Thyroid & hormones Dogs

Vetoryl for dogs

Treats Cushing's disease (hyperadrenocorticism) in dogs. [1]

Last reviewed: October 2026 · 2 sources · see sources

Quick answerVetoryl (trilostane) is a prescription medicine for dogs. It blocks an enzyme the adrenal glands need to make cortisol. The most common side effects: tiredness, vomiting, diarrhea and low appetite, mostly early on.

Key facts

Generic nameTrilostane
Common brand namesVetoryl
Used inDogs
TypeThyroid & hormones
Prescription?Prescription
Typical US priceNot listed (no reliable public source)

What it's used for

Treats Cushing's disease (hyperadrenocorticism) in dogs. [1]

How it works

It blocks an enzyme the adrenal glands need to make cortisol. [1]

Side effects and cautions

Common side effects: Tiredness, vomiting, diarrhea and low appetite, mostly early on. [1]

Use with care: Too much can cause an Addison's-like crisis: weakness, collapse, vomiting. Regular rechecks with bloodwork are part of treatment. Not for pregnant dogs. [1]

Call your vet right away if your pet has trouble breathing, facial swelling, hives, collapse, or any side effect that is severe or getting worse.

About dosingDosing is your vet's call. We don't list doses because the right amount depends on your pet's weight, age, health and other medicines. Don't change a dose or stop a medicine without asking your vet, and never give a pet medicine meant for people unless your vet tells you to [2].

What it costs

We don't list a price for this one because we couldn't find a reliable public source. Ask your vet or pharmacy for a quote; prices depend on your pet's size, the dose and where you fill it.

Vetoryl FAQ

What is Vetoryl used for in dogs?

Treats Cushing's disease (hyperadrenocorticism) in dogs.

What are the side effects of Vetoryl?

Tiredness, vomiting, diarrhea and low appetite, mostly early on.

Does Vetoryl need a prescription?

Yes. It needs a prescription from a veterinarian.

How much Vetoryl should I give my pet?

Only your veterinarian can tell you. The right dose depends on your pet's weight, health and other medicines, so we don't list doses. Never give a pet a medicine prescribed for a person or another animal without asking your vet.

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This page is general information for pet owners, not veterinary advice. Talk to your vet about your own pet.

Sources (2) — tap to show
  1. VCA Animal Hospitals – Trilostane (veterinary drug handout)
  2. FDA – Frequently asked questions about animal drugs