Reaction profile

The FDA adverse-event record for lack of efficacy (tick)

6,102 FDA reports name lack of efficacy (tick), a high-volume reaction in the CVM extract (VeDDRA 2658). Plate stamps and neighbourhood peers follow.

#84 of 2,481
by report volume (all reactions)
6,102
reports citing this reaction
1.2%
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. Lack of efficacy (tick) has 6,102 reports now versus 6,102 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 Lack of efficacy (tick) changes

FDA AER · VeDDRA plate

Code 2658 VOL-HIGH

VOL-HIGH · DEATH-LOW · TOP-DECILE · PHOTO-FINISH · SPECIES-DOG · DRUG-LEAD · DESK-WIDE · BOOK-FULL

  • VOL-HIGH 6,102 reports
  • DEATH-LOW 1.2%
  • TOP-DECILE #84/2481
  • PHOTO-FINISH Hyperglycaemia
  • SPECIES-DOG Dog · 5,999
  • DRUG-LEAD Afoxolaner · 2,200
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Hyperglycaemia (±72 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 Lack of efficacy

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

Vomiting · highest174348Weight gain · near6282Pale mucous membrane · near6258Not drinking · near6221Hyperglycaemia · near6174Lack of efficacy (tic… · thi…6102Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Lack of efficacy (tick)

Lack of efficacy (tick): low death-coded share in the FDA AER plate

Signature read: 6,102 reports place Lack of efficacy (tick) in the upper third of FDA AER volume (#84 of 2,481). Report volume is upper-third scale: 6,102 named reports in the openFDA extract. Death-coded share is lower-third: 71 of 6,102 reports (1.2% of named reports). Nearest volume peer: Hyperglycaemia (±72 reports). Lead species Dog (5,999). Lead co-reported drug Afoxolaner (2,200).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Afoxolaner 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 5,999
Cat 88
Cattle 11
Marsupial 2
Sheep 1
Deer 1

Breeds Most Affected

Crossbred Canine/dog 716
Retriever - Labrador 715
Dog (unknown) 449
Retriever - Golden 383
Shepherd Dog - German 296
Shih Tzu 248
Terrier - Yorkshire 175
Pit Bull 119
Shepherd Dog - Australian 118
Beagle 116

Associated Drugs

Afoxolaner 2,200
Fluralaner Chew Tablets 1,427
Sarolaner 850
Afoxolaner 28.3 Mg Chewable Tablets 468
Recombitek Lyme - 2126.R0 446
Afoxolaner 68 Mg Chewable Tablets 288
Afoxolaner 11.3 Mg Chewable Tablets 244
Recombinant E. Coli Bl21;Recombinant E. Coli Ecl19 214
Afoxolaner 136 Mg Chewable Tablets 202
Fluralaner 13.64% 12-Week Chew 138
Ivermectin + Pyrantel As Pamoate Salt 135
Canine B Burgdorferi *2 Alu Kb 101
Lotilaner 91
Fluralaner Spot-On Solution 74
Milbemycin Oxime + Spinosad 62
Milbemycin Oxime + Praziquantel 53
Selamectin 45
Fluralaner 13.64% Chew Tablets 25
Fipronil + S-Methoprene 23
Fipronil + Pyriproxyfen + S-Methoprene 21

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Lack of efficacy (tick), 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 (6,102 here).

Similar death-coded share

Nearest other reactions by death-coded share (1.2% 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 Lack of efficacy (tick) (#84 of 2,481 by report volume); death-coded 1.2%. PlainBreed reaction plate · report volume stamp 6,102 · 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 →