Reaction profile

The FDA adverse-event record for decreased heart rate

424 FDA reports name decreased heart rate, a high-volume reaction in the CVM extract (VeDDRA 189). Plate stamps and neighbourhood peers follow.

#703 of 2,481
by report volume (all reactions)
424
reports citing this reaction
19.6%
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. Decreased heart rate has 424 reports now versus 409 in that prior snapshot: 15 more (3.7%).

Report change
+15
Death-coded reports
+1
Death-coded share
−0.5 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 Decreased heart rate changes

FDA AER · VeDDRA plate

Code 189 VOL-LOW

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

  • VOL-LOW 424 reports
  • DEATH-ELEV 19.6%
  • MID-PACK #703/2481
  • PHOTO-FINISH Anuria
  • SPECIES-DOG Dog · 326
  • DRUG-LEAD Dexmedetomidine H… · 59
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Anuria (±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 Decreased heart rate

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

Vomiting · highest174348Lip oedema (see also… · near425Shallow breathing · near425Decreased heart rate · this …424Anuria · near423Decreased percentage… · near423Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Decreased heart rate

What the FDA AER plate says about Decreased heart rate

Signature read: 83 death-coded reports is a heavy tail count for Decreased heart rate in the CVM extract. Report volume is upper-third scale: 424 named reports in the openFDA extract. 83 of 424 reports were death-coded (19.6% of named reports, not a population mortality rate). Nearest volume peer: Anuria (±1 reports). Lead species Dog (326). Lead co-reported drug Dexmedetomidine Hydrochloride (59).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Dexmedetomidine Hydrochloride 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 326
Cat 86
Human 6
Horse 3
Chinchilla 1
Mouse 1
Rabbit 1

Breeds Most Affected

Domestic Shorthair 53
Chihuahua 31
Retriever - Labrador 24
Dog (unknown) 21
Shih Tzu 16
Terrier - Yorkshire 15
Shepherd Dog - German 14
Maltese 11
Crossbred Canine/dog 11
Unknown 11

Associated Drugs

Dexmedetomidine Hydrochloride 59
Isoflurane 58
Maropitant Citrate 50
Propofol 39
Dexmedetomidine 39
Buprenorphine 38
Moxidectin 30
Milbemycin Oxime + Spinosad 29
Atipamezole Hydrochloride 28
Butorphanol 27
Carprofen 26
Butorphanol Tartrate 26
Ketamine 26
Capromorelin 26
Gabapentin 24
Epinephrine 19
Midazolam 19
Hydromorphone 15
Ketamine Hydrochloride 14
Atropine 12

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Decreased heart rate, 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 (424 here).

Similar death-coded share

Nearest other reactions by death-coded share (19.6% 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 Decreased heart rate (#703 of 2,481 by report volume); death-coded 19.6%. PlainBreed reaction plate · death-coded report count stamp 83 · 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 →