Consequences of intratumoral injection of a herbal preparation containing blood root (Sanguinaria canadensis) extract in two dogs.

Case Description: 2 dogs were referred for surgical removal of cutaneous tumors that had previously been treated by intratumoral injection of a herbal preparation containing blood-root (Sanguinaria canadensis) extract.
Clinical Findings: 11 days following injection of bloodroot extract into a small dermal tumor, dog 1 developed a large, soft, fluctuant cutaneous mass at the site of injection. Ultrasonographic evaluation of the mass revealed a fluid-filled central cavity with increased echogenicity of the surrounding subcutaneous tissues. Dog 2 had a small dermal tumor under the left mandible that had been treated in similar fashion. However, an exuberant reaction was not observed following injection of bloodroot extract in this dog.
Treatment and Outcome: Both dogs underwent surgical excision of the cutaneous tumors. Histologic evaluation revealed severe necrosis and inflammation in the excised tissues from dog 1. This dog experienced postsurgical wound complications and had a prolonged postsurgical recovery. Similar, although less severe, histopathologic findings were apparent in the excised tissues from dog 2; this dog recovered without complications.
Clinical Relevance: Various products containing bloodroot are marketed on the Internet for topical and parenteral treatment of cutaneous neoplasms in domestic animals. However, the antineoplastic properties, therapeutic efficacy, and adverse effects of these products are poorly described in the veterinary literature. Clinicians should be aware of the potential for harm caused by the use of these products.