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Medication Guide • Reviewed by Dr. Tiffany Delacruz, DVM

Apoquel for Dogs

Apoquel is a prescription anti-itch medication that controls allergic itch (pruritus) and inflammation in dogs. It works fast — many dogs feel relief within 4 hours.

Generic: oclacitinib Class: Janus kinase (JAK) inhibitor Prescription required FDA-approved for dogs
Important: This page is an educational reference. Never start, stop, or change your pet's medication without veterinary guidance. Specific dosing depends on your pet's weight, condition, and other medications. To get a personalized prescription or refill, talk to a licensed RexVet veterinarian.

What Apoquel is used for in dogs

  • Itching caused by allergic dermatitis
  • Atopic dermatitis (environmental allergies)
  • Acute and chronic itch from skin allergies

How it works

Apoquel blocks JAK enzymes inside immune cells, which interrupts the itch signal pathway. Unlike steroids, it targets the itch directly without broadly suppressing the immune system.

Available formulations

3.6 mg tablet

5.4 mg tablet

16 mg tablet

chewable tablet

Side effects to know

Common side effects

  • Mild vomiting
  • Diarrhea
  • Lethargy
  • Decreased appetite

These usually resolve on their own. If they persist past the first few doses, ask your vet.

Call your vet immediately if you see

  • Signs of infection (fever, persistent cough, lethargy)
  • New skin lumps or growths
  • Bloody diarrhea
  • Severe vomiting

Drug interactions

  • Other immunosuppressive drugs (e.g. cyclosporine)
  • Corticosteroids (combined use generally avoided)
  • Live vaccines (consult your vet)

When not to use

  • Dogs under 12 months of age
  • Dogs with serious infections
  • Dogs with a history of certain cancers
  • Pregnant or breeding dogs

Monitoring during treatment

Your vet may check bloodwork periodically, especially during the first months of use. Report new lumps, ongoing infections, or unusual behavior.

Need a Apoquel refill?

RexVet is the first 501(c)(3) non-profit online vet service in the U.S. Talk to a licensed veterinarian by video, get your dogs's Apoquel prescription, and have it shipped through RexVetRx — all for $64.99 per visit.

Book a vet visit — $64.99

Apoquel for Dogs

Frequently asked questions

How quickly does Apoquel work in dogs?

Most dogs show noticeable reduction in itching within 4 hours of the first dose, with full effect typically seen within 24 hours. It does not cure the underlying allergy — itch returns when the medication stops.

Can my dog take Apoquel long-term?

Yes — Apoquel is approved for long-term use under veterinary supervision. Your vet will recommend periodic bloodwork to monitor for infections and other long-term effects.

Is Apoquel safer than steroids for my dog?

Apoquel targets the itch pathway specifically without the broader immune suppression of long-term steroid use, which is why many vets prefer it for chronic allergic itch. That said, every dog is different — your vet will choose what fits your dog's case.

Can I get an Apoquel refill through RexVet?

Yes. RexVet veterinarians can refill Apoquel prescriptions for dogs who have a current vet relationship and prior diagnosis. Schedule a video visit and we'll send the refill through RexVetRx with same-day shipping.

What if I miss a dose of Apoquel?

Give the missed dose as soon as you remember unless it's almost time for the next dose. Never double up. If you miss multiple doses, itching typically returns within 24-48 hours.

Medical review by Dr. Tiffany Delacruz, DVM

Chief Executive Officer & Lead Veterinarian, RexVet. Licensed in Florida, New York, and Virginia.

Last fact-checked: 2026-05-19

Sources

This page is an educational reference and does not replace veterinary advice. Always consult a licensed veterinarian before starting, changing, or stopping medication for your pet.