Reaction profile

The FDA adverse-event record for tonic muscle spasm

21 FDA adverse-event reports reference tonic muscle spasm (VeDDRA 1140). See the species, breeds, and drugs most associated with it below.

21
reports citing this reaction
33.3%
death-coded share
Dog
most-affected species
Spinosad
most-associated drug
Verify with FDA CVM →
21
Total Reports
7
Deaths
33.3%
Death Rate

Species Most Affected

Dog 16
Cat 4
Mouse 1

Breeds Most Affected

Crossbred Canine/dog 2
Chihuahua 2
Retriever - Labrador 2
Domestic Longhair 1
Domestic Mediumhair 1
Ragdoll 1
Boxer (German Boxer) 1
Doberman Pinscher 1
Retriever - Chesapeake Bay 1
Schnauzer (unspecified) 1

Associated Drugs

Spinosad 4
Trilostane 3
Fluralaner Chew Tablets 3
Pimobendan 3
Ivermectin + Pyrantel As Pamoate Salt 2
Sarolaner 2
Propofol 2
Butorphanol 2
Dexmedetomidine 2
Flea Product (Unknown) 1
Vaccines (Unknown) 1
Dexamethasone 1
Selamectin 1
Milbemycin Oxime + Spinosad 1
Benazepril 1
Same 1
Moxidectin 1
Rabies Vaccine 1
Dhppl Vaccine 1
Bordetella Vaccine 1

Tonic muscle spasm Reaction Insights

21 reports name Tonic muscle spasm; 7 recorded a death outcome (33.3% of reported events, not a population-level mortality rate). VeDDRA code: 1140.

By species: Dog (16 reports), Cat (4 reports), Mouse (1 reports). By breed: Crossbred Canine/dog (2), Chihuahua (2), Retriever - Labrador (2).

Most co-reported drugs: Spinosad (4 reports), Trilostane (3 reports), Fluralaner Chew Tablets (3 reports), Pimobendan (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.