Reaction profile

The FDA adverse-event record for thrombocytosis

1,529 FDA reports name thrombocytosis, a high-volume reaction in the CVM extract (VeDDRA 2116). Plate stamps and neighbourhood peers follow.

#282 of 2,481
by report volume (all reactions)
1,529
reports citing this reaction
16.3%
death-coded share
Dog
most-affected species

Release-over-release change

What changed in the latest FDA data snapshot

PlainBreed reconstructed the prior snapshot from dated openFDA partitions through 2025 Q4, then compared it with the 2026-07-27 openFDA export. Thrombocytosis has 1,529 reports now versus 1,464 in that prior snapshot: 65 more (4.4%).

Report change
+65
Death-coded reports
+9
Death-coded share
−0.1 pts

This compares reported-event counts in two source snapshots. It does not establish a change in real-world risk, product safety, or disease incidence.

Subscribe to Thrombocytosis changes

FDA AER · VeDDRA plate

Code 2116 VOL-MID

VOL-MID · DEATH-ELEV · UPPER-Q · PHOTO-FINISH · SPECIES-DOG · DRUG-LEAD · DESK-WIDE · BOOK-FULL

  • VOL-MID 1,529 reports
  • DEATH-ELEV 16.3%
  • UPPER-Q #282/2481
  • PHOTO-FINISH Allergic reaction
  • SPECIES-DOG Dog · 1,450
  • DRUG-LEAD Trilostane · 640
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Allergic reaction (±1 reports)

Upper-third report volume drives the scale stamps on this plate; death-coded share and co-report peers follow. Not a clinical diagnosis.

High-volume neighbourhood around Thrombocytosis

Upper-third volume poles plus nearest peers, not a full reaction corpus board reprint.

Vomiting · highest174348Increased respiratory… · near1534Contamination, Foreig… · near1531Staring · near1531Thrombocytosis · this reacti…1529Allergic reaction · near1528Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Thrombocytosis

What the FDA AER plate says about Thrombocytosis

Signature read: 249 death-coded reports is a heavy tail count for Thrombocytosis in the CVM extract. Report volume is upper-third scale: 1,529 named reports in the openFDA extract. 249 of 1,529 reports were death-coded (16.3% of named reports, not a population mortality rate). Nearest volume peer: Allergic reaction (±1 reports). Lead species Dog (1,450). Lead co-reported drug Trilostane (640).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Trilostane appears in filings alongside this reaction; that is association, not causation. Browse the full reactions index or the about page for how PlainBreed frames FDA CVM extracts.

Species Most Affected

Dog 1,450
Cat 72
Horse 4
Other Canids 1
Cattle 1
Wolf 1

Breeds Most Affected

Chihuahua 122
Shih Tzu 117
Retriever - Labrador 81
Crossbred Canine/dog 73
Maltese 66
Terrier - Yorkshire 57
Terrier - Boston 53
Terrier (unspecified) 44
Domestic Shorthair 42
Beagle 37

Associated Drugs

Trilostane 640
Milbemycin Oxime + Spinosad 115
Carprofen 107
Oclacitinib Maleate 98
Bedinvetmab 97
Gabapentin 92
Maropitant Citrate 85
Afoxolaner 78
Spinosad 70
Fluralaner Chew Tablets 64
Grapiprant 64
Ivermectin + Pyrantel As Pamoate Salt 52
Meloxicam 50
Cyclosporine 49
Prednisone 46
Fluralaner 13.64% 12-Week Chew 34
Pimobendan 33
Milbemycin Oxime + Praziquantel 33
Metronidazole 32
Polysulfated Glycosaminoglycan 31

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Thrombocytosis, both floored at ≥50 reports so the neighborhoods stay in the advertised mass (the volume chart above is the unfloored photo-finish strip).

Similar report volume

Nearest other reactions by FDA report count (1,529 here).

Similar death-coded share

Nearest other reactions by death-coded share (16.3% here), distinct from the volume row.

What to do with this reaction

A report does not prove a drug caused the reaction; consult a veterinarian before acting on this data.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

openFDA Animal & Veterinary Adverse Events (FDA CVM) for Thrombocytosis (#282 of 2,481 by report volume); death-coded 16.3%. PlainBreed reaction plate · death-coded report count stamp 249 · vintage 2025.

Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →