Incidence and characteristics of acute-onset postoperative bacterial and sterile endophthalmitis in dogs following elective phacoemulsification: 1,447 cases (1995-2015).

OBJECTIVE To characterize and determine the incidence of acute-onset (ie, developing ≤ 6 weeks after surgery) postoperative infectious and sterile endophthalmitis in dogs following elective cataract surgery. DESIGN Retrospective case series. ANIMALS 2,630 eyes of 1,447 dogs that underwent elective unilateral or bilateral cataract surgery by phacoemulsification at Cornell University from 1995 through 2015. PROCEDURES Medical records were reviewed to collect and summarize data regarding dog signalment, clinical findings, diagnostic test results, surgery characteristics, eye or eyes affected, concurrent major systemic diseases, treatments, and clinical outcome. RESULTS Infectious endophthalmitis developed in 4 eyes of 4 dogs during the follow-up period, representing 0.15% of eyes and 0.28% of dogs that underwent surgery. Unilateral sterile endophthalmitis developed in 3 (0.11%) eyes of 3 (0.21%) dogs. All cases of infectious endophthalmitis were unilateral and in pseudophakic eyes and followed bilateral cataract surgeries. Clinical signs consistent with infectious endophthalmitis developed a median of 18 days after surgery and included marked and progressive hypopyon; Staphylococcus or Streptococcus spp were recovered from aqueous and vitreous humor samples. All eyes with infectious endophthalmitis responded poorly to medical treatment and were enucleated. In 2 eyes with infectious endophthalmitis, corneal incision nonunion with epithelial downgrowth was identified histologically and postulated as the route of bacterial entry into the globe. CONCLUSIONS AND CLINICAL RELEVANCE Bacterial endophthalmitis following elective phacoemulsification was uncommon in the dogs of this study. Introduction of bacteria into the eye may occur during surgery or in the postoperative period from corneal incisions that fail to heal normally.