Feline infectious diseases Flashcards
Cat flu pathogenesis
Multiple aetiological agents
Highly transmissible
Infected cats become carriers and can spread the disease even if no clinical signs
Major aetiological agents in cat flu
Feline calicivirus (FCV) - 80%
Feline herpes virus (FHV-1) - 20%
Incubation period ~ 2-6 days
Shedding period ~2 weeks
Minor aetiological agents involved in cat flu
Bordatella bronchiseptica
Chlamydophila felis
Feline herpes virus
AKA feline rhinotracheitis
Large enveloped DNA virus - readily inactivated by household disinfectants
Pathogenesis of feline herpes virus
Acute infection:
- Chronic damage
- Clinical recovery
Clinical recovery:
- Carrier status
- True recovery
Carrier status -> latent virus -> reactivation -> virus shedding +/- clinical signs
Transmission of feline herpes virus
Direct contact via oro-nasal route
Indirect via fomites
Incubation and disease course of feline herpes virus
Incubation period: 2-17d
Disease course: typically 2-4 weeks
What percent of cats exposed to FHV become lifelong carriesr?
80-90%
Where does FHV lie latent?
Within the trigeminal ganglia
Clinical signs of FHV
Younger cats more likely to be affected, with more severe clinical signs
Anorexia, pyrexia, depression, sneezing, marked nasal and ocular discharges
Ocular signs common: acute and chronic conjunctivitis and ulcerative keratitis
High morbidity but usually low mortality
Clinical signs of FHV in pregnant queens
May see abortion or foetal reabsorption
Clinical signs of FHV in neonates
Osteolysis of turbinates
Persitent rhinitis/sinusitis
Clinical signs of FHV in kittens
Similar to adults but can also get symblepharon (adherence of conjunctiva to cornea)
What are branching dendritic ulcers pathognomic for?
Feline herpes virus 1 (FHV-1)
Diagnosis of feline herpes virus
Acute stage: oropharyngeal swab in viral transport medium for virus isolation. PCR also available. Not definitive on clinical signs.
Chronic stage: cannot be reliably detected due to latency
Treatment of feline herpes virus
Famciclovir
(coverted in vivo to penciclovir (PCV))
Inhibits viral DNA polymerase
Feline calicivirus (FCV)
More common than FHV but milder signs
RNA non-enveloped virus
Antigenically diverse
Transmission of feline calicivirus
Oro-nasal or fomite (most important) spread
Most cats become temporary carriers ubt eventually clear the infection
What percentage of cats remain carriers of feline calicivirus and persistenly shed?
<10%
