Arginine requirement and ammonia toxicity in ferrets.

Hyperammonemia of varying magnitude was produced in young, male ferrets by either feeding them a purified diet containing low amounts of arginine or by intraperitoneal injections of jackbean urease. The responses were different depending on the method used to produce hyperammonemia. When hyperammonemia was produced by feeding a synthetic diet containing less than 0.2% arginine, ferrets developed encephalopathy soon after eating the diet and recovered after 4 hours. Although intraperitoneal injection of jackbean urease (100 IU/kg) caused severe hyperammonemia, ferrets did not become sick. Ferrets injected with 450 IU/kg of jackbean urease developed hyperammonemia but developed encephalopathy only after 15 hours. Ferrets showed remarkable capacity to tolerate elevated blood ammonia levels.