RESUMO
OBJECTIVE: To compare the effect of antivenom administration on mortality, hospitalization duration, and cost of hospitalization for dogs envenomated by Crotalus viridis. DESIGN: Retrospective study (January 2004-December 2012). SETTING: Private veterinary emergency and referral center. ANIMALS: One hundred thirteen dogs with confirmed C. viridis envenomation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Dogs were divided into groups treated with either supportive care only (group 1) or supportive care plus antivenin crotalidae polyvalent (group 2). A modified snakebite severity score was used to compare patients from group 1 and group 2. Patients in group 2 received one 10 mL vial of antivenin crotalidae polyvalent over 4-6 hours. The mortality rate was 1.8% (2/113). Group 1 had a median duration of hospitalization of 20 hours (range, 8-50 hours), while group 2 had a median duration of hospitalization of 24 hours (range, 1.5-74 hours). Group 1 had a median cost of hospitalization of 1050.00 USD (range, 423.52-2266.09 USD) while group 2 had a median cost of hospitalization of 2002.19 USD (range, 1139.91-6908.01 USD). Both the duration of hospitalization (P < 0.01) and the cost of hospitalization (P < 0.01) were significantly greater in the group of dogs receiving antivenom. CONCLUSIONS: Both the cost and the duration of hospitalization were significantly greater in the group of dogs that received antivenom. The difference in cost between the groups was approximately the cost of the antivenom vial and administration. Amongst the parameters evaluated, no significant benefit was associated with antivenom administered to dogs envenomated by C. viridis.