 80% of infected cats with the feline leukemia virus die within 3 years of contracting the illness.