Feline infectious Disease & Vaccines part 2

FIV & FELV overview

Caused by Retroviruses

• Slow to develop

• Clinical signs occur at varying times

• Found in cats that are seemingly healthy

retrovirus overview

Enveloped viruses

• Sensitive to heat & disinfectants

• Often create oncogenic infections

Feline Leukemia virus

More pathogenic

Major cause of death

Prevalence has decreased

FeLV transmission

Disease of social cats

shed in saliva

Grooming and licking

Transplacently

fomites

What cats are at a great er risk for FeLV

Those exposed via prolonged

close contact

Cats living with infected cats or

with cats of unknown status

Cats allowed outdoors

unsupervised

Kittens born to infected mothers

FELV pathogenesis

Oronasal exposure

Replication in regional lymphoid

tissue

Spread to lymphoid tissues &

bone marrow*

Latent bone marrow infection

established

Further spread & shedding

FeLV possible outcomes for regressor cats

Regressor cats

Viral replication stopped by CMI response then

Virus eliminated from body

Cats have high levels of FeLV neutralizing

antibody

Never have (+) antigen test

Possible outcomes for transient viremia cats (virus in blood)

Transient viremia (3-6 weeks)

• Virus spreads within lymph tissue

• Cats are infectious to others

• Have (+) antigen test

• Many will clear viremia/terminate the virus

& develop antibodies

• Those that don’t —>persistently infected

Possible outcomes for persistent viremia FeLV

Persistent viremia

• Bone marrow infected

• Precursor cells produce infected

granulocytes and platelets

• High level viremia

• Have (+) antigen test

Possible outcomes for latent (dormant) bone marrow infection FeLV

Those that don’t eliminate the virus

• Have (-) antigen test

• Can be re-activated (+) test

• Latent cats don’t shed virus until re-

activated

FeLV clinical signs

The incubation period is months to years

Most persistently infected cats die

Related to non-neoplastic disease

FeLV early signs

Lethargy, fever, lymphadenopathy

or no signs at all

Later stages of chronic infection

FeLV diagnosis

ELISA test (IDEXX Snap Test) detects FeLV antigen

Positive cats should be retested in 4-6 months

IFA test used to confirm ELISA

FeLV vaccines do not interfere with results on

ELISA, IFA, or any other available FeLV tests!

FeLV treatment

symptomatic and supportive care

FeLV prevention

Decrease exposure

Keep infected and infection

free separated

Don’t allow sharing of

house items

Test all new cats prior to

entering the home

Vaccination

FeLV vaccination

Start at 8 weeks booster once in 3-4 weeks then 1 year booster

Not a core vaccine

Recommended that all kittens be vaccinated

FeLV immunodeficiency Virus

An acquired immunodeficiency syndrome

Comparable to HIV in humans

Increased risk for opportunistic infections, neurologic diseases, and tumors

Does not cause a severe clinical syndrome

With proper care, infected cats can live many years and die from unrelated causes

FIV transmission

shed through saliva

Saliva and blood most make contact

disease of fighting cats

Bite wounds necessary

Infection rates highest in free-roaming adult male cats