Antimicrobial Resistance Patterns of Cutaneous Samples in Companion Animals in North-Western Italy from 2013 to 2024

Skin diseases are among the most frequently diagnosed conditions in companion animals and have historically been treated empirically with antibiotics, contributing to the emergence and persistence of antimicrobial resistance (AMR). In recent years, greater awareness of AMR has led to a reduction in antibiotic use in veterinary medicine, particularly in dermatology. To assess AMR trends in skin infections and evaluate the use of diagnostic tools to guide antimicrobial prescriptions, we conducted a retrospective study of medical records from a veterinary hospital in northwestern Italy between 2013 and 2024. A total of 447 antimicrobial susceptibility tests from dogs and cats with clinical signs of skin disease were analyzed. Of these, 391 yielded positive bacterial cultures, and 56 were negative. Most positive samples came from dogs (83.4%), with cats accounting for 16.6%. The most frequently isolated bacterial families were Staphylococcaceae, Enterobacteriaceae, and Pseudomonadaceae. Amoxicillin-clavulanic acid was prescribed in 36.6% of patients, fluoroquinolones in 25.9%, while 17% received only detergent–disinfectant products. Among first-line drugs, ampicillin showed the lowest susceptibility, with resistance exceeding 60%, whereas imipenem (used as an indicator of carbapenemase production but avoided in veterinary medicine) retained high activity, with susceptibility rates of 77.2% in dogs and 90.3% in cats. These findings are clinically relevant, but continuous AMR surveillance remains essential within a One Health framework to limit the spread of resistant bacteria and resistance genes to cohabiting humans.