Clinical and laboratory findings in chronic conjunctivitis in cats: 91 cases (1983-1991)

Clinical findings and laboratory test results from 91 cats with chronic conjunctivitis were studied to determine the causes of the disease and the sensitivity of diagnostic procedures used, and to identify correlations between results of various diagnostic procedures and clinical or signalment variations. Mean age of affected cats was 2.9 +/- 2.7 years (+/- SD), with a range from 1 month to 11 years. Conjunctivitis was more likely to be bilateral (56 cats) than unilateral (35 cats). In cats tested for FeLV or feline immunodeficiency virus infection, 15 and 8.5%, respectively, of the results were positive, compared with 4 and 2.6% for the general hospital population. Culturing or immunofluorescent assay (IFA) for feline herpesvirus 1 (FHV-1) and Chlamydia psittaci IFA resulted in identification of pathogens (positive test results) in 19% (FHV-1) and 18% (C psittaci) of tested cats. For FHV-1, culturing was more sensitive than was IFA, yielding positive results in 19 vs 8.8% of cases. In only 1 cat were FHV-1 and chlamydiae recovered. The probability of positive test results for FHV-1 or chlamydiae was unrelated to concurrent corneal disease, unilateral vs bilateral involvement, or age. Cause of conjunctivitis could not be definitively determined in the remaining 35 cases tested for both agents. Bacterial species considered to be potentially pathogenic were isolated from conjunctival sac specimens in only 1 of 38 attempts. Cytologic changes considered compatible with chlamydial or FHV-1 infection (intracytoplasmic inclusions or multinucleated epithelial cells, respectively) were found in 8 and 5 cases, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)