Reaction profile

The FDA adverse-event record for myoclonus

40 FDA reports name myoclonus, a lower-volume reaction in the CVM extract (VeDDRA 650). Plate stamps and neighbourhood peers follow.

#1848 of 2,481
by report volume (all reactions)
40
reports citing this reaction
17.5%
death-coded share
Dog
most-affected species

Release-over-release change

What changed in the latest FDA data snapshot

PlainBreed reconstructed the prior snapshot from dated openFDA partitions through 2025 Q4, then compared it with the 2026-07-27 openFDA export. Myoclonus has 40 reports now versus 39 in that prior snapshot: 1 more (2.6%).

Report change
+1
Death-coded reports
+1
Death-coded share
+2.1 pts

This compares reported-event counts in two source snapshots. It does not establish a change in real-world risk, product safety, or disease incidence.

Subscribe to Myoclonus changes

FDA AER · VeDDRA plate

Code 650 VOL-TRACE

VOL-TRACE · DEATH-ELEV · MID-PACK · PHOTO-FINISH · SPECIES-DOG · DRUG-LEAD · DESK-WIDE · BOOK-FULL

  • VOL-TRACE 40 reports
  • DEATH-ELEV 17.5%
  • MID-PACK #1848/2481
  • PHOTO-FINISH Acute (interstitial)…
  • SPECIES-DOG Dog · 36
  • DRUG-LEAD Propofol · 6
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Acute (interstitial) pneumonia/pleuropneumonia (±0 reports)

Instrument codes from this reaction’s FDA CVM adverse-event extract: volume band, death-coded share, corpus rank, photo-finish peer, lead species, lead drug, breed desk, and book completeness. Not a clinical diagnosis.

Lower-volume neighbourhood around Myoclonus

Lower-third volume poles plus nearest peers, not a full reaction corpus board reprint.

Vomiting · highest174348Acute (interstitial)… · near40Anxious state of mind · near40Direct Coombs test, p… · near40Endocrine neoplasm · near40Myoclonus · this reaction40Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Myoclonus

What the FDA AER plate says about Myoclonus

Signature read: 40 reports place Myoclonus in the lower third of FDA AER volume (#1848 of 2,481). Report volume is lower-third scale: 40 named reports in the openFDA extract. 7 of 40 reports were death-coded (17.5% of named reports, not a population mortality rate). Nearest volume peer: Acute (interstitial) pneumonia/pleuropneumonia (±0 reports). Lead species Dog (36). Lead co-reported drug Propofol (6).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Propofol appears in filings alongside this reaction; that is association, not causation. Browse the full reactions index or the about page for how PlainBreed frames FDA CVM extracts.

Species Most Affected

Dog 36
Cat 4

Breeds Most Affected

Beagle 4
Terrier (unspecified) 3
Chihuahua 2
Domestic Shorthair 2
Terrier - Yorkshire 2
Shepherd Dog - German 2
Crossbred Canine/dog 2
Poodle - Standard 2
Boxer (German Boxer) 1
Terrier - West Highland White 1

Associated Drugs

Propofol 6
Alfaxalone 6
Sarolaner 4
Sevoflurane 4
Bedinvetmab 4
Enrofloxacin 3
Midazolam Hydrochloride 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
Cefazolin 2
Butorphanol 2
Buprenorphine 2
Fluralaner 2
Pyrantel Pamoate;Sarolaner 2
Fluralaner 13.64% 12-Week Chew 2

What to do with this reaction

A report does not prove a drug caused the reaction; consult a veterinarian before acting on this data.

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

openFDA Animal & Veterinary Adverse Events (FDA CVM) for Myoclonus (#1848 of 2,481 by report volume); death-coded 17.5%. PlainBreed reaction plate · report volume stamp 40 · vintage 2025.

Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →