Synanthic® Bovine Dewormer Paste, 18.5% — veterinary medication

Overview

Source: Animal Drugs @ FDA

Proprietary name

Synanthic® Bovine Dewormer Paste, 18.5%

Active ingredient

Oxfendazole

Application type

NADA

Sponsor

Zoetis Inc.

Applications on record

1

First published

June 18, 2018

Adverse event reports

Source: openFDA VeDDRA

296

Reports mentioning this ingredient

October 26, 1987 – February 19, 2026

145

Classified serious

per reporter assessment

151

Lack of expected efficacy

resistance signal

1

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 “OXFENDAZOLE”. 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
Death	107
Lack of efficacy - NOS	43
Death by euthanasia	12
Lack of efficacy (bacteria) - NOS	12
CULTURE/TITER DATA ABNORMAL	11
Lack of efficacy (bacteria NOS)	11
INEFFECTIVE, STRONGYLES	10
Caps, Abnormal	10
Respiratory signs	10
Necropsy performed	10
INEFFECTIVE, WORMS NOS	9
Vials, Leaking	9
Product Defect, General	9
Other abnormal test result NOS	8
NT - Abnormal necropsy finding NOS	8
Lack of efficacy (endoparasite) - tapeworm	7
Seal, Abnormal	6
Anaphylaxis	6
Lack of efficacy (protozoa) - Coccidia	6
Containers, Leaking	6

Species affected

Source: openFDA VeDDRA

Cattle 215 Dog 19 Sheep 6 Horse 4 Human 4 Goat 4 Other 1 Buffalo 1 Alpaca 1 Bison 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