Reaction profile

The FDA adverse-event record for increased seizure frequency

305 FDA adverse-event reports reference increased seizure frequency (VeDDRA 2528). Plate codes and volume neighbourhood below; species, breeds, and drugs follow.

#863 of 2,481
by report volume (all reactions)
305
reports citing this reaction
12.5%
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. Increased seizure frequency has 305 reports now versus 298 in that prior snapshot: 7 more (2.3%).

Report change
+7
Death-coded reports
+0
Death-coded share
−0.3 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 Increased seizure frequency changes

FDA AER · VeDDRA plate

Code 2528 VOL-LOW

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

  • VOL-LOW 305 reports
  • DEATH-ELEV 12.5%
  • MID-PACK #863/2481
  • PHOTO-FINISH Increased bowel movem…
  • SPECIES-DOG Dog · 292
  • DRUG-LEAD Phenobarbital · 62
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Increased bowel movements (frequency) (±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 Increased seizure frequency

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

Vomiting · highest174348Blood in faeces NOS · near307Dermal thickening · near306Swollen tongue · near306Increased bowel movem… · near305Increased seizure fre… · thi…305Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Increased seizure frequency

What the FDA AER plate says about Increased seizure frequency

Signature read: 38 death-coded reports is the most distinctive absolute-outcome stamp on Increased seizure frequency. Report volume sits in the middle third of the reaction corpus. 38 of 305 reports were death-coded (12.5% of named reports, not a population mortality rate). Nearest volume peer: Increased bowel movements (frequency) (±0 reports). Lead species Dog (292). Lead co-reported drug Phenobarbital (62).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Phenobarbital 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 292
Cat 12
Rabbit 1

Breeds Most Affected

Crossbred Canine/dog 25
Retriever - Labrador 24
Retriever - Golden 17
Shepherd Dog - German 14
Chihuahua 14
Shih Tzu 13
Boxer (German Boxer) 12
Cattle Dog - Australian (blue heeler, red heeler, Queensland cattledog) 12
Siberian Husky 10
Terrier (unspecified) 9

Associated Drugs

Phenobarbital 62
Pyrantel Pamoate;Sarolaner 43
Oclacitinib Maleate 40
Bedinvetmab 37
Sarolaner 31
Levetiracetam 29
Fluralaner 13.64% 12-Week Chew 29
Fluralaner Chew Tablets 19
Potassium Bromide 17
Afoxolaner 16
Moxidectin 16
Zonisamide 14
Milbemycin Oxime + Praziquantel 12
Carprofen 12
Gabapentin 11
Milbemycin Oxime + Spinosad 11
Selamectin 9
Anti-Il31 Mab Mcs Lot #1283563 9
Diazepam 9
Keppra 9

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Increased seizure frequency, 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 (305 here).

Similar death-coded share

Nearest other reactions by death-coded share (12.5% 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 Increased seizure frequency (#863 of 2,481 by report volume); death-coded 12.5%. PlainBreed reaction plate · death-coded report count stamp 38 · 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 →