MGA® (liquid) and TM® — veterinary medication

Overview

Source: Animal Drugs @ FDA

Proprietary name

MGA® (liquid) and TM®

Active ingredient

Melengestrol Acetate Oxytetracycline

Application type

NADA

Sponsor

Phibro Animal Health Corp.

Applications on record

1

First published

November 12, 2024

Adverse event reports

Source: openFDA VeDDRA

763

Reports mentioning this ingredient

November 20, 1991 – November 24, 2025

54

Classified serious

per reporter assessment

203

Lack of expected efficacy

resistance signal

9

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 “MELENGESTROL ACETATE”. 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
INEFFECTIVE, ESTRUS SUPPRESSIO	513
Inappropriate preparation of medication	93
Lack of efficacy - NOS	65
No sign	36
Death	22
INEFFECTIVE, ESTRUS SYNCHRONIZ	18
Increased sexual interest	15
Death by euthanasia	11
Accidental exposure	9
Residues in meat/offal	8
Closure, Abnormal	7
Infertility NOS	6
Behavioural disorder NOS	6
Seal, Abnormal	5
Lameness	5
Underdose	5
Underfilling, Container	5
Mammary gland disorder NOS	4
Rectal prolapse	4
Containers, Leaking	4

Species affected

Source: openFDA VeDDRA

Cattle 731 Sheep 2 Other Deer 1 Human 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