Adverse reactions to equine-derived F(ab')2 -antivenin in 54 dogs envenomated by Vipera berus berus

To describe the occurrence of acute and delayed adverse reactions following the administration of an equine-derived F(ab')2 -antivenin in dogs with Vipera berus berus envenomation.

Prospective study (2006-2009).

Private small animal clinics and university small animal teaching hospital in Norway.

Fifty-four dogs with Vipera berus berus envenomation treated with F(ab')2 -antivenin.

Administration of equine-derived antivenin for treatment of Vipera berus berus envenomation in dogs.

Acute adverse reactions to antivenin administration occurred in 4/54 dogs (7%), and facial swelling occurred in 2/54 dogs (4%), sudden respiratory distress in 1 dog, and vomiting occurred in 1 dog. The adverse reactions were self-limiting in 3 of the dogs, while 1 dog was treated with corticosteroids to reduce the facial swelling that occurred during administration of antivenin. No delayed adverse reactions believed to be associated with the antivenin administration were noted.

An occurrence of adverse effects comparable to the numbers reported in human medicine (10%) should be expected when administering F(ab')2 -antivenin to dogs with Vipera berus berus envenomation. The results are also comparable with rates of adverse effects reported with antivenin administration for crotalid-envenomated dogs. Further research is required to determine whether there is a relationship between adverse and the number of vials administered or repeated use in the same patient.