The Investigation / Parasitology 2025

The hookworms
in your dog park
just outsmarted
every dewormer.

A 2025 position paper from the American Association of Veterinary Parasitologists quietly confirmed what most dog owners have never been told: canine hookworms have evolved resistance to all three classes of approved anthelmintic drugs in the United States— and they've spread far beyond the greyhound farms where the problem started.

AAVP 2025

Multi-breed

Cornell CVM

U.S. & Canada

Parasites & Vectors

Wants it handled

3 / 3

Drug classes now failing

All

Breeds, ages, sizes affected

2 countries

USA + Canada confirmed

2025

AAVP position paper

Chapter 01

The story most dog owners have never heard.

For years, the veterinary world has whispered that dewormers are becoming "less effective." What didn't make it into the chat at your vet's office is the bombshell update buried in peer-reviewed parasitology journals:

Canine hookworms — Ancylostoma caninum — have now evolved resistance to all three classes of anthelmintic drugs approved in the United States.

This isn't a fringe finding. It's documented in Parasites & Vectors (December 2019), confirmed in the AAVP's June 2025 position paper in Veterinary Parasitology, and echoed in clinical reports from Cornell University College of Veterinary Medicine between 2022 and 2024.

Chapter 02

It didn't stay on the greyhound farms.

MADR originally evolved on greyhound breeding farms, where intense, repeated dosing created the perfect evolutionary pressure cooker. For a while, the assumption was that the problem would stay contained.

It didn't. The AAVP's 2025 position paper confirms MADR A. caninum has spread widely across the United States and into Canada, and is now being diagnosed in essentially any breed, any age, any size, any sex. Golden retrievers in suburban backyards. Apartment poodles. Rescues from the shelter. Puppies who've never been near a track.

Veterinary parasitologists are openly stating in the literature that they are "struggling" — and that even combination drug protocols are failing in newly diagnosed cases.

PULL QUOTE

"The reason your dog keeps getting reinfected isn't because you're doing something wrong. It's because the parasites themselves have evolved to survive pharmaceutical treatment."

Chapter 03

What parasitologists are quietly recommending now.

Nobody is suggesting you skip your annual dewormer. Veterinary medicine still matters. But the new conversation in clinical parasitology is about layered defense: pharmaceutical care for acute infection, and a daily gut-environment strategy that doesn't depend on the same three drug classes the worms have already learned to survive.

That's where Para Klens fits in. Not as a replacement for veterinary treatment — as the daily gut-defense layer underneath it. A way to support the body's natural intestinal environment so it's less hospitable to parasites, including the ones that have outsmarted the prescription pad.

The daily defense layer

Para Klens by Aavilo.

A daily gut-environment supplement designed for the post-MADR era. Built to sit underneath your vet's protocol — not in place of it.

- Daily gut-environment support — works with the body, not on the parasite

- Drug-class independent — not affected by anthelmintic resistance

- Safe to layer with your vet's existing protocol

- Made for every breed, every size, every age

Start the daily defense — Shop Para Klens

Disclaimer: Aavilo is a dietary supplement for companion animals, not a replacement for a balanced diet. Follow dosage instructions on aavilo.com. If your pet has medical conditions or is on medication, consult a veterinarian. This is an advertorial.