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