Reaction profile

The FDA adverse-event record for clonic muscle spasm

19 FDA adverse-event reports reference clonic muscle spasm (VeDDRA 1139). See the species, breeds, and drugs most associated with it below.

19
reports citing this reaction
10.5%
death-coded share
Dog
most-affected species
Spinosad
most-associated drug
Verify with FDA CVM →
19
Total Reports
2
Deaths
10.5%
Death Rate

Species Most Affected

Dog 15
Cat 3
Human 1

Breeds Most Affected

Retriever - Labrador 4
Spaniel - King Charles Cavalier 2
Domestic Longhair 1
Griffon (unspecified) 1
Chihuahua 1
Pinscher - Miniature 1
Domestic Mediumhair 1
Unknown 1
Collie - Border 1
Crossbred Canine/dog 1

Associated Drugs

Spinosad 3
Alfaxalone 3
Milbemycin Oxime + Spinosad 2
Moxidectin 2
Dexamethasone 2
Afoxolaner 2
Ivermectin + Pyrantel As Pamoate Salt 2
Flea Product (Unknown) 1
Vaccines (Unknown) 1
Selamectin 1
Enrofloxacin 1
Imidocarb Dipropionate Inj Sol 1
Rabies Vaccine 1
Dhppl Vaccine 1
Bordetella Vaccine 1
Butorphanol 1
Acepromazine 1
Isoflurane 1
Meloxicam 1
Buprenorphine 1

Clonic muscle spasm Reaction Insights

19 reports name Clonic muscle spasm; 2 recorded a death outcome (10.5% of reported events, not a population-level mortality rate). VeDDRA code: 1139.

By species: Dog (15 reports), Cat (3 reports), Human (1 reports). By breed: Retriever - Labrador (4), Spaniel - King Charles Cavalier (2), Domestic Longhair (1).

Most co-reported drugs: Spinosad (3 reports), Alfaxalone (3 reports), Milbemycin Oxime + Spinosad (2 reports), Moxidectin (2 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.