Reaction profile

The FDA adverse-event record for application site hair loss

8,127 FDA reports name application site hair loss, a high-volume reaction in the CVM extract (VeDDRA 3). Plate stamps and neighbourhood peers follow.

#57 of 2,481
by report volume (all reactions)
8,127
reports citing this reaction
0.6%
death-coded share
Cat
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. Application site hair loss has 8,127 reports now versus 7,992 in that prior snapshot: 135 more (1.7%).

Report change
+135
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 Application site hair loss changes

FDA AER · VeDDRA plate

Code 3 VOL-HIGH

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

  • VOL-HIGH 8,127 reports
  • DEATH-RARE 0.6%
  • TOP-DECILE #57/2481
  • PHOTO-FINISH Color, Abnormal
  • SPECIES-CAT Cat · 7,811
  • DRUG-LEAD Selamectin;Sarola… · 2,295
  • DESK-WIDE 20 breeds
  • BOOK-FULL 8/8 fields

Nearest volume peer: Color, Abnormal (±40 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 Application site hair loss

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

Vomiting · highest174348Lack of efficacy (fle… · near8320Lack of efficacy (end… · near8280Application site hair… · thi…8127Color, Abnormal · near8087Tremor · near8033Urinary tract neoplas… · low…10
FDA AER report volume · neighbourhood around Application site hair loss

Application site hair loss: low death-coded share in the FDA AER plate

Signature read: 8,127 reports place Application site hair loss in the upper third of FDA AER volume (#57 of 2,481). Report volume is upper-third scale: 8,127 named reports in the openFDA extract. Death-coded share is lower-third: 49 of 8,127 reports (0.6% of named reports). Nearest volume peer: Color, Abnormal (±40 reports). Lead species Cat (7,811). Lead co-reported drug Selamectin;Sarolaner (2,295).

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

Cat 7,811
Dog 285
Cattle 22
Horse 3
Rabbit 2
Human 2
Bobcat 1
Lynx 1

Breeds Most Affected

Domestic Shorthair 5,339
Domestic Longhair 522
Domestic Mediumhair 468
Cat (other) 393
Cat (unknown) 234
Siamese 165
Maine Coon 137
Bengal 86
Russian 60
Crossbred Feline/cat 58

Associated Drugs

Selamectin;Sarolaner 2,295
Selamectin 2,262
Fluralaner Spot-On Solution 1,872
Fluralaner/Moxidectin Spot-On 642
Eprinomectin + Esafoxolaner + Praziquantel 269
Buprenorphine 199
Emodepside + Praziquantel 197
Imidacloprid + Moxidectin 180
Cefovecin 59
Isoflurane 52
Ivermectin + Pyrantel As Pamoate Salt 51
Robenacoxib 50
Maropitant Citrate 43
Propofol 39
Methylprednisolone Acetate 35
Dexmedetomidine 34
Spinetoram 32
Fipronil 10%/S Methoprene 9% Spot On 32
Cefovecin Sodium 32
Eprinomectin + Praziquantel 30

Nationwide reactions with similar profiles

Two openFDA-derived peer sets for Application site hair loss, both floored at ≥50 reports so the neighborhoods stay in the advertised mass (the volume chart above is the unfloored photo-finish strip).

Similar death-coded share

Nearest other reactions by death-coded share (0.6% 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 Application site hair loss (#57 of 2,481 by report volume); death-coded 0.6%. PlainBreed reaction plate · report volume stamp 8,127 · 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 →