DM2 Pt1-2 Feline Leukaemia Virus (FeLV)

Question 1

What is Feline Leukaemia Virus (FeLV)?

Answer 1

FeLV is a retrovirus that can cause immune suppression, anaemia, and lymphoma in cats.

Question 2

How has the prevalence of FeLV changed in recent years?

Answer 2

The prevalence of FeLV has decreased significantly due to reliable testing and effective vaccines.

Question 3

How is FeLV transmitted between cats?

Answer 3

FeLV is transmitted primarily through friendly contact (e.g. grooming) and also through biting.

Question 4

What percentage of cats in large non-vaccinated groups develop persistent viraemia?

Answer 4

About 30-40% of cats in large non-vaccinated groups develop persistent viraemia.

Question 5

What are the risk factors for FeLV infection?

Answer 5

Young age, high population density, and poor hygiene increase the risk of FeLV infection.

Question 6

What are common clinical signs of persistent FeLV viraemia?

Answer 6

Common signs include immune suppression, anaemia, and lymphoma.

Question 7

What are less common signs of FeLV infection?

Answer 7

Less common signs include immune-mediated disease, chronic enteritis, reproductive disorders, and peripheral neuropathies.

Question 8

How long do most persistently viraemic cats live?

Answer 8

Most persistently viraemic cats die within 2-3 years of diagnosis.

Question 9

Where is FeLV shed in infected cats?

Answer 9

FeLV is shed in saliva, nasal secretions, faeces, and milk.

Question 10

What percentage of cats in large non-vaccinated groups show transient viraemia or seroconversion?

Answer 10

Around 30-40% of cats show transient viraemia, while 20-30% seroconvert.

Question 11

What are the four possible outcomes of FeLV infection?

Answer 11

1) Persistent infection, 2) Transient infection (virus eliminated), 3) Latent infection (virus persists in tissues), and 4) Focal infection (rare).

Question 12

What is the main method used for diagnosing FeLV?

Answer 12

Diagnosis is based on detecting free p27 antigen using ELISA or ICA tests.

Question 13

When do antigen tests for FeLV become positive?

Answer 13

These tests become positive during the primary viraemic phase, within a few weeks of FeLV infection.

Question 14

Why is it important to confirm positive FeLV antigen results?

Answer 14

A positive result can be due to persistent or transient infection or a false positive, so confirmation is needed, especially in healthy cats.

Question 15

What can a negative FeLV antigen result indicate?

Answer 15

A negative result can mean no exposure, successful elimination of the virus, recent infection, or latent/localised infection.

Question 16

What additional tests are recommended for FeLV-positive cats?

Answer 16

Immunofluorescent antibody testing (IFA) or PCR should be used to confirm the infection or detect latent or localized infections.

Question 17

What does a positive IFA test indicate in FeLV-positive cats?

Answer 17

A positive IFA test indicates bone marrow infection and usually persistent viraemia.

Question 18

How does PCR testing aid in diagnosing FeLV?

Answer 18

PCR detects FeLV proviral DNA, which helps identify latent, persistent, or recovered infections.

Question 19

What should be done if discordant test results are encountered?

Answer 19

Repeat testing and continued monitoring are recommended to clarify discordant results, especially in clinically healthy cats.

Question 20

What should be done if FeLV infection is confirmed?

Answer 20

Further investigations, including haematology, biochemistry, urinalysis, and imaging, should be performed to assess for FeLV-related diseases and concurrent infections.

Question 21

What can protect susceptible kittens from FeLV infection?

Answer 21

High-titred antisera injections can protect susceptible kittens from FeLV infection.

Question 22

Why is treatment with monoclonal antibodies to FeLV ineffective once persistent viraemia is established?

Answer 22

Once persistent viraemia is established, neutralising monoclonal antibodies are ineffective.

Question 23

What type of immunity do cats that have overcome FeLV viraemia typically possess?

Answer 23

They usually have high titres of antibodies and are resistant to future FeLV infection.

Question 24

Is FeLV vaccination considered a core vaccine for cats?

Answer 24

No, FeLV is a non-core vaccine, but recommended for routine immunization in most cases.

Question 25

Why might indoor cats have a lower risk of FeLV infection?

Answer 25

Indoor cats are at lower risk if all individuals in the home are FeLV-negative.

Question 26

At what age should kittens receive their first FeLV vaccination?

Answer 26

Kittens should be vaccinated at 8-9 weeks and again at 12 weeks.

Question 27

Why should kittens receive a booster FeLV vaccination at 12 months?

Answer 27

Kittens should receive a booster because their future lifestyle (outdoor access) is uncertain.

Question 28

What are the differences in FeLV vaccine formulations?

Answer 28

Some vaccines use virus vectors like Canary Pox for stronger immune responses; others use whole or parts of the virus (recombinant p45/gp70).

Question 29

Why is FeLV testing recommended before vaccination if the FeLV status of the cat is unknown?

Answer 29

Testing prevents ‘vaccine failures’ where already infected cats develop FeLV-related clinical signs.

Question 30

When is FeLV testing before vaccination unnecessary?

Answer 30

Testing may be unnecessary for kittens from FeLV-negative parents with no contact with other cats.

Question 31

How often are booster vaccinations for FeLV recommended after the primary course?

Answer 31

Most vaccine producers recommend annual boosters, though boosters every 2-3 years may be sufficient for adult cats older than 3-4 years.

Question 32

Why should FeLV-negative cats in multi-cat households be regularly re-tested?

Answer 32

FeLV vaccination is not 100% effective, so negative cats living with FeLV-positive cats are at risk.

Question 33

What should be done with resources in multi-cat households containing FeLV-positive cats?

Answer 33

Resources should be separated to reduce the risk of transmission.

Question 34

What is the recommendation for sick FeLV-positive shelter cats?

Answer 34

Sick FeLV-positive cats in shelters should be euthanized.

Question 35

How can confirmed FeLV-positive healthy cats be adopted from shelters?

Answer 35

They should be adopted by households where they pose no risk to uninfected cats, ideally in isolation or with other infected cats.

Question 36

What should be done to minimize FeLV transmission in shelters?

Answer 36

Cats should be housed individually, or if housed in groups, tested and segregated by FeLV status.

Question 37

Why is routine testing recommended in pedigree breeding catteries?

Answer 37

Routine testing helps maintain the low prevalence of FeLV infection and should be done once or twice a year.

Question 38

What treatments are used for FeLV-infected cats to reduce the effects of the virus?

Answer 38

AZT and feline recombinant interferon are used, but their efficacy is controversial.

Question 39

How can secondary infections be prevented in FeLV-infected cats?

Answer 39

Prevent secondary infections by avoiding raw meat, regular flea and worm treatments, providing a good diet, and keeping the cat indoors.

Question 40

What is important when managing FeLV-infected cats housed with other cats?

Answer 40

Regular vaccination using killed vaccines is important if housed with other cats.

Question 41

What should be done to reduce the risk of FeLV infection to other cats in the household?

Answer 41

Maintain a stable group, don’t introduce new cats, thoroughly clean food bowls, discourage sharing, and vaccinate in-contact cats.

Question 42

Why should FeLV-positive cats be kept indoors in densely populated cat areas?

Answer 42

Keeping FeLV-positive cats indoors reduces the risk of spreading the virus to other cats.