Retrospective evaluation of Apoquel® (oclacitinib) for the treatment of atopic dermatitis. Part 2: monitoring for side effects.

By Jon Plant, DVM, DACVD

In September I reported on the effectiveness of Apoquel® (oclacitinib) in controlling pruritus (itch) in the first 117 dogs that I had treated with this newish medication from Zoetis. When I prescribe Apoquel, I recommend obtaining a baseline complete blood count (CBC), serum chemistry, and urinalysis, with examinations and additional monitoring scheduled at 3, 6 and 12 months. There is no specific guidance from Zoetis or the FDA concerning monitoring the long-term use of Apoquel. This is the level of monitoring that I would do for my own dog taking this new drug, given that it modulates the immune system. Each veterinary practitioner will recommend what they are comfortable with and this may be influenced by experiences (positive or negative) and will likely evolve over time.

I selected several laboratory parameters to analyze over a 6-month period for 66 dogs. Note that this is not a rigorous clinical trial and may well suffer from selection bias. The parameters that I chose to present here are some of those that showed significant changes over time in some of Zoetis’ clinical trials, although in some cases at different time points than mine.









Descriptive findings: There was a slight decrease in the mean WBC count from day 0, but in none of the dogs did the WBC count fall below the reference range.

The dog with a WBC count of 25,700 at day 0 had generalized, severe pyoderma, a normal body temperature, and was extremely itchy (pruritus visual analog scale score of 10.0). We elected to continue Apoquel despite the elevated WBCs, as well as cefpodoxime.  At his 3 and 6-month examinations, the WBC counts and itch levels were back within normal ranges.

Among individual white blood cell lines, neither mean neutrophil nor mean lymphocyte counts were greatly changed during the 6 months of Apoquel therapy.

neutrophils and lymphocytes










Next time I’ll present data from these dogs for cholesterol, alkaline phosphatase, and globulin.

Have you had a chance to check out Itchology for iPhone?  It’s an easy and fun way for dedicated pet owners to chart their dog’s itch level and treatments, set medication reminders, and look for possible causes and effective treatments. Available on the Apple App Store or visit for a demo video and more information.

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About skinvet

Jon Plant, DVM, is a Diplomate of the American College of Veterinary Dermatology, founder of SkinVet Clinic and developer of RESPIT, regionally-specific immunotheray for atopic dermatitis of dogs and cats. He is a member of the International Committee on Atopic Diseases of Animals, the past President of the Portland Veterinary Medical Association and the Dermatology Section Editor of the Journal of the American Animal Hospital Association.
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11 Responses to Retrospective evaluation of Apoquel® (oclacitinib) for the treatment of atopic dermatitis. Part 2: monitoring for side effects.

  1. J says:

    Have you seen any dogs developed any skin growths since giving Apoquel during your studies? My dog has developed a single growth on the scrotum area after about 6 months of usage. It is not inflamed or ulcerated and hasn’t changed much in size and does not seem to bother him. He is on a very low dose (half a 5.4 mg tablet a day for a 31 pound dog). Just a little concerned now cause in the initial studies done there were a few reports of MCT’s, histiocytoma’s and undefined growths in some dogs.

    • skinvet says:

      Growths like this should probably be removed and biopsied, whether a dog is taking Apoquel or not. The real question is whether they are more prevalent in dogs taking Apoquel compared to a similar population that is not. So far, the evidence is not there to support that conclusion, because these types of tumors occur with some frequency in untreated dogs.

    • Stacy says:

      My dog (a pit bull mix) has been on Apoquel since it hit the market. He is still at the highest dose (10.8 2x per day – not FDA approved) as his itching returned to baseline levels immediately upon decrease and never improved. He has developed multiple growths – I had 7 removed and biopsied – all negative. He still has multiple growths all over his body, ranging in size from teeny (e.g., sesame seed) to quite large (e.g., cherry). Some are filled with blood and bleed upon impact. My vet thinks it is highly likely that the Apoquel is involved as it is an immunosuppressant. I don’t know what to think and am at a complete loss as to what to do for my boy who is still suffering terribly. The pros of Apoquel are that he stopped giving himself repeated staph infections, his fur grew back, and he has been able to gain and keep his weight on. The cons are – he is still terribly itchy and all these horrible growths. Other than his own feet, he eats nothing unless I make it myself (I don’t believe the results of the allergy test and so put him on an elimination diet to find foods that did not cause flareups). Once Spring hit – he’s declined rapidly. My vet and I are in the process of determining if another course of action isn’t more appropriate as I am thinking Apoquel just isn’t cutting it for my boy.

      • skinvet says:

        It sounds like Apoquel is not helping much, so I’m not sure why there is any hesitation to try something else. Seems like the thing to discuss with your veterinarian.

      • Stacy says:

        Yes – we are discussing options to determine the best course of action. Thanks

  2. My 11 yr. old Labrador has been taking apoqel for her allergies for a little over 2 months now. So far it seems to be working great for her itching. But in the last week and a half she has had 3 nose bleeds. Not sure if this is related to the medication or not. The nose bleeds only last for a minute or so. But she has never had this issue in the past. Any suggestions would be greatly appreciated.

  3. skinvet says:

    You are welcome!

  4. D says:

    Do you recommend Apoquel over allergy desensitizing shots? My dog is allergic to 3 grasses, 4 molds, dust mites, mulberry and hornets/wasps. I was also curious, he is allergic to Apergillus Mix, I noticed his food has Dried Aspergillus niger fermentation extract, should I switch foods?

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