Suspected tolazoline toxicosis in a llama

Clinical signs of tolazoline toxicosis developed in a 4-year-old Hama that received 2 doses of tolazoline hydrochloride to reverse xylazine-induced se dation. The full first dose (4.3 mg/kg [2.0 mg/lb] of body weight) was erro neously injected IV, and the second dose was administered half IV, half IM 45 minutes later, because the Ilama became weak and recumbent. Signs of anx iety hyperesthesia, profuse salivation, and tachypnea were the first detect able clinical signs of tolazoline toxicosis. Convulsions, hypotension, gast rointestinal tract hypermotility, and diarrhea also developed. The Ilama wa s treated successfully with IV administration of diazepam, phenylephrine, a nd lactated Ringer's solution supplemented with potassium chloride and oxyg en administered via nasal insufflation. We suggest that the maximum dose of tolazoline administered at any one time to Ilamas not exceed 2 mg/kg (0.91 mg/lb). Furthermore, tolazoline should be administered slowly IV or IM to reduce the risk of adverse reactions.