Feline Immunodeficiency Virus (FIV)

Question 1

What type of virus causes FIV?

Answer 1

RNA retrovirus

Question 2

What is the geographic distribution for FIV?

Answer 2

Worldwide

Question 3

Who is the poster child for FIV?

Answer 3

Older (>6 years old), outdoor (feral), male cats

Question 4

How do cats get FIV?

Answer 4

• Bites (fights)
• Milk (FIV + queens to kittens)
• Transplacental

Question 5

What are the initial (1st viremia phase) signs of FIV?

Answer 5

• Mild fever
• Lymphadenopathy
• Not well for a few days then get better

Question 6

How long does the subclinical (latent) period last?

Answer 6

• Average 7 years
• Duration depends on: strain and age when infected (viral load)
• Test for ANTIBODIES (if you have clinical signs, you WILL have antibodies)

Question 7

What are the clinical syndromes in an FIV patient?

Answer 7

• Chronic small bowel diarrhea
• Hematologic changes (NR anemia, thrombocytopenia, neutropenia, myeloproliferative disease)
• Anterior uveitis

Also glomerulonephritis, renal failure, secondary infection (immunosuppressive; stomatitis), and CNS signs (young cats)

Question 8

What lab changes will you see in an FIV positive cat?

Answer 8

Non-specific

• Pancytopenia
  
  • Non-regenerative anemia
  • Thrombocytopenia
  • Neutropenia
• Myelodysplasia or leukemia
• Polyclonal gammopathy

Question 9

Who should be tested for FIV?

Answer 9

Every sick cat

Question 10

How do you diagnose a cat with FIV?

Answer 10

Serology (seroconversion takes 2-4 weeks; maternal antibodies last 14 weeks, retest + kittens at 8-12 months)

• Positive test documents persistent infection
• ELISA
  
  • Routine screening test
  • False positives (do Western blot to make sure)
• Western blot (confirms ELISA + cats)
  
  • Does not distinguish vaccine antibodies
• RT-PCR
  
  • Antigen
    
    • Vaccinated cats
    • Kittens with maternal antibodies
    • Up to 50% false neg. (low viremia)

Question 11

How do you treat a cat with FIV?

Answer 11

ALWAYS TREAT SECONDARY DISEASE (determine viral load by qPCR)

• Asymptomatic cats: no therapy
• Cats with signs: look for other causes for signs!
• Cats with acute infection: Zidovudine (AZT, antiviral)
  
  • Improves neuro signs and stomatitis
  • May cause anemia (stop if PCV <20%)
• Cats with stomatitis: AZT and ABC (avoid steroids)
  
  • If co-infection with calicivirus: Interferon-omega
• If no improvement: remove all teeth (standard of care)
• Cats with neurological signs: if no other causes, AZT

Question 12

How do you prevent a cat from getting FIV?

Answer 12

• Keep cats indoors
• Test new cats before introducing in cattery
• FIV vaccine (outdoor cats and cats living with FIV + cats)
  
  • Whole virus
  • Always test BEFORE vaccine
  • If FIV +: may increase viremia
  • If risk of exposure: inactivated FPV vaccine?
• If FIV +
  
  • Neuter
  • PE every 6 months (CBC)
  • Aggressive therapy
  • EPO in anemic cats