Page 350 - Problem-Based Feline Medicine

342 PART 6 CAT WITH WEIGHT LOSS OR CHRONIC ILLNESS

Prognosis
No specific therapy has proven effective against the
virus in the long term, but reverse transcriptase In the acute or asymptomatic phases of the disease, it is
inhibitors and immunomodulating drugs may provide not possible to predict the short- or long-term prognosis.
some benefit in rescuing severely ill cats in the short-
Many cats appear to live for years with no or minimal
term. Although some drugs can reduce viral load
problems.
(AZT and PMEA), there are no studies showing a
proven clinical benefit long term, or resolution of In the terminal clinical phase, the prognosis is poor
infection, and long-term use is hindered by side to grave with average life expectancy of less than
effects. 1year.
Reverse transcriptase inhibitors may suppress viral
replication. Prevention
● Zidovudine (3′-azido-3′-deoxythymidine, AZT)
One vaccine has been approved for the prevention of
(5–15 mg/kg PO or 5 mg/kg subcutaneously q 12
FIV. There are still questions on its efficacy and the
hours) has been shown to improve clinical signs,
American Association of Feline Practitioners (AAFP)
but does not eliminate the virus.
has yet to recommend its use.
– Increased numbers of CD4+ cells and improve-
ment in CD4+:CD8+ ratios have occurred in nat- Until a proven effective vaccine is developed and the
urally infected FIV cats. ability to differentiate a false positive vaccine titer
– Remission in stomatitis has been reported. from infection, prevention is achieved by avoiding
– The virus may become resistant to AZT exposure to infected cats.
– Anemia and hepatotoxicity are potential side ● FIV-positive cats should be neutered to reduce the
effects. tendency to fight.
● Confinement of FIV-positive cats to indoors will
Immunomodulating drugs to potentiate the immune
reduce the spread of the virus, and will also reduce
response against the virus include:
the exposure of the affected cat to secondary infec-
● Evening primrose oil (550 mg PO q 24 hours).
tious diseases.
● Low-dose oral human recombinant alpha inter-
● In single-cat households or multiple-cat households
feron (30 IU/cat PO q 24 hours, 7 days on, 7 days
where all cats are seronegative for the virus, the ani-
off).
mals are at negligible risk if they are kept as indoor
● Acemannan, Propionibacterium acnes and
cats.
staphylococcal protein A have been suggested as
● FIV is readily killed by disinfectants and survives
immunomodulating agents in FIV infection.
only a few hours in the environment, so risk of
Aggressive supportive care and management of fomite transmission is low.
secondary infections are essential in FIV-positive
The FIV status of new cats should be determined prior
cats. All infections should be fully assessed in terms
to introduction to a group. Ideally these cats should be
of extent and appropriate treatment administered, ide-
rechecked in 4–6 weeks because of the latency period
ally based on culture and sensitivity results. Response
between exposure and production of antibody.
to treatment may be slower in FIV-infected cats, and
so sufficient duration of antibiotic must be adminis-
tered. CANCER CACHEXIA**
Appropriate preventative medicine is important in
Classical signs
immunosuppressed cats.
● Inactivated vaccines should be used against respira- ● Anorexia, muscle wasting and weight loss.
tory or enteric pathogens. ● Weakness, lethargy.
● However the ability of an FIV-infected cat to pro- ● Clinical signs associated with the
duce an adequate immune response to a vaccine is neoplastic lesion.
unknown.