Surgical Site Infection and Antimicrobial Resistance After Mastectomy in Dogs and Cats: A 615‐Case Multicentre Cohort and Infection‐Control Audit
Mohammad Hedayatinia, Ferdos Gorjian, Mobina Pato, Mohammad Ali Maadi, Reza Ahmadi, Arman AbdousABSTRACT
Background
Surgical site infection (SSI) is an important complication after mastectomy and antimicrobial resistance may complicate treatment.
Objectives
To estimate 30‐day SSI incidence after mastectomy in dogs ( Canis lupus familiaris Linnaeus, 1758) and cats ( Felis catus Linnaeus, 1758), evaluate patient‐ and procedure‐related factors, describe perioperative antimicrobial use and microbiology and assess clinic infection‐control practices.
Methods
This multicentre retrospective cohort included 615 mastectomy procedures from 12 veterinary clinics in Tehran Province, Iran, between 2020 and 2025. SSI‐positive records were independently re‐reviewed by two investigators using contemporary veterinary SSI terminology. Clinic‐stratified conditional logistic regression evaluated seven clinically selected predictors.
Results
SSI occurred after 54/615 procedures (8.8%; 95% CI, 6.8%–11.3%); 50 infections were superficial and four deep. Surgical duration per 30 min (aOR, 2.37; 95% CI, 1.61–3.49), intraoperative hypothermia (aOR, 3.66; 95% CI, 1.39–9.62), body condition score per point (aOR, 1.60; 95% CI, 1.05–2.42) and previous major surgery (aOR, 3.57; 95% CI, 1.49–8.55) were associated with SSI. An MDR isolate was identified in 16/33 cultured SSI cases and antimicrobial–isolate discordance was present in 15/30 assessable comparisons. Mean clinic infection‐control audit score was 4.6 ± 1.7/10.
Conclusions
Longer surgery, intraoperative hypothermia, higher body condition score and previous major surgery were associated with SSI in this predominantly canine cohort of intact animals undergoing mastectomy without concurrent ovariohysterectomy. These associations were not independently demonstrated in cats. The findings support standardised surveillance, perioperative risk reduction, culture‐guided treatment and antimicrobial stewardship.
Clinical trial registration
Not applicable. This was a retrospective observational study and clinic‐level audit and was not a clinical trial.