I have to admit that I am excited. There is a new drug on the market for the treatment of allergic skin disease in dogs, one of the most frustrating conditions that veterinarians deal with on a daily basis.
Allergic skin disease is also frustrating for owners and dogs because it can require repeat visits to the veterinary clinic and the long-term administration of oral and topical medications that sometimes have questionable efficacy and frequent side effects.
Veterinarians prescribe many different medications to control the itching caused by allergic skin disease. Antihistamines have few side effects (sedation being the main one) but are not very effective. Topical products such as medicated shampoos and sprays relieve some of the itch but provide only temporary relief. Fatty acids help to improve the skin barrier to some degree. Dogs tend to respond well to cyclosporine but may require a month or so to fully respond, and the medication is pricey.
The most effective and quickest-acting medications are glucocorticoids (steroids). However, steroids have the potential to cause serious side effects such as gastrointestinal ulceration, diabetes mellitus, pancreatitis, and Cushing’s disease. Steroids are generally safe to use in the short term (e.g., when a dog suffers allergy symptoms for just a few weeks out of the year), but the risks increase the longer a dog takes them.
New treatment options for allergic skin disease in dogs are always welcome, and one has just hit the market. Oclacitinib is a Janus-kinase inhibitor that reduces the production of cytokines (molecules that help cells “talk” to each other) that promote the inflammation and itching associated with allergic skin conditions. According the manufacturer, the medication selectively inhibits the Janus-kinase 1 (JAK1) and Janus-kinase 3 (JAK3) receptors but has minimal effect on the Janus-kinase 2 (JAK2)-dependent cytokines that are important in producing blood cells and providing immune function.
Oclacitinib is advertised as being effective at eliminating the itch caused by flea allergy, food allergy, contact dermatitis, and atopic dermatitis (itchy skin disease caused by environmental allergies). It supposedly starts working within four hours and can effectively control itching within 24 hours.
In a masked field study by the drug’s manufacturer, no significant side effects were seen. Any symptoms that developed were mild and consistent with the symptoms that developed in the placebo group, likely indicating a random event. The medication may be given concurrently with other medications such as nonsteroidal anti-inflammatories, antibiotics, vaccines, or allergy shots. It should not be used in dogs under 12 months of age because it can increase the risk of demodectic mange (a disease most frequently diagnosed in puppies), or in dogs with serious infections as it may decrease the immune system’s ability to respond.
I’ve not yet prescribed oclacitinib in any of my patients. I like to give a new drug a few months (at least) on the market before trying it out, but I’m looking forward to hearing what other vets and dog owners have to say about its safety and efficacy. It surely won’t be a magic pill that solves all of our allergy problems, but it sounds like it has the possibility of improving the lives of many chronically itchy dogs. Only time will tell.
Dr. Jennifer Coates