Feline Leukaemia Virus

Question 1

What type of virus is FeLV?

Answer 1

• gammaretrovirus
• member of the Orthoretrovirinae subfamily of retroviruses

Question 2

Survival of the virus

Answer 2

• doesn’t survive for long outside the host under dry conditions
• readily inactivated by disinfectants, soap, heating and drying
• transmission via fomites is very unlikely, but FeLV will retain infectivity and significant amounts of virus can survive for at least 48h if kept moist at room temperature

Question 3

Source of infection

Answer 3

• progressively infected cats are the main source of infection
• virus is shed in particularly high amounts in saliva, but also to some degree in nasal secretions, faeces and milk
• transmission occurs mainly via saliva through friendly contacts, like grooming, but also via aggressive interaction e.g. biting, and less frequently by sharing food bowls or litter boxes
• transplacental transmission and transmission through milk can occur
• transmission through blood transfusion is also possible
• kittens are most susceptible

Question 4

Risk factors for FeLV infection

Answer 4

• mixed-breed
• free ranging
• male intact
• living in multi-cat environments with 5+ cats
• originating from geographic areas with a high FeLV prevalence or from environments with progressively infected cats
• lack of FeLV vaccination

Question 5

What are the common FeLV-associated diseases associated with progressive infection

Answer 5

• tumours (esp lymphoma)
• bone marrow suppression (e.g. anaemia)
• immunosuppression leading to chronic or recurrent infections

Question 6

Prognosis

Answer 6

• cats with progressive FeLV infection has a decreased life expectancy, but they can be asymptomatic and have a good quality of life for many years
• cats with progressive FeLV infection and FeLV associated lymphoma or bone marrow suppression have a grave prognosis

Question 7

Advice for cats with FeLV

Answer 7

• strict indoors only lifestyle is the most important life-prolonging advice for progressively FeLV-infected cats to reduce exposure of the FeLV-infected cat to other infections
• cats with regressive FeLV infection should not be exposed to stress to avoid viral reactivation
• identifying FeLV infected cats along with vaccination is the mainstay of preventing further transmission