Reaction profile

The FDA adverse-event record for myoclonus

38 FDA adverse-event reports reference myoclonus (VeDDRA 650). See the species, breeds, and drugs most associated with it below.

38
reports citing this reaction
15.8%
death-coded share
Dog
most-affected species
Propofol
most-associated drug
Verify with FDA CVM →
38
Total Reports
6
Deaths
15.8%
Death Rate

Species Most Affected

Dog 34
Cat 4

Breeds Most Affected

Beagle 4
Chihuahua 2
Domestic Shorthair 2
Terrier - Yorkshire 2
Shepherd Dog - German 2
Terrier (unspecified) 2
Crossbred Canine/dog 2
Poodle - Standard 2
Boxer (German Boxer) 1
Terrier - West Highland White 1

Associated Drugs

Propofol 6
Alfaxalone 6
Sevoflurane 4
Enrofloxacin 3
Midazolam Hydrochloride 3
Sarolaner 3
Bedinvetmab 3
Canine Adenovirus Type 2, Strain Manhattan, 12-13-76; Canine Distemper Virus, St 2
Maropitant Citrate 2
Selamectin 2
Moxidectin 2
Afoxolaner 28.3 Mg Chewable Tablets 2
Hydromorphone Hcl 2
Isoflurane 2
Butorphanol 2
Buprenorphine 2
Fluralaner 2
Fluralaner 13.64% 12-Week Chew 2
Hydromorphone 2
Midazolam 2

Myoclonus Reaction Insights

38 reports name Myoclonus; 6 recorded a death outcome (15.8% of reported events, not a population-level mortality rate). VeDDRA code: 650.

By species: Dog (34 reports), Cat (4 reports). By breed: Beagle (4), Chihuahua (2), Domestic Shorthair (2).

Most co-reported drugs: Propofol (6 reports), Alfaxalone (6 reports), Sevoflurane (4 reports), Enrofloxacin (3 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.