Reaction profile

The FDA adverse-event record for somnolence

400 FDA adverse-event reports reference somnolence (VeDDRA 110). See the species, breeds, and drugs most associated with it below.

400
reports citing this reaction
9.5%
death-coded share
Dog
most-affected species
Milbemycin Oxime + Spinosad
most-associated drug
Verify with FDA CVM →
400
Total Reports
38
Deaths
9.5%
Death Rate

Species Most Affected

Dog 328
Cat 62
Horse 4
Cattle 3
Chicken 2
Human 1

Breeds Most Affected

Crossbred Canine/dog 32
Retriever - Labrador 27
Retriever - Golden 20
Domestic (unspecified) 20
Domestic Shorthair 19
Boxer (German Boxer) 17
Chihuahua 16
Shih Tzu 13
Spitz - German Pomeranian 12
Poodle (unspecified) 11

Associated Drugs

Milbemycin Oxime + Spinosad 101
Spinosad 40
Ivermectin 15
Carprofen 13
Maropitant 11
Oclacitinib Maleate 11
Afoxolaner 10
Maropitant Citrate 9
Gabapentin 9
Nitenpyram 8
Cyclosporine 8
Buprenorphine 8
Ivermectin + Pyrantel As Pamoate Salt 7
Fluralaner Chew Tablets 7
Grapiprant 7
Pyrantel Pamoate;Sarolaner 7
Firocoxib 6
Fenbendazole 6
Imidacloprid, Moxidectin 6
Cefovecin Sodium 6

Somnolence Reaction Insights

400 reports name Somnolence; 38 recorded a death outcome (9.5% of reported events, not a population-level mortality rate). VeDDRA code: 110.

By species: Dog (328 reports), Cat (62 reports), Horse (4 reports). By breed: Crossbred Canine/dog (32), Retriever - Labrador (27), Retriever - Golden (20).

Most co-reported drugs: Milbemycin Oxime + Spinosad (101 reports), Spinosad (40 reports), Ivermectin (15 reports), Carprofen (13 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.