Successful Treatment of a Southern Pacific Rattlesnake (Crotalus viridis helleri) Bite in a Caracal (Caracal caracal)

Abstract A caracal (Caracal caracal) was bitten on the lower lip by a southern Pacific rattlesnake (Crotalus viridis helleri) and quickly developed progressive, severe soft tissue swelling and bruising of this site. Initial laboratory results revealed prolonged clotting times within the first hour of envenomation, followed by signs of vasculitis and anemia. The caracal was successfully treated with intravenous crystalloids, four vials of polyvalent crotalidae antivenom, and transfusions of bovine hemoglobin glutamer-200 (Oxyglobin®) and fresh whole blood. The progressive soft tissue swelling and bruising halted and the coagulation parameters improved after administration of antivenom; however, the caracal continued to show neurologic dysfunction, including depression, weakness, muscle fasciculations, anisocoria, and ataxia. Administration of an additional vial of antivenom 72 hr after envenomation quickly corrected the weakness and muscle fasciculations, whereas the anisocoria and mild ataxia persisted fo...