Reaction profile

The FDA adverse-event record for ineffective, estrus suppressio

139 FDA adverse-event reports reference ineffective, estrus suppressio (VeDDRA 99103). See the species, breeds, and drugs most associated with it below.

139
reports citing this reaction
5.8%
death-coded share
Cattle
most-affected species
Melengestrol Acetate
most-associated drug
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139
Total Reports
8
Deaths
5.8%
Death Rate

Species Most Affected

Cattle 114
Horse 24
Pig 1

Breeds Most Affected

Mixed (Cattle) 45
Cattle (other) 28
Cattle (unknown) 23
Crossbred Bovine/Cattle 12
Quarter Horse 6
Horse (unknown) 5
Aberdeen Angus 3
Paint 3
Thoroughbred 3
Holstein-Friesian also known as Holstein 2

Associated Drugs

Melengestrol Acetate 110
Altrenogest Oily Solution 17
Altrenogest 8
Monensin Sodium 5
Monensin 3
Progesterone 2
Tylosin Phosphate 2
Melengestrol Acetate, Monensin Sodium, Tylosin Phosphate 1
Progesterone, Estradiol Benzoate, Tylosin Tartrate 1
Unspecified 1
Tilmicosin Phosphate 1
Ractopamine Hydrochloride 1
Dinoprost Tromethamine 1
Lasalocid Sodium 1
Trenbolone Acetate + Estradiol 1
Gonadorelin Diacetate Tetrahydrate 1
Testosterone Propionate;Estradiol Benzoate 1
Progesterone;Estradiol Benzoate 1

INEFFECTIVE, ESTRUS SUPPRESSIO Reaction Insights

139 reports name INEFFECTIVE, ESTRUS SUPPRESSIO; 8 recorded a death outcome (5.8% of reported events, not a population-level mortality rate). VeDDRA code: 99103.

By species: Cattle (114 reports), Horse (24 reports), Pig (1 reports). By breed: Mixed (Cattle) (45), Cattle (other) (28), Cattle (unknown) (23).

Most co-reported drugs: Melengestrol Acetate (110 reports), Altrenogest Oily Solution (17 reports), Altrenogest (8 reports), Monensin Sodium (5 reports).

Read these counts as reporting volume, not risk: per our methodology, co-reporting reflects temporal association captured in voluntary submissions, not proof that a drug caused this reaction. A widely-prescribed drug will rack up more raw co-reports at an identical true rate than a rarely-used one, so compare within similar-exposure products.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.