Veterinary parasitologists warn that multidrug-resistant hookworms are spreading in the U.S. and veterinarians should watch for persistent infections. Antoinette Marsh, PhD, cited study results that indicate dogs with suspected or confirmed drug-resistant hookworms are becoming widespread in the Southeast, and they have been documented in the Northeast and California. She said not all of the isolates are multidrug resistant.
Marsh said drug resistance in hookworms likely developed through misuse of anthelmintics approved for administration to livestock. Some of those products contain the same active ingredients as prescription anthelmintics intended for dogs, but in different formulations and sometimes different routes of administration.
Source: JAVMA, September 15, 2021. Link.
When veterinarians use a dewormer, particularly in a dog with documented infection, it’s important to retest that dog 10-14 days later to ensure the dog is no longer shedding eggs or it has significant reduction in fecal egg counts following deworming. It is recommended to monitor as long as shedding persists.” – Antoinette Marsh, PhD
Also see: Parasite prevalence maps, CAPC, July 2021. Link.