American Association of Veterinary Parasitologists Hookworm Task Force review on best practices for diagnosis and treatment of multidrug-resistant hookworms

Ancylostoma caninum, the canine hookworm, is the most common and clinically important gastrointestinal nematode parasite infecting dogs in the US. Common clinical signs associated with acute infections include anemia, melena, hematochezia, dehydration, and poor weight gain or weight loss. In the past few years, multiple anthelmintic drug resistance to fenbendazole, moxidectin, and pyrantel pamoate has been documented in A caninum in the US, and cases of drug-resistant canine hookworms are increasingly being reported in the US and Canada. Clinical and genetic evidence strongly suggests that multiple anthelmintic drug-resistant A caninum likely originated on Greyhound breeding farms and kennels. However, the problem is no longer restricted to Greyhounds; several large national studies have shown that drug-resistant A caninum was present in dogs of all sizes, ages, and breeds and at varying but always high prevalence in every region of the continental US. The high prevalence and wide distribution of drug-resistant hookworms present a matter of urgent concern for veterinarians in North America and elsewhere. In response to this concern, the American Association of Veterinary Parasitologists established a Hookworm Task Force in 2021, and this paper is a result of the work of that task force. Here we provide guidance on best practices for diagnosis, treatment, and management of drug-resistant hookworm cases and summarize relevant studies to help veterinarians understand what is known about the biology, prevalence, and epidemiology of these parasites.