Reaction profile

The FDA adverse-event record for lethargy (see also central nervous system depression in 'neurological')

92,802 FDA reports name lethargy (see also central nervous system depression in 'neurological'), a high-volume reaction in the CVM extract (VeDDRA 1018). Plate stamps and neighbourhood peers follow.

#2 of 2,481
by report volume (all reactions)
92,802
reports citing this reaction
9.5%
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. Lethargy (see also Central nervous system depression in 'Neurological') has 75,880 reports now versus 75,880 in that prior snapshot: 0 the same number of (0.0%).

Report change
+0
Death-coded reports
+0
Death-coded share
+0.0 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 Lethargy (see also Central nervous system depression in 'Neurological') changes

FDA AER · VeDDRA plate

Code 1018 VOL-MEGA

VOL-MEGA · DEATH-PAR · TOP-DECILE · CLEAR-GAP · SPECIES-DOG · DRUG-LEAD · DESK-WIDE · BOOK-FULL

  • VOL-MEGA 92,802 reports
  • DEATH-PAR 9.5%
  • TOP-DECILE #2/2481
  • CLEAR-GAP Emesis
  • SPECIES-DOG Dog · 65,146
  • DRUG-LEAD Milbemycin Oxime… · 20,659
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Emesis (±23,485 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 Lethargy

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

Vomiting · highest174348Lethargy (see also Ce… · thi…92802Emesis · near69317Diarrhoea · near64292Lack of efficacy (ect… · near59231Lack of efficacy - NOS · near54525Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Lethargy (see also Central nervous system depression in 'Neurological')

What the FDA AER plate says about Lethargy (see also Central nervous system depression in 'Neurological')

Signature read: 92,802 reports place Lethargy (see also Central nervous system depression in 'Neurological') in the upper third of FDA AER volume (#2 of 2,481). Report volume is upper-third scale: 92,802 named reports in the openFDA extract. 8,822 of 92,802 reports were death-coded (9.5% of named reports, not a population mortality rate). Nearest volume peer: Emesis (±23,485 reports). Lead species Dog (65,146). Lead co-reported drug Milbemycin Oxime + Spinosad (20,659).

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 65,146
Cat 9,864
Horse 417
Cattle 199
Human 50
Pig 47
Unknown 27
Rabbit 24
Goat 15
Sheep 14

Breeds Most Affected

Domestic Shorthair 5,956
Retriever - Labrador 5,869
Crossbred Canine/dog 4,285
Chihuahua 3,541
Terrier - Yorkshire 2,984
Retriever - Golden 2,729
Shih Tzu 2,587
Boxer (German Boxer) 2,285
Maltese 1,928
Shepherd Dog - German 1,860

Associated Drugs

Milbemycin Oxime + Spinosad 20,659
Spinosad 5,205
Afoxolaner 5,200
Moxidectin 3,738
Fluralaner Chew Tablets 3,354
Ivermectin + Pyrantel As Pamoate Salt 3,049
Carprofen 2,793
Trilostane 2,678
Imidacloprid + Moxidectin 2,397
Selamectin 2,293
Maropitant Citrate 2,283
Oclacitinib Maleate 2,121
Pyrantel Pamoate;Sarolaner 1,983
Milbemycin Oxime + Praziquantel 1,798
Cefovecin 1,757
Sarolaner 1,592
Nitenpyram 1,290
Prednisone 1,163
Fluralaner 13.64% 12-Week Chew 1,121
Fluralaner Spot-On Solution 1,058

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Lethargy (see also Central nervous system depression in 'Neurological'), 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 (92,802 here).

Similar death-coded share

Nearest other reactions by death-coded share (9.5% 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 Lethargy (see also Central nervous system depression in 'Neurological') (#2 of 2,481 by report volume); death-coded 9.5%. PlainBreed reaction plate · report volume stamp 92,802 · 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 →