Description
Feline herpesvirus 1 (FHV-1), feline calicivirus (FCV), feline influenza virus (rarely reported but emerging), Bordetella bronchiseptica, Chlamydia felis, and Mycoplasma felis contribute to feline upper respiratory infection (URI) complex, often co-infecting in shelters or multi-cat homes. FHV-1 causes acute sneezing, bilateral serous-to-mucopurulent nasal/ocular discharge, conjunctivitis, corneal ulcers (dendritic), blepharospasm, and fever; lifelong latency leads to recurrent herpetic keratitis with stress.
FCV presents with oral ulcers, hypersalivation, anorexia, nasal discharge, and occasional lameness (synovitis); virulent systemic strains add facial/footpad oedema, icterus, and high mortality. Feline influenza (H7N2 or novel strains) mimics flu with cough, nasal discharge, and fever but is uncommon. Bordetella bronchiseptica induces harsh cough, retching, and purulent nasal discharge; C. felis leads to chronic follicular conjunctivitis with chemosis; M. felis causes mild conjunctivitis and sneezing.?
Conjunctival/oropharyngeal swabs in viral transport medium, nasal swabs, or corneal cytology are primary samples; CBC shows neutrophilia, and imaging detects pneumonia. qPCR multiplex panels on swabs detect/quantify all agents simultaneously with high sensitivity, differentiating primary pathogens from carriers (e.g., high FHV-1/FCV loads in acute URI), identifying co-infections, strain-typing VS-FCV, and monitoring shedding or antiviral response, though positives require clinical correlation as asymptomatic carriage is prevalent.
