Benjamin Lamglait , Andreas Brieger, Marie Pierre Rainville, Edouard Maccolini, Noémie Summa, Isabelle Langlois, Jonathan Stockman and Claire Vergneau Grosset
Objective: To describe epidemiological and clinical features of cystine urolithiasis in pet ferrets. Methods: Retrospective case control study on medical records from four private clinics and one teaching hospital for pet ferrets diagnosed with cystine urolithiasis confirmed by spectrophotometry presented between July 2014 and July 2019 in Quebec, Canada; these cases were then compared to a reference population of 210 ferrets (controls) presented at the same facilities over the same timeframe. Results: Among the 36 identified cases, most affected ferrets were neutered males (32/36, 89%) and the mean age at presentation was 1.8 (± 1.0 standard deviation) year. Grain-free diets of six different brands were offered for at least three weeks prior to the presentation to 34/36 (94%) of the included cases. The ferrets that developed cystine urolithiasis were 57.9 times (Odds ratio [OR], 95% Confidence interval [95% CI]: 11.0, 304.8) more likely to receive a grain-free diet compared to the reference population. No significant difference in the values for the energy, protein, cysteine, and methionine contents were detected between the grainfree and the cereal-based diets offered to these pet ferrets. Among ferrets with uroliths, those with urethral calculi were 4.7 times (OR, 95% CI: 2.1, 10.4) more likely to develop an acute urinary tract obstruction. Conclusion: Although a definitive causation could not be drawn solely from these clinical cases, this case control study highlights a possible nutritional aetiology in the complex pathogenesis of cystine urolithiasis in ferrets