Factors affecting the repeated surgery of urolithiasis in dogs after surgical removal at the lower urinary tract

Abstract

The objective of this case-control study was to identify the risk factors associated with the repeated surgery of canine urolithiasis at the lower urinary tract after surgical removal. There were 87 dogs included in this study between August 1st, 2014 and July 31st, 2016 at the Small Animal Teaching Hospital, Chiang Mai University, Thailand. Post-operative monitoring was performed until July 31st, 2017, the repeated surgical rate was 24.13% (21 of 87 dogs). The interval between the surgical episodes varied from 2 months to 36 months. Study variables included the type of primary diet, signalment, post-operative antibiotics, urinalysis, bacterial identification, uroliths analysis, post- operative diet, source of drinking water, and urination behavior. Missing variables and the information of repeated surgery from the medical record were obtained by a telephone interview of the owner. Dogs with struvite uroliths had a 16.54 times (95% CI =1.62 – 4.89 x 102 ; p-value = 0.040) greater risk of repeated surgery when compared with the non-struvite uroliths. This result strongly supports the idea that the surgical removal of struvite uroliths in the dog should not be considered as the final step of the treatment plan. Further analysis to identify the type of uroliths is warranted in order to identify dogs with a high risk of repeated surgery. Reducing the concentration of urolith precursors by using a specific diet or drinking more water, and changing the urination management, are recommend. Client education on how to reduce risk of uroliths reformation should be a high priority.