ComfortisTM — veterinary medication

Overview

Source: Animal Drugs @ FDA

Proprietary name

ComfortisTM

Active ingredient

Spinosad

Application type

NADA

Sponsor

Elanco US Inc.

Applications on record

1

First published

September 24, 2026

Adverse event reports

Source: openFDA VeDDRA

206,573

Reports mentioning this ingredient

May 1, 2007 – March 23, 2026

19,481

Classified serious

per reporter assessment

39,844

Lack of expected efficacy

resistance signal

3,127

Human operator exposure

needle-stick or splash

Not a risk measure. Veterinary adverse event reports are influenced by how many animals are treated, reporting practice and product age. Reports do not establish that the product caused the event, and a single report can cover an entire herd or flock. Attribution here is by active ingredient because the source dataset redacts brand names.

Attributed by active ingredient “SPINOSAD”. Green Book ingredient names and VeDDRA ingredient names do not always agree exactly, so attribution is approximate and labelled as such.

Reported reactions

Source: openFDA VeDDRA

Clinical signs coded in the VICH VeDDRA four-level hierarchy, most frequent first.

Reaction terms reported for this ingredient, by report count.
Reaction (VeDDRA term)	Reports	Relative frequency
Emesis	59,709
Vomiting	48,649
Lethargy (see also Central nervous system depression in 'Neurological')	23,021
Lack of efficacy (ectoparasite) - flea	20,594
UNPALATABLE	16,855
Lack of efficacy - NOS	14,092
Diarrhoea	8,558
Seizure NOS	5,268
INEFFECTIVE, HEARTWORM LARVAE	5,166
Behavioural disorder NOS	4,946
Lack of efficacy (endoparasite) - heartworm	4,397
Anorexia	4,351
Ataxia	3,842
Pruritus	3,782
Depression	3,701
Product problem	3,467
Shaking	3,435
Emesis (multiple)	3,357
Itching	3,283
Not eating	3,148

Species affected

Source: openFDA VeDDRA

Dog 180,051 Cat 11,858 Human 441 Other 13 Other Canids 13 Wolf 2 Fish 1 Macaw 1 Crustacea 1 Cattle 1

Regulatory context

New Animal Drug Application (NADA). A pioneer approval evaluated for target animal safety, therapeutic effectiveness, manufacturing controls and — for food-producing species — human food safety including residue depletion.

Extra-label use in food-producing animals is governed by the Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA) and 21 CFR Part 530. It requires a valid veterinarian-client-patient relationship and is prohibited outright for certain drug classes. Withdrawal times are determined by FARAD, not by this index.

Sources for this page

Animal Drugs @ FDA	FDA CVM	Applications, sponsor, status, withdrawal
Animal & Veterinary Events	FDA CVM	VeDDRA adverse event aggregates by active ingredient