Perioperative acute kidney injury in dogs undergoing elective desexing surgery

To report the incidence of acute kidney injury (AKI) in dogs after elective desexing surgery.

Prospective observational clinical study.

A group of 165 (71 male and 94 female) dogs admitted for castration or ovariohysterectomy.

Inclusion criteria were normal physical examination findings and no history of cardiovascular or renal disease. Serum creatinine (sCr) was measured before anaesthesia, and 24 and 48 hours postoperatively. AKI was defined by an increase (> 26 μmol L^-1) in sCr from preoperative to 24 or 48 hours postoperatively. Changes in mean sCr pre-to post-anaesthesia were compared using paired t-tests. Differences in variables were compared between dogs with and without AKI with Fisher's exact test for categorical data and continuous data using t-test or Mann-Whitney U test. Multivariable logistic regression was used to assess the significance of potential risk factors identified by univariable comparisons between AKI and non-AKI cases.

Mean ± standard deviation age and body weight were 2.1 ± 1.7 years and 20.3 ± 10 kg, respectively. Mean change in pre-sCr to 24 and 48 hours was -6.9 ± 32.8 and -0.2 ± 22.8 μmol L^-1, respectively (p > 0.05). sCr increased > 26 μmol L^-1 in eight dogs at 24 hours and in an additional four dogs at 48 hours. Twelve dogs (7.3%) were classified with AKI: one grade 2 AKI (sCr 175 μmol L^-1) and 11 as grade 1 (sCr increase > 26 μmol L^-1 but within reference range). In addition, four of these dogs had oliguria in the first 24 hours postoperatively. Hypotension occurred frequently (67.9%) and along with female sex was significantly associated with AKI.

Perioperative AKI may be a common complication of elective desexing surgery in dogs. Potential risk factors include hypotension and female sex.