Reaction profile

The FDA adverse-event record for extensor rigidity

117 FDA adverse-event reports reference extensor rigidity (VeDDRA 1127). See the species, breeds, and drugs most associated with it below.

117
reports citing this reaction
29.1%
death-coded share
Dog
most-affected species
Alfaxalone
most-associated drug
Verify with FDA CVM →
117
Total Reports
34
Deaths
29.1%
Death Rate

Species Most Affected

Dog 93
Cat 24

Breeds Most Affected

Domestic Shorthair 13
Retriever - Labrador 12
Chihuahua 8
Crossbred Canine/dog 8
Boxer (German Boxer) 7
Shih Tzu 7
Pug 4
Retriever - Golden 4
Dachshund (unspecified) 4
Cat (unknown) 3

Associated Drugs

Alfaxalone 14
Afoxolaner 13
Ivermectin + Pyrantel As Pamoate Salt 9
Milbemycin Oxime + Spinosad 8
Carprofen 8
Fluralaner Chew Tablets 8
Maropitant Citrate 6
Butorphanol 6
Buprenorphine 6
Pyrantel Pamoate;Sarolaner 6
Moxidectin 5
Selamectin 4
Cefovecin 4
Dexmedetomidine 4
Fluralaner 13.64% 12-Week Chew 4
Bedinvetmab 4
Propofol 3
Spinosad 3
Ivermectin 3
Doxycycline 3

Extensor rigidity Reaction Insights

117 reports name Extensor rigidity; 34 recorded a death outcome (29.1% of reported events, not a population-level mortality rate). VeDDRA code: 1127.

By species: Dog (93 reports), Cat (24 reports). By breed: Domestic Shorthair (13), Retriever - Labrador (12), Chihuahua (8).

Most co-reported drugs: Alfaxalone (14 reports), Afoxolaner (13 reports), Ivermectin + Pyrantel As Pamoate Salt (9 reports), Milbemycin Oxime + Spinosad (8 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.