Reaction profile

The FDA adverse-event record for abnormal oestrus nos

56 FDA adverse-event reports reference abnormal oestrus nos (VeDDRA 1162). See the species, breeds, and drugs most associated with it below.

56
reports citing this reaction
7.1%
death-coded share
Dog
most-affected species
Milbemycin Oxime + Spinosad
most-associated drug
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56
Total Reports
4
Deaths
7.1%
Death Rate

Species Most Affected

Dog 36
Cattle 14
Horse 3
Sheep 1
Pig 1
Cat 1

Breeds Most Affected

Dog (unknown) 8
Holstein-Friesian also known as Holstein 5
Retriever - Labrador 4
Aberdeen Angus 3
Spaniel - Cocker American 2
Terrier - Yorkshire 2
Shepherd Dog - German 2
Crossbred Canine/dog 2
Doberman Pinscher 2
Cattle (unknown) 2

Associated Drugs

Milbemycin Oxime + Spinosad 11
Spinosad 7
Estradiol 5
Estriol Tablets 5
Monensin Sodium 3
Estradiol Benzoate; Trenbolone Acetate 3
Cyclosporine A 2
Vaccines (Unknown) 2
Estriol 2
Altrenogest Oily Solution 2
Melengestrol Acetate 2
Fluralaner Chew Tablets 2
Moxidectin 2
Progesterone 1
Pimobendan 1
Tacrolimus 1
Prednisolone; Trimeprazine Tartrate 1
Sometribove 1
Afoxolaner 1
Tiamulin Hydrogen Fumarate 1

Abnormal oestrus NOS Reaction Insights

56 reports name Abnormal oestrus NOS; 4 recorded a death outcome (7.1% of reported events, not a population-level mortality rate). VeDDRA code: 1162.

By species: Dog (36 reports), Cattle (14 reports), Horse (3 reports). By breed: Dog (unknown) (8), Holstein-Friesian also known as Holstein (5), Retriever - Labrador (4).

Most co-reported drugs: Milbemycin Oxime + Spinosad (11 reports), Spinosad (7 reports), Estradiol (5 reports), Estriol Tablets (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.