Unknown but possibly an autoimmune disease in those with genetic susceptibility and may be triggered by an environmental agent (Toxoplasma, Borrella, coxsackievirus).
The muscles begin to deteriorate when dogs are on a heavy dose of steroids such as Prednisone, often used to treat the polymyositis. My dog has polymositis, and has been on Prednisone for two months....
The formation of numerous, closely spaced rills due to the uneven removal of surface soil by streamlets of running water. Also known as rilling; rill wash; rillwork.