Reaction profile

The FDA adverse-event record for muscle rigidity

191 FDA adverse-event reports reference muscle rigidity (VeDDRA 1628). Plate codes and volume neighbourhood below; species, breeds, and drugs follow.

#1066 of 2,481
by report volume (all reactions)
191
reports citing this reaction
18.3%
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. Muscle rigidity has 191 reports now versus 190 in that prior snapshot: 1 more (0.5%).

Report change
+1
Death-coded reports
+0
Death-coded share
−0.1 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 Muscle rigidity changes

FDA AER · VeDDRA plate

Code 1628 VOL-LOW

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

  • VOL-LOW 191 reports
  • DEATH-ELEV 18.3%
  • MID-PACK #1066/2481
  • PHOTO-FINISH Bloody stool
  • SPECIES-DOG Dog · 162
  • DRUG-LEAD Afoxolaner · 27
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Bloody stool (±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.

Report-volume neighbourhood around Muscle rigidity

Highest and lowest poles plus nearest volume peers, not a full 2,500-reaction corpus board reprint.

Vomiting · highest174348Bloody stool · near191Decreased pulse oxyge… · near191Dizziness · near191Enlarged kidney(s) · near191Muscle rigidity · this react…191Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Muscle rigidity

What the FDA AER plate says about Muscle rigidity

Signature read: 35 death-coded reports is the most distinctive absolute-outcome stamp on Muscle rigidity. Report volume sits in the middle third of the reaction corpus. 35 of 191 reports were death-coded (18.3% of named reports, not a population mortality rate). Nearest volume peer: Bloody stool (±0 reports). Lead species Dog (162). Lead co-reported drug Afoxolaner (27).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Afoxolaner 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 162
Cat 20
Horse 7
Cattle 2

Breeds Most Affected

Chihuahua 16
Retriever - Labrador 14
Crossbred Canine/dog 13
Shih Tzu 12
Domestic Shorthair 9
Dog (unknown) 6
Maltese 5
Shepherd Dog - Australian 5
Quarter Horse 4
Spaniel - King Charles Cavalier 4

Associated Drugs

Afoxolaner 27
Milbemycin Oxime + Spinosad 18
Ivermectin + Pyrantel As Pamoate Salt 18
Carprofen 15
Isoflurane 14
Fluralaner Chew Tablets 11
Propofol 11
Alfaxalone 9
Lotilaner 8
Gabapentin 8
Midazolam 7
Bedinvetmab 7
Spinosad 6
Oclacitinib Maleate 6
Maropitant Citrate 6
Fluralaner 13.64% 12-Week Chew 6
Pyrantel Pamoate;Sarolaner 6
Imidacloprid + Moxidectin 5
Hydromorphone 5
Dexmedetomidine Hydrochloride 5

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Muscle rigidity, both floored at ≥50 reports so the neighborhoods stay in the advertised mass (the volume chart above is the unfloored photo-finish strip).

Similar report volume

Nearest other reactions by FDA report count (191 here).

Similar death-coded share

Nearest other reactions by death-coded share (18.3% here), distinct from the volume row.

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 Muscle rigidity (#1066 of 2,481 by report volume); death-coded 18.3%. PlainBreed reaction plate · death-coded report count stamp 35 · 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 →