DETECTION OF FELINE HERPESVIRUS-1 DNA IN CORNEAS OF CATS WITH EOSINOPHILIC KERATITIS OR CORNEAL SEQUESTRATION

Objective-To determine whether feline herpesvirus 1 (FHV-1) DNA is in the corneas of clinically normal cats and cats with eosinophilic kerat itis or corneal sequestration. Sample Population-Corneal biopsy specim ens obtained from cats referred for treatment of corneal sequestration or eosinophilic keratitis. Procedure-Corneal scraping or keratectomy specimens collected from clinically normal cats, cats with eosinophili c keratitis, and cats with corneal sequestration were evaluated for FH V-1 DNA by use of polymerase chain reaction (PCR). DNA was extracted f rom the tissue, and 1 mu g was assayed for FHV-1 by use of a single-ro und (40 cycles) PCR assay with primers directed at a 322-bp region of the thymidine kinase gene. Polymerase chain reaction positivity for cl inically normal and affected cats of various breeds was compared by ch i(2) analysis at alpha = 0.05. Results-The FHV-1 DNA was detected in 5 .9% (1/ 17) of corneas from clinically normal cats, in 55.1% (86/156) of corneal sequestra, and in 76.3% (45/59) of scraping specimens from cats with eosinophilic keratitis. Prevalence was significantly (P < 0. 001) greater for cats with corneal sequestration or eosinophilic kerat itis than for clinically normal cats. For cats with corneal sequestrat ion, prevalence of FHV-1 DNA was significantly lower in Persian and Hi malayan, compared with domestic shorthair and longhair breeds. Conclus ion-Data strongly imply involvement of FHV-1 in the pathogenesis of eo sinophilic keratitis and corneal sequestration. In Persian and Himalay an breeds, however, other nonviral factors also appear to be involved. Clinical Relevance-Feline herpesvirus 1 must be considered when treat ing cats with corneal sequestration or eosinophilic keratitis.