Reaction profile

The FDA adverse-event record for lack of efficacy (endoparasite) - hookworm

40,229 FDA adverse-event reports reference lack of efficacy (endoparasite) - hookworm (VeDDRA 2798). See the species, breeds, and drugs most associated with it below.

40,229
reports citing this reaction
0.3%
death-coded share
Dog
most-affected species
Ivermectin + Pyrantel As Pamoate Salt
most-associated drug
Verify with FDA CVM →
40,229
Total Reports
102
Deaths
0.3%
Death Rate

Species Most Affected

Dog 40,060
Cat 161
Cattle 4
Other 1
Cougar 1
Wolf 1
Deer 1

Breeds Most Affected

Retriever - Labrador 5,726
Crossbred Canine/dog 3,866
Retriever - Golden 2,976
Beagle 1,654
Shepherd Dog - German 1,556
Greyhound 1,322
Dog (unknown) 979
Boxer (German Boxer) 892
Shepherd Dog - Australian 834
Shih Tzu 814

Associated Drugs

Ivermectin + Pyrantel As Pamoate Salt 13,580
Moxidectin 3,791
Pyrantel Pamoate;Sarolaner 3,730
Milbemycin Oxime + Spinosad 3,160
Milbemycin Oxime + Praziquantel 2,336
Ivermectin, Pyrantel 2,185
Milbemycin Oxime, Lufenuron 1,406
Ivermectin/Pyrantel Pamoate Chewable 272Mcg/652Mg 1,376
Selamectin 927
Ivermectin/Pyrantel Pamoate Chewable 68Mcg/163Mg 881
Ivermectin/Pyrantel Pamoate Chewable 136Mcg/326Mg 727
Milbemycin 638
Milbemycin/Lufenuron/Pzq Chew 630
Ivermectin + Pyrantel 604
Milbemycin/Lufenuron Tablets 552
Milbemcyin Oxime, Lufenuron, Praziquantel 549
Lufenuron + Milbemycin Oxime 504
Milbemycin Oxime 484
Imidacloprid + Moxidectin 314
Afoxolaner 300

Lack of efficacy (endoparasite) - hookworm Reaction Insights

40,229 reports name Lack of efficacy (endoparasite) - hookworm; 102 recorded a death outcome (0.3% of reported events, not a population-level mortality rate). VeDDRA code: 2798.

By species: Dog (40,060 reports), Cat (161 reports), Cattle (4 reports). By breed: Retriever - Labrador (5,726), Crossbred Canine/dog (3,866), Retriever - Golden (2,976).

Most co-reported drugs: Ivermectin + Pyrantel As Pamoate Salt (13,580 reports), Moxidectin (3,791 reports), Pyrantel Pamoate;Sarolaner (3,730 reports), Milbemycin Oxime + Spinosad (3,160 reports).

Read these counts as reporting volume, not risk: per our methodology, co-reporting reflects temporal association captured in voluntary submissions, not proof that a drug caused this reaction. A widely-prescribed drug will rack up more raw co-reports at an identical true rate than a rarely-used one, so compare within similar-exposure products.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.