Reaction profile

The FDA adverse-event record for ineffective, lice biting

Name: INEFFECTIVE, LICE BITING - FDA Animal Adverse Reaction
Creator: PlainBreed
License: https://open.fda.gov/license/

290 FDA adverse-event reports reference ineffective, lice biting (VeDDRA 99123). Plate codes and volume neighbourhood below; species, breeds, and drugs follow.

#880 of 2,481
by report volume (all reactions): 290
reports citing this reaction: 0.3%
death-coded share: Cattle
most-affected species

Compiled by PlainBreed

Verify with FDA CVM →

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. INEFFECTIVE, LICE BITING has 290 reports now versus 290 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 INEFFECTIVE, LICE BITING changes

FDA AER · VeDDRA plate

Code 99123 VOL-LOW

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

VOL-LOW 290 reports
DEATH-RARE 0.3%
MID-PACK #880/2481
PHOTO-FINISH INEFFECTIVE, ASCARIDS
SPECIES-CATTLE Cattle · 286
DRUG-LEAD Doramectin · 94
DESK-WIDE 18 breeds
BOOK-FULL 8/8 fields

Nearest volume peer: INEFFECTIVE, ASCARIDS (±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 INEFFECTIVE, LICE BITING

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

FDA AER report volume · neighbourhood around INEFFECTIVE, LICE BITING

INEFFECTIVE, LICE BITING: low death-coded share in the FDA AER plate

Signature read: INEFFECTIVE, LICE BITING's 0.3% death-coded share is among the lowest in the openFDA reaction corpus. Report volume sits in the middle third of the reaction corpus. Death-coded share is lower-third: 1 of 290 reports (0.3% of named reports). Nearest volume peer: INEFFECTIVE, ASCARIDS (±0 reports). Lead species Cattle (286). Lead co-reported drug Doramectin (94).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Doramectin 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

Cattle 286

Dog 3

Cat 1

Breeds Most Affected

Crossbred Bovine/Cattle 57

Cattle (unknown) 57

Aberdeen Angus 57

Cattle (other) 56

Mixed (Cattle) 34

Charolais 6

Simmental 4

Unknown 4

Holstein-Friesian also known as Holstein 3

Red Angus 2

Associated Drugs

Doramectin 94

Ivermectin 0.5% Pour-On Topical Solution 61

Ivermectin 58

Portech App Gun 65 Ml Ivomec/Eprinex 41

Eprinomectin 18

Eprinomectin 5 Mg/Ml Pour-On Solution 12

Moxidectin 9

Ivermectin 0.5% Pour-On 8

Eprinomectin 0.5% Pour-On 8

Clorsulon, Ivermectin 7

Device - Applicator Gun 5

Ivermectin(1%)/Clorsulon(10%) Injection 5

Merial La Polypropylene Syringe 4

Doramectin; Phenol 4

Breaze App Gun 80 Ml Ivomec/Eprinex 3

Eprinomectin Topical 2

Ivermectin 1% Injection 2

Selamectin 2

Fluralaner 13.64% 12-Week Chew 2

Ivermectin Pour-On Cattle 1

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for INEFFECTIVE, LICE BITING, 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 (290 here).

INEFFECTIVE, ASCARIDS 290 Application site dermatitis 289 Difficulty going up/down stairs 289 Haemoconcentration 289

Similar death-coded share

Nearest other reactions by death-coded share (0.3% here), distinct from the volume row.

Lack of efficacy (ectoparasite) - ear mite 0.4% Lack of efficacy (protozoa) - Giardia 0.3% Product defect, product difficult to use/handle (see also 'Drug device difficult to use/handle') 0.4% Lack of efficacy (ectoparasite) - NOS 0.4%

What to do with this reaction

Compare INEFFECTIVE, LICE BITING's report profile against similar reactions nationwide. See similar reactions
Read how death-coded share differs from a mortality rate before drawing conclusions. Understanding adverse events
Browse the full reaction directory to compare report counts across reaction types. All reactions

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 INEFFECTIVE, LICE BITING (#880 of 2,481 by report volume); death-coded 0.3%. PlainBreed reaction plate · death-coded share stamp 0.3% · 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 →