Ovine blood chemistry values measured during ammonia toxicosis

Venous blood values were determined on 19 Southdown sheep (9 adult ewes and 10 wether lambs). Principal sheep were given 12.5 ml of 3.3M urea solution/kg of body weight, which produced acute ammonia toxicosis. Whole blood ammonium-nitrogen was determined by ion exchange; venous blood gases and pH were measured with a pH blood gas analyzer; and 23 serum chemical analyses were obtained with a sequential multiple autoanalyzer computer. Analysis of variance for the data revealed significant changes for 20 values. The values are presented and discussed with regard to those that changed beyond acceptable limits (whole blood ammonium-nitrogen, venous blood pH, serum glucose, serum lactate dehydrogenase, serum alkaline phosphatase, serum creatine kinase, serum urea nitrogen, serum inorganic phosphorus, serum sodium, and serum potassium), those that changed within acceptable limits (PVo2, PVco2, serum triglycerides, serum free fatty acids, plasma volatile fatty acids, serum aspartate aminotransferase, serum total protein, serum albumin, serum creatinine, urea nitrogen-creatinine ratio, serum uric acid, serum cholesterol, serum low-density lipoproteins, serum calcium, serum iron and serum chloride), and those with no change (total and direct serum bilirubin and albumin-globulin ratio). Metabolic consequences of ammonia toxicosis are considered with regard to energy, lipid , protein, and acid-base and electrolyte balances. Blood values having possible laboratory diagnosis value and considerations for therapeutic adjustment are discussed.