Feline Leukemia(FeLv) is one of two diseases we routinely screen for in new kittens and outdoor cats, with the other disease being Feline Immunodeficiency Virus(Fiv)or Aids. Thankfully, we are not seeing this disease too often due to diligent vaccinating and routine screening.

FeLv is caused by a C-type retrovirus or oncornavirus that has a propensity to cause cancer of lymphoid cells and bone marrow stem cells. FeLv is spread by carriers in the saliva (richest source), urine and feces. Thus biting and intimate contact (mutual grooming/oral contact) is a very common mode of transmission. FeLv may also be passed in utero (transplacental) from mother to fetus, however most kittens die at birth. Survivors may mount an immune response and overthrow the virus resulting in a cure, become a carrier (10%) or have active disease.

The primary stage of illness has varying severity and may last several weeks. One may see enlarged lymph nodes and low grade fever. Two to four weeks after infection, anemia and low platelets may be seen. In 70-90%, the patient’s immune system will overthrow the virus and fully recover. Others will become carriers and continue to worsen. In carriers, the virus will cause cancer (lymphoma, blood related cancer etc), anemia (1/3 to 1/2 of patients develop severe anemia) and immunodeficiency (simple infections can cause severe disease and/or death). The average lifespan of a FeLv carriers is 1/2 to 1 year. Cats with active disease will usually die from a common respiratory infection or “cold” due to a poor immune system caused by the virus.

Diagnosis is accurate, simple and takes 10 minutes. Currently we use the Idexx Snap test which utilizes a few drops of blood. It also screens for Fiv or Aids.

Prevention is always better than treatment. Several commercially available vaccines are available and are very effective. Two vaccines are required initially 3 weeks apart and then once yearly thereafter.

This is a very serious and lethal disease. Some pets can live fairly normal lives, but will eventually die from the virus or illness caused by the virus. Early testing and proper vaccinating is key to hopefully someday eradicating this disease.

As always, please feel free to contact the clinic if you need further information regarding Feline Leukemia.