Abstract
The urea clearance in the dog relative to the creatinine (glomerular) clearance is essentially the same in acidosis and alkalosis as in the normal. At low plasma urea values in acidosia the urea + ammonia clearance is considerably higher than the urea clearance and may exceed the creatinine (glomerular) clearance. The magnitude of this discrepancy between the urea and the urea + ammonia clearances depends on the degree of acidosis and the height of the plasma urea, being greater the more marked the acidosis and the lower the plasma urea.