Blood chemical abnormalities in cattle with ruptured bladders and ruptured urethras

A study was undertaken to determine the blood chemical variables and compare changes that occurred with ruptured bladders and ruptured urethras in steers and yearling bulls. The fatality rates were 10.5% in steers with ruptured urethras and 50.8% in steers with ruptured bladders. Both groups had significantly decreased serum sodium and chloride values and significantly increased serum creatinine, blood urea nitrogen, and plasma protein concentrations compared to the normal group. Steers with ruptured bladders were more dehydrated, had significantly lower serum sodium and chloride values and had significantly higher blood urea nitrogen concentrations than steers with ruptured urethras. The combination of a decreased serum sodium, a decreased serum chloride, and a decreased ratio of serum phosphate to blood urea nitrogen occurred consistently within the ruptured bladder group. Of the variables examined, serum phosphate was the best prognostic indicator in the steers with ruptured bladders as all of the steers that died had a serum phosphate in excess of 2.9 mmol/L. The fluid and electrolyte changes are discussed.