Dewormers Dogs & Cats

Ponazuril for dogs and cats

Treats coccidia and some other single-celled parasites in dogs and cats (off label; it is labeled for horses). [1]

Last reviewed: October 2026 · 2 sources · see sources

Quick answerPonazuril is a prescription medicine for dogs and cats. It disrupts how protozoal parasites grow and divide. The most common side effects: soft stool.

Key facts

Generic namePonazuril
Common brand namesMarquis
Used inDogs & Cats
TypeDewormers
Prescription?Prescription
Typical US priceNot listed (no reliable public source)

What it's used for

Treats coccidia and some other single-celled parasites in dogs and cats (off label; it is labeled for horses). [1]

How it works

It disrupts how protozoal parasites grow and divide. [1]

Side effects and cautions

Common side effects: Soft stool. Serious reactions are rare. [1]

Use with care: Use caution in dogs with dry eye and in pregnant or nursing pets. [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.

Ponazuril FAQ

What is Ponazuril used for in dogs and cats?

Treats coccidia and some other single-celled parasites in dogs and cats (off label; it is labeled for horses).

What are the side effects of Ponazuril?

Soft stool. Serious reactions are rare.

Does Ponazuril need a prescription?

Yes. It needs a prescription from a veterinarian.

How much Ponazuril 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 – Ponazuril (veterinary drug handout)
  2. FDA – Frequently asked questions about animal drugs