Retrospective description of the clinical use of chloramphenicol in client-owned cats: 12 cases (2015-2023).

Objectives: The study aimed to describe the clinical use of chloramphenicol in client-owned cats, examining the patient population, sites of infection, targeted pathogens, prescribed dosing regimen, outcomes and adverse effects.

Methods: Between 2015 and 2023, a retrospective medical record review was undertaken to identify a case series of cats treated with chloramphenicol.

Results: Twelve client-owned cats with complicated infections were treated with chloramphenicol at a median dose of 13.3 mg/kg (range 9.1-34.7) administered orally every 12 h for a median duration of 14.5 days. Within 30 days before starting chloramphenicol, 11/12 cats had received treatment with at least one antibiotic. The sites of infection included skin, urinary tract and multisystemic. Multidrug-resistant pathogens, for which no alternative oral antibiotic therapy was available, were commonly targeted. These included meticillin-resistant Staphylococcus species and multidrug-resistant Enterococcus faecium. Of the 12 cats treated with chloramphenicol, nine effectively achieved either bacteriologic or clinical cure. Chloramphenicol adverse effects were uncommon and limited to gastrointestinal upset, which was self-limiting or manageable with supportive treatment in two cats.

Conclusions and relevance: In these cats, the decision to treat with chloramphenicol was made because an alternative oral antibiotic was not available to target the multidrug-resistant pathogens. Infections of the skin or urinary tract were common. Overall, chloramphenicol was well tolerated, and treatment success was possible for most cats.