Brock A Paige, Grunkemeyer Vanessa L, Fry Michael M, Hall James S, Bartges Joseph W
J Avian Med Surg. 2013 Dec;27(4):264-8. doi: 10.1647/2012-049.
To evaluate the relationship between osmolality and specific gravity of urine samples from clinically normal adult parrots and to determine a formula to convert urine specific gravity (USG) measured on a reference scale to a more accurate USG value for an avian species, urine samples were collected opportunistically from a colony of Hispaniolan Amazon parrots (Amazona ventralis). Samples were analyzed by using a veterinary refractometer, and specific gravity was measured on both canine and feline scales. Osmolality was measured by vapor pressure osmometry. Specific gravity and osmolality measurements were highly correlated (r = 0.96). The linear relationship between refractivity measurements on a reference scale and osmolality was determined. An equation was calculated to allow specific gravity results from a medical refractometer to be converted to specific gravity values of Hispaniolan Amazon parrots: USGHAp = 0.201 +0.798(USGref). Use of the reference-canine scale to approximate the osmolality of parrot urine leads to an overestimation of the true osmolality of the sample. In addition, this error increases as the concentration of urine increases. Compared with the human-canine scale, the feline scale provides a closer approximation to urine osmolality of Hispaniolan Amazon parrots but still results in overestimation of osmolality.
为评估临床正常成年鹦鹉尿液样本的渗透压与比重之间的关系，并确定一个公式，将参考标准下测得的尿比重（USG）转换为更准确的鸟类尿比重值，我们从一群伊斯帕尼奥拉亚马逊鹦鹉（Amazona ventralis）中随机采集了尿液样本。使用兽医折射仪对样本进行分析，并在犬用和猫用两种标准下测量比重。通过蒸气压渗透压法测量渗透压。比重和渗透压测量结果高度相关（r = 0.96）。确定了参考标准下的折射率测量值与渗透压之间的线性关系。计算出一个方程，以便将医用折射仪测得的比重结果转换为伊斯帕尼奥拉亚马逊鹦鹉的比重值：USGHAp = 0.201 + 0.798(USGref)。使用参考犬用标准来估算鹦鹉尿液的渗透压会导致对样本真实渗透压的高估。此外，随着尿液浓度的增加，这种误差也会增大。与人类 - 犬用标准相比，猫用标准更接近伊斯帕尼奥拉亚马逊鹦鹉尿液的渗透压，但仍会导致渗透压的高估。
