Reaction profile

The FDA adverse-event record for heart block 2nd degree

58 FDA reports name heart block 2nd degree, a lower-volume reaction in the CVM extract (VeDDRA 2432). Plate stamps and neighbourhood peers follow.

#1666 of 2,481
by report volume (all reactions)
58
reports citing this reaction
12.1%
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. Heart block 2nd degree has 58 reports now versus 54 in that prior snapshot: 4 more (7.4%).

Report change
+4
Death-coded reports
+0
Death-coded share
−0.9 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 Heart block 2nd degree changes

FDA AER · VeDDRA plate

Code 2432 VOL-LOW

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

  • VOL-LOW 58 reports
  • DEATH-ELEV 12.1%
  • MID-PACK #1666/2481
  • PHOTO-FINISH Muscle degeneration
  • SPECIES-DOG Dog · 49
  • DRUG-LEAD Dexmedetomidine H… · 26
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Muscle degeneration (±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.

Lower-volume neighbourhood around Heart block 2nd degree

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

Vomiting · highest174348Heart block 2nd degree · thi…58Muscle degeneration · near58Ocular burn · near58Painful urination · near58PR-BONE MARROW, LESIO… · near58Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Heart block 2nd degree

What the FDA AER plate says about Heart block 2nd degree

Signature read: 7 death-coded reports is a thin tail count for Heart block 2nd degree in the CVM extract. Report volume is lower-third scale: 58 named reports in the openFDA extract. 7 of 58 reports were death-coded (12.1% of named reports, not a population mortality rate). Nearest volume peer: Muscle degeneration (±0 reports). Lead species Dog (49). Lead co-reported drug Dexmedetomidine Hydrochloride (26).

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 49
Horse 5
Cat 2
Ferret 1
Pigeon 1

Breeds Most Affected

Dog (unknown) 6
Retriever - Labrador 6
Unknown 3
Terrier - Yorkshire 3
Mixed (Dog) 3
Terrier - Bull - American Pit 2
Schnauzer - Miniature 2
Terrier - West Highland White 2
Thoroughbred 2
Collie - Border 2

Associated Drugs

Dexmedetomidine Hydrochloride 26
Atipamezole Hydrochloride 6
Butorphanol Tartrate 5
Butorphanol 5
Dexmedetomidine 5
Detomidine Hydrochloride 4
Buprenorphine 4
Fluralaner Chew Tablets 3
Propofol 3
Anesthetic 3
Maropitant Citrate 3
Moxidectin 3
Hydromorphone 3
Canine Cough Syrup 3
Midazolam 3
Carprofen 2
Cefazolin 2
Hydromorphone Hcl 2
Isoflurane 2
Pimobendan 2

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Heart block 2nd degree, 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 (58 here).

Similar death-coded share

Nearest other reactions by death-coded share (12.1% 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 Heart block 2nd degree (#1666 of 2,481 by report volume); death-coded 12.1%. PlainBreed reaction plate · death-coded report count stamp 7 · 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 →