Reaction profile

The FDA adverse-event record for monocytosis

2,414 FDA adverse-event reports reference monocytosis (VeDDRA 2420). See the species, breeds, and drugs most associated with it below.

2,414
reports citing this reaction
29.2%
death-coded share
Dog
most-affected species
Carprofen
most-associated drug
Verify with FDA CVM →
2,414
Total Reports
705
Deaths
29.2%
Death Rate

Species Most Affected

Dog 2,019
Cat 377
Horse 16
Cattle 2

Breeds Most Affected

Retriever - Labrador 264
Domestic Shorthair 238
Crossbred Canine/dog 164
Shepherd Dog - German 111
Retriever - Golden 100
Shih Tzu 74
Chihuahua 70
Terrier - Yorkshire 52
Pug 46
Terrier (unspecified) 45

Associated Drugs

Carprofen 285
Maropitant Citrate 273
Afoxolaner 195
Bedinvetmab 133
Gabapentin 130
Fluralaner Chew Tablets 129
Ivermectin + Pyrantel As Pamoate Salt 126
Prednisone 121
Oclacitinib Maleate 119
Meloxicam 102
Milbemycin Oxime + Spinosad 101
Trilostane 98
Moxidectin 96
Cefovecin 89
Enrofloxacin 85
Famotidine 83
Metronidazole 81
Doxycycline 78
Buprenorphine 76
Fluralaner 13.64% 12-Week Chew 63

Monocytosis Reaction Insights

2,414 reports name Monocytosis; 705 recorded a death outcome (29.2% of reported events, not a population-level mortality rate). VeDDRA code: 2420.

By species: Dog (2,019 reports), Cat (377 reports), Horse (16 reports). By breed: Retriever - Labrador (264), Domestic Shorthair (238), Crossbred Canine/dog (164).

Most co-reported drugs: Carprofen (285 reports), Maropitant Citrate (273 reports), Afoxolaner (195 reports), Bedinvetmab (133 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.