A simple and intuitive formula for the estimation of urine osmolality (U_osm) using the measured concentrations of major active urine osmolytes over a wide range of urine dilutions was proposed in healthy cats. Sixty-three urine samples were retrieved using ultrasound-guided cystocentesis from sixteen healthy cats under 5 years of age receiving intravenous infusion over a period of 24 h. Samples were collected at baseline (T₀), T₂, T₆, T₁₂, and T₂₄. Urine osmolality was measured using a freezing-point osmometer, and the concentrations of osmolytes (urea, sodium, glucose, and potassium) were evaluated. A simple linear regression model for a clinical use was selected, and the agreement between the calculated and actual urine osmolalities was assessed. Urinary concentrations of urea, sodium and glucose were the three variables included in the model with the lowest AIC_C. Urine osmolality can be predicted accurately and precisely using urine urea, sodium and glucose with the following equation: U_osm = 1.25 × urea (mmol/l) or 20.87 × urea (g/l) + 1.1 × sodium (mmol/l) + 67 × glucose (mmol/l) or 3.72 × glucose (mg/dl). The concordance correlation coefficient for repeated measures between the actual and the calculated urine osmolality was extremely close to 1, which supported a high agreement: 0.996 (CI 95%: [0.993; 0.998]). In a population of healthy cats, urine osmolality can be predicted accurately and precisely using urinary urea, sodium and glucose concentrations. Similar formulae could potentially be established to help the clinician in pathological situations.

在健康猫中，提出了一种简单直观的公式，用于估计尿液渗透压（U _osm），该公式使用各种尿液稀释液中主要活性尿液渗透压的测量浓度进行估算。使用超声引导的膀胱穿刺术从24岁以下接受静脉输液的5岁以下的16只健康猫中检索了63个尿液样本。在基线（T ₀），T ₂，T ₆，T ₁₂和T ₂₄收集样品。使用冰点渗透压计测量尿渗透压，并评估渗透压浓度（尿素，钠，葡萄糖和钾）。选择用于临床的简单线性回归模型，并评估计算出的尿渗透压与实际尿渗透压之间的一致性。模型中包括的三个变量具有最低的AIC _C尿液中的尿素，钠和葡萄糖浓度。尿渗透压可以准确和精确地利用尿尿素，钠和葡萄糖下面的公式来预测：U _OSM = 1.25×尿素（mmol / l）或20.87×尿素（g / l）+ 1.1×钠（mmol / l）+ 67×葡萄糖（mmol / l）或3.72×葡萄糖（mg / dl）。实际和计算的尿渗透压之间的重复测量的一致性相关系数非常接近1，这表明较高的一致性：0.996（CI 95％：[0.993； 0.998]）。在一群健康的猫中，可以使用尿中的尿素，钠和葡萄糖浓度来准确，准确地预测尿渗透压。可能会建立类似的公式来帮助临床医生应对病理情况。