[Yogi and mamma]

Yogi has been on the Natures Variety Raw for a month now and he has been eating venison and beef (i switch off every 2-3 weeks) and lately he can hold it he just goes in the house. Its very watery sometimes nothing comes out but water and his poop is very watery. i know this is kind of a gross thing to talk about but i dont know whats wrong here. when he poops its like a dark brown color with little white things in it?! does anyone have this problem? i dont know what to do i thought this was a good food