Refractometry is utilized routinely to evaluate canine urine specific gravity (USG) in veterinary clinical settings. We aimed to determine if the magnitude of interobserver reliability when assessing canine USG via refractometry could impact clinical judgment. USG was determined in 38 dogs by 3 registered veterinary technicians (RVTs) using both an optical analog refractometer and a digital refractometer. Summary statistics were reported, interobserver reliability was assessed via intraclass correlation coefficient (ICC) analysis through a 2-way mixed-effects model, and agreement between RVT pairs was compared through Bland–Altman plots. The median analog refractometer USG measurement was 1.018 (range: 1.004–1.040) and for the digital refractometer was 1.0176 (1.0035–1.0357). The analog refractometer average measure ICC was 0.995 (95% CI: 0.992, 0.997; p < 0.001). The digital refractometer average measure ICC was 0.999 (95% CI: 0.999, 1.000; p < 0.001). Strong agreement between all pairs of RVTs was seen via Bland–Altman plots for both analog and digital refractometers, with 95% CIs spanning no more than 0.002 in either the positive or negative direction for all pairings. The interobserver variability in canine USG measurements by RVTs was trivial and did not impact clinical judgment and decision-making.

在兽医临床环境中，屈光度法常规用于评估犬尿比重 (USG)。我们旨在确定通过屈光度法评估犬 USG 时观察者间可靠性的大小是否会影响临床判断。USG 由 3 名注册兽医技术人员 (RVT) 使用光学模拟折射仪和数字折射仪在 38 只狗中测定。报告了汇总统计数据，通过 2 路混合效应模型通过组内相关系数 (ICC) 分析评估了观察者间的可靠性，并通过 Bland-Altman 图比较了 RVT 对之间的一致性。模拟折光仪 USG 测量值的中位数为 1.018（范围：1.004-1.040），数字折光仪为 1.0176（1.0035-1.0357）。模拟折光仪平均测量值 ICC 为 0.995 (95% CI: 0.992, 0.p  < 0.001)。数字折光仪平均测量值 ICC 为 0.999（95% CI：0.999, 1.000；p  < 0.001）。通过模拟和数字折光仪的 Bland-Altman 图可以看到所有 RVT 对之间的高度一致性，所有配对的正向或负向的 95% CI 跨度不超过 0.002。RVT 对犬 USG 测量的观察者间差异很小，不会影响临床判断和决策。