As a Cause of Acute-onset Febrile Illness in Cats

Case Series Summary: At different time points spanning 6 months, three adopted feral flea-infested cats, residing in the household of a veterinary technician, became acutely anorexic, lethargic and febrile. Enrichment blood culture/PCR using alpha Proteobacteria growth medium (BAPGM) confirmed initial infection with the same genotype in all three cases. With the exception of anemia and neutropenia, complete blood counts, serum biochemical profiles and urinalysis results were within reference intervals. Also, tests for feline leukemia virus, feline immunodeficiency virus, and feline coronavirus antibodies were negative. Serial daily temperature monitoring in one case confirmed a cyclic, relapsing febrile temperature pattern during 1 month, with resolution during and after treatment with azithromycin. Western immunoblot (WB) results did not consistently correlate with BAPGM enrichment blood culture/PCR results or indirect fluorescent antibody (IFA) titers, and WB titration results were not informative for establishing antibiotic treatment failure. During the respective follow-up periods, no illnesses or additional febrile episodes were reported, despite repeat documentation of bacteremia in two cats available for follow-up (one with the same genotype and the other with a different genotype); one cat was, unfortunately, killed by dogs before follow-up testing.

Relevance And Novel Information: We conclude that microbiological diagnosis and treatment of infection in cats can be challenging, that antibody titration results and resolution of clinical abnormalities may not correlate with a therapeutic cure, and that fever and potentially neutropenia should be differential diagnostic considerations for young cats with suspected bartonellosis.