Reaction profile

The FDA adverse-event record for neck writhing

44 FDA adverse-event reports reference neck writhing (VeDDRA 2546). See the species, breeds, and drugs most associated with it below.

44
reports citing this reaction
15.9%
death-coded share
Dog
most-affected species
Milbemycin Oxime + Spinosad
most-associated drug
Verify with FDA CVM →
44
Total Reports
7
Deaths
15.9%
Death Rate

Species Most Affected

Dog 33
Horse 4
Cat 3
Cattle 3
Alpaca 1

Breeds Most Affected

Chihuahua 6
Domestic Shorthair 3
Crossbred Canine/dog 3
Terrier - West Highland White 2
Warmblood (unspecified) 2
Retriever - Labrador 2
Crossbred Bovine/Cattle 2
Bulldog 2
Corgi - Welsh Cardigan 2
Retriever - Golden 2

Associated Drugs

Milbemycin Oxime + Spinosad 10
Afoxolaner 8
Ceftiofur Crystalline Free Acid 3
Fluralaner 13.64% 12-Week Chew 2
Pyrantel Pamoate;Sarolaner 2
Melarsomine Dihydrochloride 2
Prednisone 2
Milbemycin/Lufenuron/Pzq Chew 2
Sarolaner 1
Dexamethasone 1
Diazepam 1
Clodronate Disodium 1
Firocoxib 1
Mirtazapine 1
Amoxicillin 1
Robenacoxib 1
Oclacitinib 1
Alprazolam 1
Butorphanol Tartrate 1
Milbemycin/Lufenuron Tablets 1

Neck writhing Reaction Insights

44 reports name Neck writhing; 7 recorded a death outcome (15.9% of reported events, not a population-level mortality rate). VeDDRA code: 2546.

By species: Dog (33 reports), Horse (4 reports), Cat (3 reports). By breed: Chihuahua (6), Domestic Shorthair (3), Crossbred Canine/dog (3).

Most co-reported drugs: Milbemycin Oxime + Spinosad (10 reports), Afoxolaner (8 reports), Ceftiofur Crystalline Free Acid (3 reports), Fluralaner 13.64% 12-Week Chew (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.