Risk factors, complications, and outcomes of cystotomy in guinea pigs: 25 cases (2010-2023).

Objective: To describe the complications, surgical outcome, and prognosis associated with cystotomies in guinea pigs.

Methods: A retrospective review of medical records of guinea pigs undergoing cystotomy for uroliths or urethroliths between 2010 and 2023.

Results: 25 guinea pigs were included in the study. Uroliths were confirmed on radiographs in all 25 cases, with 9 patients (36%) having at least 1 stone within the urethra. The cystotomy procedure was associated with an intraoperative complication rate of 24% and a short-term complication rate of 76%. Discomfort was the only presenting clinical sign significantly associated with survival, with a risk of dying prior to discharge that was a sixth of the risk of dying if a patient presented without signs of discomfort (risk ratio = 0.177). For patients with a stone within the urethra, the probability of death prior to discharge was 6 times that of patients with a stone within the bladder (P = .010; risk ratio = 5.966).

Conclusions: Cystotomies were associated with a mortality rate of 40% prior to discharge and 56% within the first month postoperatively. Further studies are needed to determine what specifically may lead to the high mortality rate as well as whether alternative minimally invasive procedures may be helpful in improving outcomes.

Clinical Relevance: This study is the first to document risk factors, complications, and outcomes of a cohort of guinea pigs specifically undergoing cystotomy for urolithiasis. Given the high risk for complications and mortality, caution and owner preparation must be considered when a cystotomy is recommended for guinea pig patients.