Long term use of corticosteroids can have many side-effects and is the reason why we don't like to use them long-term in pets. This dog is suffering from calcinosis cutis which is caused by calcium being deposited in the subcutaneous tissue and the video shows the surprisingly nasty changes this can cause in the skin. The good news is the dog will get better once the effects have worn off. Yay!
Love... and other stuff too