Reaction profile

The FDA adverse-event record for slow heart rate

180 FDA adverse-event reports reference slow heart rate (VeDDRA 190). Plate codes and volume neighbourhood below; species, breeds, and drugs follow.

#1091 of 2,481
by report volume (all reactions)
180
reports citing this reaction
17.8%
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. Slow heart rate has 180 reports now versus 176 in that prior snapshot: 4 more (2.3%).

Report change
+4
Death-coded reports
+0
Death-coded share
−0.4 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 Slow heart rate changes

FDA AER · VeDDRA plate

Code 190 VOL-LOW

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

  • VOL-LOW 180 reports
  • DEATH-ELEV 17.8%
  • MID-PACK #1091/2481
  • PHOTO-FINISH Mastitis NOS
  • SPECIES-DOG Dog · 145
  • DRUG-LEAD Milbemycin Oxime… · 30
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Mastitis NOS (±0 reports)

Instrument codes from this reaction’s FDA CVM adverse-event extract: volume band, death-coded share, corpus rank, photo-finish peer, lead species, lead drug, breed desk, and book completeness. Not a clinical diagnosis.

Report-volume neighbourhood around Slow heart rate

Highest and lowest poles plus nearest volume peers, not a full 2,500-reaction corpus board reprint.

Vomiting · highest174348Acidic urine · near181Mastitis NOS · near180Pigmentation disorder · near180Prolonged bleeding NOS · near180Slow heart rate · this react…180Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Slow heart rate

What the FDA AER plate says about Slow heart rate

Signature read: 32 death-coded reports is the most distinctive absolute-outcome stamp on Slow heart rate. Report volume sits in the middle third of the reaction corpus. 32 of 180 reports were death-coded (17.8% of named reports, not a population mortality rate). Nearest volume peer: Mastitis NOS (±0 reports). Lead species Dog (145). Lead co-reported drug Milbemycin Oxime + Spinosad (30).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Milbemycin Oxime + Spinosad 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 145
Cat 30
Human 2
Horse 2
Parrot 1

Breeds Most Affected

Domestic Shorthair 17
Retriever - Labrador 15
Dog (unknown) 10
Terrier - Yorkshire 10
Chihuahua 8
Shih Tzu 7
Crossbred Canine/dog 6
Dachshund (unspecified) 6
Cat (unknown) 5
Schnauzer - Miniature 5

Associated Drugs

Milbemycin Oxime + Spinosad 30
Isoflurane 17
Buprenorphine 15
Moxidectin 13
Dexmedetomidine Hydrochloride 13
Dexmedetomidine 11
Maropitant Citrate 11
Spinosad 9
Carprofen 8
Trilostane 8
Butorphanol 8
Ketamine 8
Milbemycin Oxime + Praziquantel 7
Atipamezole Hydrochloride 6
Rabies Vaccine 5
Meloxicam 5
Diazepam 5
Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On 4
Prednisone 4
Fluralaner Chew Tablets 4

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Slow 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 (180 here).

Similar death-coded share

Nearest other reactions by death-coded share (17.8% 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 Slow heart rate (#1091 of 2,481 by report volume); death-coded 17.8%. PlainBreed reaction plate · death-coded report count stamp 32 · 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 →