Viremia = the virus is in the cat’s blood stream and saliva.
Thirty percent (30%) of cats exposed to the virus develop a persistent viremia. This means the virus remains in the blood and saliva for more than 12 weeks. The cat’s immune system fails to fight off the disease. The cats are susceptible to a range of fatal diseases. About 50% of these cats die within 6 months and 80% die within 3.5 years. So the lifespan of cats with FeLV when the virus overcomes the cat’s immune system is from 6 months to 3.5 years.
Of the remaining 70% of cats exposed to the virus, about 30% don’t develop an infection. While about 30% develop a transient viremia which means that the virus is present in blood and saliva for less than 12 weeks. The cats’ immune system fights off the disease and the cats are cured.
About 10% develop a latent infection. The cats’ immune system does not extinguish the virus completely. The virus remains in the bone marrow and in T-cell lymphocytes. The disease can eventually be fully extinguished but in some cats it comes back when stressed or the cat has another illness. These cats can develop fatal illnesses but the outcome is uncertain.