Usage patterns of carbapenem antimicrobials in dogs and cats at a veterinary tertiary care hospital

Abstract Background Carbapenems are a class of antimicrobials reserved for resistant infections or systemically ill people, yet the extent and context in which they are prescribed in the small animals is understudied. Hypothesis/Objective To describe cases in dogs and cats treated with carbapenems to establish baseline data regarding the types of infections, outcomes, and resistance profiles of target infections. We hypothesize that prescribing practices for carbapenems at a veterinary tertiary care hospital would not comply with the recommended use guidelines in human medicine. Methods Retrospective study of veterinary medical records from all dogs and cats prescribed carbapenems between May 1, 2016, and April 30, 2017. Results A total of 81 infections (71 in dogs and 10 in cats) representing 68 animals (58 dogs and 10 cats) involving carbapenem use were identified. Cultures were performed in 65/81 (80%) infections, and antimicrobial use was de‐escalated or discontinued in 10/81 (12%) infections. The average duration of treatment was 27.5 days and ranged from 1 to 196 days. Resistance to more than 3 antimicrobial classes was present in 57/115 (50%) isolates. Resistance to carbapenems was found in 2/64 (3%) of the bacterial isolates with reported carbapenem susceptibility. Conclusions and Clinical Importance The majority of carbapenem use at a veterinary tertiary care hospital was prescribed in conjunction with culture and sensitivity determination, with de‐escalation performed in a minority of cases, and treatment durations longer than typically recommended in human medicine.