Reaction profile

The FDA adverse-event record for encephalitis

146 FDA adverse-event reports reference encephalitis (VeDDRA 633). Plate codes and volume neighbourhood below; species, breeds, and drugs follow.

#1207 of 2,481
by report volume (all reactions)
146
reports citing this reaction
52.1%
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. Encephalitis has 146 reports now versus 145 in that prior snapshot: 1 more (0.7%).

Report change
+1
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 Encephalitis changes

FDA AER · VeDDRA plate

Code 633 VOL-LOW

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

  • VOL-LOW 146 reports
  • DEATH-HOT 52.1%
  • MID-PACK #1207/2481
  • PHOTO-FINISH Abnormal vision (see…
  • SPECIES-DOG Dog · 114
  • DRUG-LEAD Milbemycin Oxime… · 18
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Abnormal vision (see also impaired vision) (±0 reports)

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

Report-volume neighbourhood around Encephalitis

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

Vomiting · highest174348Abnormal vision (see… · near146Encephalitis · this reaction146Gastric bloat · near146Generalised skin reac… · near146Hyphaemia · near146Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Encephalitis

Encephalitis: high death-coded share in the FDA AER plate

Signature read: Encephalitis's 52.1% death-coded share is among the highest in the openFDA reaction corpus. Report volume sits in the middle third of the reaction corpus. Death-coded share is upper-third: 76 of 146 reports (52.1% of named reports). Nearest volume peer: Abnormal vision (see also impaired vision) (±0 reports). Lead species Dog (114). Lead co-reported drug Milbemycin Oxime + Spinosad (18).

Read these counts as reporting volume, not risk: per our methodology, A high death-coded share in FDA filings does not prove causation; co-reporting is voluntary temporal association only. Browse the full reactions index or the about page for how PlainBreed frames FDA CVM extracts.

Species Most Affected

Dog 114
Cat 17
Cattle 8
Rabbit 1
Human 1
Other Birds 1
Ferret 1
Goat 1
Horse 1
Pig 1

Breeds Most Affected

Retriever - Golden 13
Domestic Shorthair 12
Terrier - Yorkshire 9
Retriever - Labrador 7
Crossbred Canine/dog 6
Chihuahua 5
Maltese 5
Shih Tzu 4
Terrier (unspecified) 4
Unknown 3

Associated Drugs

Milbemycin Oxime + Spinosad 18
Moxidectin 12
Fluralaner Chew Tablets 11
Maropitant Citrate 10
Afoxolaner 9
Spinosad 8
Carprofen 8
Pyrantel Pamoate;Sarolaner 8
Enrofloxacin 7
Meloxicam 7
Sarolaner 7
Prednisone 6
Gabapentin 6
Robenacoxib 6
Bedinvetmab 6
Cefovecin 5
Doxycycline 5
Clindamycin 5
Oclacitinib Maleate 5
Fluralaner 13.64% 12-Week Chew 5

Nationwide reactions with similar profiles

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

Similar death-coded share

Nearest other reactions by death-coded share (52.1% 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 Encephalitis (#1207 of 2,481 by report volume); death-coded 52.1%. PlainBreed reaction plate · death-coded share stamp 52.1% · 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 →