Reaction profile
The FDA adverse-event record for lack of efficacy (virus) - nos
227 FDA adverse-event reports reference lack of efficacy (virus) - nos (VeDDRA 2660). Plate codes and volume neighbourhood below; species, breeds, and drugs follow.
- #977 of 2,481
- by report volume (all reactions)
- 227
- reports citing this reaction
- 23.8%
- 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 (virus) - NOS has 130 reports now versus 126 in that prior snapshot: 4 more (3.2%).
- Report change
- +4
- Death-coded reports
- +4
- Death-coded share
- +2.1 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 (virus) - NOS changesFDA AER · VeDDRA plate
Code 2660 VOL-LOW
VOL-LOW · DEATH-HOT · MID-PACK · PHOTO-FINISH · SPECIES-DOG · DRUG-LEAD · DESK-WIDE · BOOK-FULL
- VOL-LOW 227 reports
- DEATH-HOT 23.8%
- MID-PACK #977/2481
- PHOTO-FINISH Application site self…
- SPECIES-DOG Dog · 70
- DRUG-LEAD Milbemycin Oxime… · 44
- DESK-WIDE 20 breeds
- BOOK-FULL 8/8 fields
Nearest volume peer: Application site self trauma (±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 Lack of efficacy - NOS
Highest and lowest poles plus nearest volume peers, not a full 2,500-reaction corpus board reprint.
What the FDA AER plate says about Lack of efficacy (virus) - NOS
Signature read: 54 death-coded reports is a heavy tail count for Lack of efficacy (virus) - NOS in the CVM extract. Report volume sits in the middle third of the reaction corpus. 54 of 227 reports were death-coded (23.8% of named reports, not a population mortality rate). Nearest volume peer: Application site self trauma (±0 reports). Lead species Dog (70). Lead co-reported drug Milbemycin Oxime + Praziquantel (44).
Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Milbemycin Oxime + Praziquantel 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
Nationwide reactions with similar profiles
Two openFDA-derived peer sets for Lack of efficacy (virus) - NOS, 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 (227 here).
Similar death-coded share
Nearest other reactions by death-coded share (23.8% here), distinct from the volume row.
What to do with this reaction
- Compare Lack of efficacy - NOS'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
Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →