FeLV

FELINE LEUKEMIA VIRUS (FeLV) 

• Reservoir [confirmed]

  • Felines

• Portal of exit [confirmed]

  • viral particles are contained in infectious cats' saliva, feces, urine and milk.

• Mode of transmission  [confirmed]

  • any close contact among cats, such as contact of an infected mother with her kittens either transplacental or transmammary, as well as fighting, grooming, shared feeding dishes, or a shared litter box.

• Portal of entry [confirmed]

  • Feline Leukemia Virus is a retrovirus that is incorporated into its host genome. Infectious viral particles can be transmitted to the new host in a manner similar to how they exited their previous host. They can enter via blood, saliva, and milk. Portals of entry include oral, mucous membranes, and blood. 

• Susceptible host [confirmed]

  • Once exposed to FeLV, the cat's body can respond in one of three ways. 

    • An Abortive Infection occurs when the infected cat's immune system is able to mount a successful immune system response and completely eliminate the virus.

    • A Regressive Infection occurs when the infected cat's immune system is able to mount a partially successful immune system response. This results with the immune system preventing prolonged periods of viral replication. In this instance the virus is still contained within the bone marrow and may potentially reactivate at some point in the future, causing the cat to become a source of infection. This infection usually does not result in any clinical signs of the disease.

    • A Progressive Infection occurs when the cat’s immune system is unable to mount a successful response to the virus and both the blood and the bone marrow of the host is infected, allowing the virus to replicate. This results with the host serving as an active source of infection for other cats. This cat may also begin to show clinical signs of the disease. 

• Clinical signs [confirmed; but also inflammation of gums and stomach, behavior changes and neurological disorders, variety of eye disorders]

  • Loss of appetite

  • Progressive weight loss

  • Poor coat condition 

  • Enlarged lymph nodes

  • Persistent fever

  • Anemia 

  • Comorbid infections

  • Persistent diarrhea

  • Seizures

  • Abortion of kittens and other reproductive failure 

• Prevention [confirmed; additionaly keep cats indoors and if inside cats are allowed outdoors to make sure to supervise or keep in secure environment, FeLV testing to cats before being introduced into a new home]

  • Vaccinations for FeLV are available, although they are not 100% effective. 

  • Recommendations to reduce risk of infection include reducing exposure to potentially infected cats. 

Sources: [confirmed]

• “Feline Leukemia Virus.” Cornell University College of Veterinary Medicine, www.vet.cornell.edu/departments/cornell-feline-health-center/health-information/feline-health-topics/feline-leukemia-virus.

• St Denis, Kelly A. “Feline Leukemia Virus Disease.” Merck Veterinary Manual, 10 Feb. 2022, www.merckvetmanual.com/generalized-conditions/feline-leukemia-virus/feline-leukemia-virus-disease#Diagnosis_v3276581.

• • Reviewed by Keira Delp