Reaction profile

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

6,881 FDA adverse-event reports reference lack of efficacy (endoparasite) - whipworm (VeDDRA 2801). See the species, breeds, and drugs most associated with it below.

6,881
reports citing this reaction
1.1%
death-coded share
Dog
most-affected species
Ivermectin + Pyrantel As Pamoate Salt
most-associated drug
Verify with FDA CVM →
6,881
Total Reports
73
Deaths
1.1%
Death Rate

Species Most Affected

Dog 6,857
Cat 9
Cattle 9
Sheep 1
Primate 1
Other 1
Camel 1
Pig 1
Horse 1

Breeds Most Affected

Retriever - Labrador 749
Crossbred Canine/dog 697
Retriever - Golden 454
Shepherd Dog - German 312
Beagle 311
Dachshund (unspecified) 197
Shepherd Dog - Australian 187
Dog (unknown) 185
Collie - Border 152
Schnauzer - Miniature 136

Associated Drugs

Ivermectin + Pyrantel As Pamoate Salt 1,028
Milbemycin Oxime + Spinosad 862
Moxidectin 816
Pyrantel Pamoate;Sarolaner 796
Milbemycin 566
Milbemycin Oxime + Praziquantel 482
Milbemycin Oxime, Lufenuron 424
Selamectin 302
Lufenuron + Milbemycin Oxime 239
Milbemycin Oxime 229
Imidacloprid + Moxidectin 192
Milbemcyin Oxime, Lufenuron, Praziquantel 157
Milbemycin, Lufenuron 124
Milbemycin/Lufenuron/Pzq Chew 121
Ivermectin, Pyrantel 103
Ivermectin/Pyrantel Pamoate Chewable 272Mcg/652Mg 103
Milbemycin/Lufenuron Tablets 95
Ivermectin/Pyrantel Pamoate Chewable 68Mcg/163Mg 62
Ivermectin/Pyrantel Pamoate Chewable 136Mcg/326Mg 57
Fenbendazole 50

Lack of efficacy (endoparasite) - whipworm Reaction Insights

6,881 reports name Lack of efficacy (endoparasite) - whipworm; 73 recorded a death outcome (1.1% of reported events, not a population-level mortality rate). VeDDRA code: 2801.

By species: Dog (6,857 reports), Cat (9 reports), Cattle (9 reports). By breed: Retriever - Labrador (749), Crossbred Canine/dog (697), Retriever - Golden (454).

Most co-reported drugs: Ivermectin + Pyrantel As Pamoate Salt (1,028 reports), Milbemycin Oxime + Spinosad (862 reports), Moxidectin (816 reports), Pyrantel Pamoate;Sarolaner (796 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.