What is Feline Leukemia?
Feline leukemia is a serious viral disease exclusively affecting cats, causing immunosuppression and increasing the risk of cancerous tumors. Cats living in groups or exposed to stray cats are especially vulnerable.
How is the Virus Transmitted?
The virus primarily spreads through saliva, tears, and urine, making mutual grooming and play common routes of transmission. Blood and placental transmission can also occur. Fortunately, the virus is sensitive to heat and disinfectants, limiting environmental contamination risks.
Disease Progression
After entering through the mouth or nasal cavities, the virus multiplies in the pharynx. Effective immune responses can quickly eliminate the infection. If unsuccessful, viremia (virus presence in the bloodstream) develops, spreading to lymphoid tissues.
At this stage, elimination is still possible if the immune system responds adequately. Otherwise, the virus infects bone marrow, white blood cells, and platelets, facilitating further spread. Some cats become latent carriers, potentially shedding the virus during stress or illness.
Symptoms of Feline Leukemia Virus
Symptoms vary based on disease progression. Initially, cats may exhibit fever, loss of appetite, and lethargy. As the disease advances, more severe symptoms appear, including weakness, anorexia, anemia, recurrent infections, weight loss, diarrhea, and nasal or ocular discharge. Specific symptoms depend on the organs involved.
Diagnosing the Disease
Diagnosis involves blood tests and complementary examinations. Blood analyses identify abnormalities linked to bone marrow infection. Urinalysis may detect opportunistic infections or abnormal protein presence. Thoracic radiographs can sometimes reveal masses or fluid accumulation.
Confirmatory Tests
Two serological tests confirm diagnosis:
- ELISA Test: Detects viral antigen in blood; positive 3-4 weeks post-infection.
- IFA Test: Identifies antigen in white blood cells and platelets; positive 8 weeks post-infection.
If both tests are positive, the cat remains viremic and a lifelong carrier. Discordant results require retesting after 2-3 months.
- PCR Test: Detects virus proteins even in small quantities in blood or bone marrow. Conducted externally, it confirms uncertain ELISA or IFA results. A delay is involved in obtaining results.
Disease Outcome
Disease progression varies among cats. Recovery is possible if bone marrow remains unaffected. Persistent blood infection leads to severe complications. Approximately 90% of viremic cats die within four years post-diagnosis, although many maintain good life quality during this period.
Is There a Treatment?
No curative treatment exists for feline leukemia. However, supportive care manages symptoms effectively. Chemotherapy is an option for lymphoma cases. Severe anemia may require blood transfusions. Unfortunately, treatment responses remain limited when severe complications arise.
Preventing Feline Leukemia Virus
Prevention relies on several critical measures:
- Limit cat outdoor access to minimize exposure risks.
- Vaccinate cats frequently exposed to potentially infected animals.
- Test all new cats before introducing them into multi-cat homes.
Implementing these strategies helps reduce feline leukemia transmission and improves affected cats’ quality of life.
