Feline upper respiratory tract syndrome Flashcards
predisposing environmental factors
- poor hygiene practices
- suboptimal temperatures
- poor ventilation
- poor quarantine policies
etiological agents?
Feline Calicivirus
Feline herpesvirus
Chlamydophilia felis
synergistic or opportunistic infections
- Mycoplasma felis*
- Bordetella bronchiseptica*
- Pasteurella, Pseudomonas, Staph, Strep, E. coli, Klebsiella*
Feline Calicivirus Characteristics
survives in environment up to 10 days at RT
Mode of transmission: direct, close contat, aerosols, fomites, feces, urine, carrier cats
Felfine Herpesvirus characteristics
24 hours at RT-fragile outer lipid envelope
mode of transmission: direct close contact, aerosols, fomites, vertical transmission, carrier cats
Chlamydophilia
survives a short period at RT
mode of transmission: direct, close contact, aerosol, fomites, feces & urine, carrier cats
Pathogenesis of Feline Calicivirus
incubation 2-6 days
infects oropharyngeal and URT epithelia and conjunctiva
Clinical signs for Felie Calicivirus
conjunctivitis
sneezing and nasal d/c
oral ulceration
lethargy, fever, pneumonia
limping kitten syndrome
last 1-3 weeks
Carriers of Feline Calicivirus
~50% become chronic carriers
tonsils and nasopharyngeal tissue
chronic continuous shedding
gingival redness or lymphoproliferative lesions
concurrent FIV shedding
Feline Calicivirus associated virulent systemic disease
highly contagious, spread through fomites
novel, genetically distinct strains of FCV isolated from infected cats
affects healthy, adult vaccinated cats
outbreaks
50% mortality
rapid disease spread
signs: fever, edema (limb & face), skin lesions (sores, crusts, alopecia)
pathogenesis of feline herpesvirus1
incubation period is 2-6 days
replicates in tonsil and respiratory tissue
local superficial necrosis of oral mucosa
secondary bacterial infection
Clinical signs of feline herpesvirus1
serous nasal/ocular d/c initially which progresses to mucopurulent and sneezing
poss sev conjunctivitis
resolves within 2-3 weeks
fever, anorexia, hypersalivation
pharyngitis, oral ulceration (uncommon)
complications of feline herpesvirus1
persistent and/or recurrent rhinitis (osteolysis and atrophy of nasal turbinates, predispose to bacterial inf)
repro tract (abort, fetal resorption)
CNS signs
ulcerative facial & nasal dermatitis
mortality (70% in kittens)
ocular complications
ocular com,plications of feline herpesvirus1
corneal ulceration (Dendritic ulcers)
conjunctivitis neonatorum
recurrent, refractory keratitis
corneal sequestration
Carrier cats of feline herpesvirus1
80-100% of infected ats
latency in trigeminal ganglia, optic nerves, olfactory bulbs, cornea
shed only intermittently for short perios
stress!
spontaneous shedding without clin sxs
Clinical signs of Chlamydophilia felis
incubation 3-5 days
ocular pathogen
sev persistent conjunctivitis
blepharospasm, chemosis
serous to mucopurulent ocular d/c
+/- sneezing, nasal d/c
improve with 1-3 weeks
Carrier cat of Chlamydophilia felis
unclear status
conjunctiva, feces, urine
most stop after 60 days
DDx for nasal d/c
- FHV
- FCV
- Chlamydophilia felis
- Bordetella
- Mycoplasma
- Secondary bacterial inf
- Cryptococcus
- Choanae atresia
- nasopharyngeal polyp
- larval migration
- allergic dz
- neoplasia (older cats)
- severe dental dz
Dx of URI
imaging: Nasal rads, Rhinoscopy, CT, MRI scans
Viral: virus isolation, serology, PCR assays
bacterial: cytology, PCR, cultures
Nasal rads
osteolysis, turbinate loss possible
fluid density common
bilateral
rhinoscopy
often not helpful
expensive, size limitations
virus isolation
low sensitivity
nasal, conjunctival, oropharyngeal swabs
Serology
acute and convalescent titers
often not practical
results difficult to interpret
PCR assays
rapid inexpensive, sensitive
deep nasal swabs, nasal bx, conjunctival swabs
feline upper respiratory disease panel
ID of nucleic acid sequence does not equal dz causation
can’t differentiate between pathogen and vaccine strain
intermittent shedding of virus
Cytology
cytoplasmic inclusion bodies from conjunctival smears (Giemsa stain)
present early in inf
poor sens and spec
PCR for Chlamydophilia felis
best sens and spec
tx for viral URI
symptomatic: fluid therapy, clean nostrils and eyes, nutritional support, +/- hospitalization
antiviral meds: topical idoxuridine and trifluridine, oral famciclovir)
abx for secondary inf
Chronic cases: L-lysine, aerosolization, 0.25% phenylephrine IN, nasal flushing, Zithromax, intermittent abx
Tx for bacterial infections
symptomatic care
tetracycline
all household cats should be treated
prognosis
2-3 weeks
+/- intermittent rhinitis
chronic snufflers
disease control
proper hygiene and animal handling
1:32 bleach:detergent solution
improve ventilation and temp
proper quarantine procedures
Vaccination
Feline Cryptococcus neoformans
most common systemic fungal disease
saphrophytic, budding yeast
growth enhanced in pigeon droppings
Pathogenesis of Cyrptococcus
entry via respiratory tract
localization in nasal cavity & sinsuses
smaller organisms reach alveoli
Clinical signs of Cryptococcus
sneezing
stertorous breathing
chronic nasal d/c (uni or bilateral, mucopurulent, blood tinged)
swelling, facial deformity
protrusion of granulomas from nares
Physical exam findings for Cryptococcus
regional lymphadenopathy
skin lesions (nodules, ulcerative, exudativee)
neurologic sxs (lethargy, blindness, ataxia, paresis, paralysis, seizures)
ocular lesions
Dx for cryptococcus
Rad findings: increased soft tissue density, +/- bone destruction
cytology: organisms on smear
biopsy
fungal cultures
antigen titers
tx for cryptococcus
antifungal therapy: itraconazole, amphotericin B, 5-flucytosine, fluconzale, ketoconazole
treat for 2 months past resolution of clinican signs
