Small animal Review

While uroliths are a less common cause of urinary tract signs in cats in the UK compared to the USA, studies have suggested that 10–15% of urinary tract infection (UTI) cases in the UK are due to urolithiasis. This recent paper by Tefft et al (2021), published in the Journal of Feline Medicine and Surgery, looked at the efficacy of a new diet with low struvite relative supersaturation for dissolution of feline struvite uroliths.

Of itself this is not a new approach, with diets designed to dissolve struvite uroliths first being used in 1983, but this paper has value in terms of using simple diagnostic criteria (radiographic moderately opaque, round to discoid uroliths in urine with a pH ≥6.5) to justify starting a struvite dissolution diet, when faced with at least 50% of uroliths being calcium oxalate in cats. Based on these criteria, 12/19 cats screened were enrolled and owners were supplied with the test dry diet to feed their cats exclusively.