double muscling in dogs too

[knabe]

didn't know it occurs in dogs.  it also occurs to a small extent in horses.  a friend of mine used to have a peppy bred horse with an extra muscle over it's loin.  haven't followed that too closely, but apparently it was common to select for it in horses for a while.

http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=467985&in_page_id=1770