Radiographic distribution of ureteral stones in 78 cats

Objective To document the distribution of ureteral stones in cats. Study design Retrospective case series. Animals Seventy‐eight cats. Methods Abdominal radiographs with ureteral stones were reviewed. The location of stones was categorized as proximal ureter (PU), midureter (MU), or ureterovesicular junction (UVJ). The number, size, and location of stones were recorded by using the kidneys and vertebral bodies as landmarks. Stone location in cats with 1 versus multiple stones was assessed. Descriptive statistics were used to describe the incidence of ureteral stone location. Results Among cats with a single stone (44%, 34/78), 44% (15/34) had a stone in the PU, 41% (14/34) had a stone in the MU, and 15% (5/34) had a stone at the UVJ. When multiple stones were present, 61% (27/44) of cats had at least 1 stone located in the PU, 70% (31/44) had at least 1 stone located in the MU, and 34% (15/44) had at least 1 stone located at the UVJ. The L4 vertebral body most commonly marked stone location in cats with 1 stone and the most distal stone in cats with multiple stones. Stones located at the UVJ site were more common in male (37%) than in female (12%) cats (P = 0.004). Larger stone size was associated with a more proximal location (P = 0.04). Conclusion Ureteral stones were more commonly located in the PU and the MU than in the UVJ. UVJ stones were more common in male than in female cats, and larger stones had a more proximal location. Clinical significance This study enhances our understanding of feline ureteral stone location and identifies a correlation between stone location and stone size.