Reaction profile

The FDA adverse-event record for ineffective, heartworm microfi

118 FDA adverse-event reports reference ineffective, heartworm microfi (VeDDRA 99117). Plate codes and volume neighbourhood below; species, breeds, and drugs follow.

#1311 of 2,481
by report volume (all reactions)
118
reports citing this reaction
0.8%
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. INEFFECTIVE, HEARTWORM MICROFI has 118 reports now versus 118 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, HEARTWORM MICROFI changes

FDA AER · VeDDRA plate

Code 99117 VOL-LOW

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

  • VOL-LOW 118 reports
  • DEATH-RARE 0.8%
  • MID-PACK #1311/2481
  • PHOTO-FINISH Prostration
  • SPECIES-DOG Dog · 118
  • DRUG-LEAD Imidacloprid + Mo… · 26
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Prostration (±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, HEARTWORM MICROFI

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

Vomiting · highest174348Dry heaving · near119INEFFECTIVE, HEARTWOR… · thi…118Prostration · near118Scleritis · near118Cold feeling of extre… · near117Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around INEFFECTIVE, HEARTWORM MICROFI

INEFFECTIVE, HEARTWORM MICROFI: low death-coded share in the FDA AER plate

Signature read: INEFFECTIVE, HEARTWORM MICROFI's 0.8% 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 118 reports (0.8% of named reports). Nearest volume peer: Prostration (±0 reports). Lead species Dog (118). Lead co-reported drug Imidacloprid + Moxidectin (26).

Read these counts as reporting volume, not risk: per our methodology, Lead co-reported drug Imidacloprid + Moxidectin 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 118

Breeds Most Affected

Retriever - Labrador 21
Crossbred Canine/dog 18
Dog (unknown) 9
Shepherd Dog - German 8
Beagle 6
Retriever - Golden 5
Hound (unspecified) 4
Collie - Border 4
Terrier (unspecified) 3
Catahoula Leopard Dog 3

Associated Drugs

Imidacloprid + Moxidectin 26
Melarsomine Dihydrochloride 24
Ivermectin 22
Doxycycline 19
Melarsomine 12
Ivermectin + Pyrantel 12
Melarsomine Dihydrochloride Injection 11
Moxidectin 11
Ivermectin + Pyrantel As Pamoate Salt 11
Selamectin 7
Milbemycin Oxime 6
Prednisone 6
Milbemycin 5
Milbemycin Oxime + Spinosad 5
Ivermectin 1% Injection 3
Lufenuron + Milbemycin Oxime 3
Milbemycin Oxime + Praziquantel 3
Imidacloprid, Moxidectin 3
Ivermectin, Pyrantel 2
Ivermectin & Pyrantel 2

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for INEFFECTIVE, HEARTWORM MICROFI, 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 (118 here).

Similar death-coded share

Nearest other reactions by death-coded share (0.8% 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 INEFFECTIVE, HEARTWORM MICROFI (#1311 of 2,481 by report volume); death-coded 0.8%. PlainBreed reaction plate · death-coded share stamp 0.8% · 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 →