Characterization and treatment of water, electrolyte, and acid-base imbalances of induced urethral obstruction in the cat.

Urethral obstruction induced in adult male cats caused clinical signs identical with those observed in naturally occurring disease. Central nervous system depression, anorexia, dehydration, vomiting, muscle weakness, and hypothermia occurred. Weight loss (due to water loss and catabolism), metabolic acidosis, mild hyponatremia, hyperkalemia, hypermagnesemia, hypocalcemia, hyperphosphatemia, hyperglycemia, azotemia, and hyperproteinemia were also observed. Serum amylase, alkaline phosphatase, and alanine aminotransferase activities were normal. Ten of 13 cats (group 1), with 72 hours' induced obstruction but not treated with parenteral fluids, died either before the obstruction was relieved or within 8 days afterward. Eight cats (group 2) with induced obstruction for 49 to 98 hours developed severe clinical and biochemical alterations. Treatment with a multiple-electrolyte solution, in addition to relief of urethral obstruction, resulted in favorable clinical and biochemical responses. These cats survived and were clinically healthy at 9 to 10 days after relief of obstruction. It was concluded that use of a multiple-electrolyte solution to correct acidosis, restore circulatory volume, and enhance renal excretion of potassium was effective supportive therapy after urethral obstruction was removed.