Apoquel vs Zenrelia: what's the difference?
How Apoquel and Zenrelia compare: what each is for, how it works, side effects and cost, side by side.
Last updated: October 2026 · 3 sources · see sources
Side by side
| Apoquel | Zenrelia | |
|---|---|---|
| Generic name | Oclacitinib | Ilunocitinib |
| Brand names | Apoquel | Zenrelia |
| For | Dogs | Dogs |
| Prescription | Prescription | Prescription |
| Used for | Controls itching from allergic skin disease, including atopic dermatitis, in dogs at least 12 months old. Vets occasionally use it for other skin problems. [1] | Controls itching from allergic and atopic dermatitis in dogs at least 12 months old. [2] |
| How it works | It blocks JAK enzymes, which are part of the signal chain that drives itch and inflammation. Many dogs feel relief within a day or two. [1] | Like Apoquel, it is a JAK inhibitor that quiets the immune signals behind itch and inflammation. [2] |
| Common side effects | Vomiting, diarrhea or a lower appetite; tiredness; a higher chance of infections such as urinary, skin or respiratory infections; new skin lumps. [1] | Low appetite or energy, vomiting or diarrhea, ear infections and other infections. [2] |
| Use with care | Not for dogs with recent or current demodectic mange, serious infections, or cancer. Wear gloves or wash your hands after handling. Call your vet about fever, breathing trouble or any new lump. [1] | 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. [2] |
| Typical price | Apoquel pills, per fill: $30–$90 [3] | No reliable published price |
| Full guide | Apoquel guide | Zenrelia guide |
Key differences
On the basics they are alike: same kind of animal, same way to get them. The differences are in how they work and what else they cover, shown in the table above.
Which one is right for my pet?
That is a call for your vet. They weigh your pet's age, weight, other health problems, other medicines and what you can realistically give at home.
Switching from Apoquel to Zenrelia is common, but do it only with your vet's plan.
Common questions
What is the difference between Apoquel and Zenrelia?
Both are JAK-inhibitor pills for allergy itch in dogs at least 12 months old.
Is Apoquel better than Zenrelia?
Neither is better for every pet. Your vet chooses based on your pet's species, age, health history, other medicines and what you can manage at home.
Can my pet take Apoquel and Zenrelia together?
Only if your vet says so. Some medicines in the same family should not be combined, and others are often used together. Always check before adding or switching.
Do Apoquel and Zenrelia need a prescription?
Apoquel: Yes. It needs a prescription from a veterinarian. Zenrelia: Yes. It needs a prescription from a veterinarian.
How much do Apoquel and Zenrelia cost?
Apoquel: Apoquel pills, per fill $30–$90. Zenrelia: no reliable published price. Prices vary by pet size, pharmacy and clinic.
Related
This page is general information for planning, not veterinary advice. Talk to your vet about your own pet.