Allergy & itch Dogs

Zenrelia for dogs

Controls itching from allergic and atopic dermatitis in dogs at least 12 months old. [1]

Last reviewed: October 2026 · 2 sources · see sources

Quick answerZenrelia (ilunocitinib) is a prescription medicine for dogs. Like Apoquel, it is a JAK inhibitor that quiets the immune signals behind itch and inflammation. The most common side effects: low appetite or energy, vomiting or diarrhea, ear infections and other infections.

Key facts

Generic nameIlunocitinib
Common brand namesZenrelia
Used inDogs
TypeAllergy & itch
Prescription?Prescription
Typical US priceNot listed (no reliable public source)

What it's used for

Controls itching from allergic and atopic dermatitis in dogs at least 12 months old. [1]

How it works

Like Apoquel, it is a JAK inhibitor that quiets the immune signals behind itch and inflammation. [1]

Side effects and cautions

Common side effects: Low appetite or energy, vomiting or diarrhea, ear infections and other infections. [1]

Use with care: Dogs must be up to date on vaccines, and it should not be started within 28 days of a vaccine. Not for pregnant or nursing dogs. Ask your vet how it fits with your dog's vaccine schedule. [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.

Zenrelia FAQ

What is Zenrelia used for in dogs?

Controls itching from allergic and atopic dermatitis in dogs at least 12 months old.

What are the side effects of Zenrelia?

Low appetite or energy, vomiting or diarrhea, ear infections and other infections.

Does Zenrelia need a prescription?

Yes. It needs a prescription from a veterinarian.

How much Zenrelia 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.

Related medications

Related cost guides

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 – Ilunocitinib (veterinary drug handout)
  2. FDA – Frequently asked questions about animal drugs