Reaction profile

The FDA adverse-event record for reduced testicle size

15 FDA adverse-event reports reference reduced testicle size (VeDDRA 2033). See the species, breeds, and drugs most associated with it below.

15
reports citing this reaction
40.0%
death-coded share
Dog
most-affected species
Trilostane
most-associated drug
Verify with FDA CVM →
15
Total Reports
6
Deaths
40.0%
Death Rate

Species Most Affected

Dog 14
Horse 1

Breeds Most Affected

Retriever - Labrador 3
Spaniel - Springer English 1
Shepherd Dog - Belgian Malinois 1
Retriever - Golden 1
Terrier - Boston 1
Pit Bull 1
Dog (unknown) 1
Shih Tzu 1
American Pit Bull Terrier 1
Quarter Horse 1

Associated Drugs

Trilostane 4
Milbemycin Oxime + Spinosad 3
Famotidine 2
Fluralaner Chew Tablets 2
Cefovecin 1
Imidacloprid + Moxidectin 1
Imidacloprid + Permethrin + Pyriproxyfen 1
Flumethrin-Imidacloprid 1
Doxycycline 1
Steriod 1
Isotonic Fluids 1
Spinosad 1
Rabies Vaccine 1
Da2Ppv+L*4 (Orig S-P Us) Lv+Kb 1
Rabies In Hhh Adj Pfizer Kv 1
Toceranib Phosphate 1
Gonadotropin Releasing Factor (Gnrf) - Diphtheria Toxoid Conjugate 1
Capromorelin Tartrate 1
Canine Distemper-Adenovirus Type 2-Parainfluenza-Parvovirus Vaccine, Mlv, Leptospira Canicola-Grippotyphosa-Icterohaemorrhagiae-Pomona Bacterial Extract 1
Amoxicillin + Clavulanic Acid 1

Reduced testicle size Reaction Insights

15 reports name Reduced testicle size; 6 recorded a death outcome (40.0% of reported events, not a population-level mortality rate). VeDDRA code: 2033.

By species: Dog (14 reports), Horse (1 reports). By breed: Retriever - Labrador (3), Spaniel - Springer English (1), Shepherd Dog - Belgian Malinois (1).

Most co-reported drugs: Trilostane (4 reports), Milbemycin Oxime + Spinosad (3 reports), Famotidine (2 reports), Fluralaner Chew Tablets (2 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.