Immunotherapy is used in some cases in which the avoidance of the allergy trigger is impossible, if the dog has shown symptoms for approximately 5 months and if other treatments of Omega 3 and antihistamines do not work.
The dog then will be given skin tests to check for hypersensitivity. Once a trigger is found, the dog will be injected with altered antigens on a slow and steady basis. These are given either weeks or months apart, depending on the type. This helps the dog become desensitized to the allergic cause and can work well. Up to 80% of dogs show improvement.
In very serious cases where quality of life is being affected, steroid based medications may be given. This is given to the dog via injections or by oral form. Injections are usually given to a Yorkie with anywhere from a 1 week to a 6 month wait between shots. Oral steroids is sometimes preferred because if side effects appears, the oral does can be discontinued and the dog will stop having side effects rather quickly; once an injection is done, it can not be reversed. Oral steroids for Yorkies suffering from allergies are usually given for 3 to 5 days in a row and then evened out, usually every other day.
Steroid treatment is generally only given in severe cases in which all other efforts have failed. Why? Because of side effects. Each dog will react differently; however the most common side effects are weight gain, excessive drinking, increased urination, hyperactivity, panting, diarrhea and/or depression. Long term effects can be a drastic change to the coat, resulting in very dry coarse hairs. There may be skin issues and liver problems.