Each 100 mg BOSULIF tablet contains 103.40 mg of bosutinib monohydrate, equivalent to 100 mg of bosutinib; each 500 mg BOSULIF tablet contains 516.98 mg of bosutinib monohydrate, equivalent to 500 mg of bosutinib.
Having said that, If your dog is itching and scratching all year long, then it's most likely due to either a food allergy or an allergy to something that is present all year such as dust mites or possibly even mange. In either case, you'll probably need more help to determine the cause which you can find here.
No other chronic skin problem is as intensely itchy as sarcoptic mange. You can hear the pet scratching throughout the house. Oozing, raw skin often causes off-white crusts to form that are very typical for sarcoptic mange. You can see them on the edge of the dog's ear in my illustration (by clicking the larger image).