Copperhead (Agkistrodon contortrix) envenomation of dogs: 52 cases (2004-2011)

Copperhead envenomation is common within the US, and no studies exist describing the clinical course of copperhead envenomation in dogs. Almost all treatment decisions regarding those bites are extrapolated from retrospective studies evaluating the clinical course of rattlesnake bites. Because copperheads and rattlesnakes produce venom with different potency, assumptions that treatment of the different envenomations should be similar may be incorrect. The purpose of this retrospective study was to evaluate the clinical course of copperhead envenomation in dogs and administered treatments. Medical records of 52 dogs treated for copperhead envenomation were reviewed, and owners were contacted regarding outcome. The most common clinical signs associated with copperhead envenomation included swelling, pain, and ecchymosis. Clinicopathological abnormalities (e.g., thrombocytopenia, elevated clotting times, leukocytosis) were mild, and red blood cell morphology changes and coagulopathies were rare. Most dogs were treated with antimicrobials, analgesics, and fluid therapy. No dogs in this study required the use of antivenin and all survived to discharge. This study found that the clinical course after copperhead envenomation is generally limited to local rather than systemic illness. Copperhead envenomation in dogs is largely self-limiting and responsive to supportive care with hospitalization for monitoring.