Anthelmintic activity of paraherquamide in dogs.

Paraherquamide, an oxindole alkaloid metabolite of Penicillium paraherquei and Penicillium charlesii, was tested against the common gastrointestinal nematodes of dogs at a single oral dosage of 0.5, 1.0, or 2.0 mg kg-1. Efficacy was poor (less than 85%) against Ancylostoma caninum, Uncinaria stenocephala, Toxascaris leonina, Trichuris vulpis, and Strongyloides stercoralis at the low- and mid-dosage levels. At the high dosage level, good efficacy (91%) was observed only against S. stercoralis. Adverse reactions were observed in all dogs at every dosage level and included depression, ataxia, and protrusion of the nictitating membrane.