Feline Immunodeficiency Virus

Question 1

What does it cause?

Answer 1

immunodeficiency in cats, and therefore associated with a variety of lesions
• NOT zoonotic
LONG latent phase before onset clinical disease

Question 2

FIV epidemiology

Answer 2

• Domestic cats world-wide, generally <5% prevalence
• More common in males than females
• Most infected cats are >5 years old – long period between infection and disease
• More common in free-roaming, and feral cats and those living in unstable colonies - more contact with cats and increased fighting.
(FELV remember is different in that it is more stable friendly colonies of cats!)

Question 3

FIV transmission

Answer 3

FIV predominantly shed in saliva
• Mainly by biting
- Transplacental and milk transmission less common than FeLV
- Repro transmission possible but not common

Question 4

PAthogenesisi FIV

Answer 4

• Once infected with FIV – infected for life
Virus infects:
1. WBC - lymphocytes are targeted. Leading to progressive reduction in CD4 and CD4:CD8 population ratio
- CD4 T-cells, suppression leads to immunodeficiency
2. macrophages, kupffer cells
3. astrocytes
4. other cell types in cell culture (sometimes)
5. The virus gradually develops-
o decreased CD4, and CD4:CD8 ratios
o decreased mitogen and antigen proliferation assays
o decreased expression of MHC II
• But cats remain clinically healthy for 3-5 years, and perhaps for life.

Question 5

Clinical signs of FIV

Answer 5

Lesions due to immunodeficiency

1. chronic mouth infections
2. immune response isn’t functioning properly so see chronic forms of an infection

3. Enlarged lymph nodes.
Fever/ pyrexia
Anemia.
Weight loss.
Disheveled coat.
Poor appetite.
Diarrhea.

Question 6

Treatmetn FIV

Answer 6

supportive, usually normal life expectancy.

Question 7

Prevention and control

Answer 7

•	Identify infected cats
•	Vaccination
•	Prevent cats fighting – keep indoors/neuter
•	Isolate infected cats
•	Neuter so less aggressive
Vaccination not an option in UK

Question 8

Why vaccine not option in UK but is licensed product in US

Answer 8

questions about efficacy

FIV so variable so protection may not translate to field

Question 9

If queen positive to FIV, how does this affect the kittens?

Answer 9

1. queen passes antibodies to kittens via MDA
2. kittens antibody positive
3. most don’t actually get virus
4. test tests for Ab so if kittens test positive retest in 6 months

Question 10

What would you do with an FIV + 6-week-old kitten?

Answer 10

1. likely from FIV positive queen
2. If tested at 6 weeks and positive for Ab, almost 100% certain MDA which last for up to 9 weeks
3. REcommend retest at 12 weeks, if positive wait 6 months incase MDA last this long adn retest
4. If positive again, isolate for life

Question 11

What would you do with an FeLV + 1-year-old clinically normal cat?

Answer 11

Retest

positive again then isolate for life

Question 12

How long post infection with FIV does it take for FIV antibody to be produced?

Answer 12

After FIV infection, it takes 3 weeks for anti-FIV Ab to be produced.