Reaction profile
The FDA adverse-event record for lack of efficacy (endoparasite) - cooperia
36 FDA reports name lack of efficacy (endoparasite) - cooperia, a lower-volume reaction in the CVM extract (VeDDRA 2795). Plate stamps and neighbourhood peers follow.
- #1911 of 2,481
- by report volume (all reactions)
- 36
- reports citing this reaction
- 5.6%
- death-coded share
- Cattle
- 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 (endoparasite) - Cooperia has 36 reports now versus 36 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 (endoparasite) - Cooperia changesFDA AER · VeDDRA plate
Code 2795 VOL-TRACE
VOL-TRACE · DEATH-PAR · LOWER-Q · PHOTO-FINISH · SPECIES-CATTLE · DRUG-LEAD · DESK-WIDE · BOOK-FULL
- VOL-TRACE 36 reports
- DEATH-PAR 5.6%
- LOWER-Q #1911/2481
- PHOTO-FINISH Abnormal birth weight
- SPECIES-CATTLE Cattle · 24
- DRUG-LEAD Eprinomectin · 20
- DESK-WIDE 15 breeds
- BOOK-FULL 8/8 fields
Nearest volume peer: Abnormal birth weight (±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.
Lower-volume neighbourhood around Lack of efficacy - Cooperia
Lower-third volume poles plus nearest peers, not a full reaction corpus board reprint.
Lack of efficacy (endoparasite) - Cooperia: low death-coded share in the FDA AER plate
Signature read: 2 death-coded reports is a thin tail count for Lack of efficacy (endoparasite) - Cooperia in the CVM extract. Report volume is lower-third scale: 36 named reports in the openFDA extract. Death-coded share is lower-third: 2 of 36 reports (5.6% of named reports). Nearest volume peer: Abnormal birth weight (±0 reports). Lead species Cattle (24). Lead co-reported drug Eprinomectin (20).
Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Eprinomectin 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
Breeds Most Affected
Associated Drugs
What to do with this reaction
- 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
Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →