I fed mine a lot of worms, but I also fed him mice from time to time 
I know a lot don't agree because of the fat and red meat and blah blah, but think about it. My wolf was a true monster very very aggressive. Don't think for a second in nature that they don't eat rodents or birds or anything that moves across the water. Earth worms would be less lkey to come by than an occasiol rodent swimming across the water. One word of caution though. It gets messy with the hair

I know a lot don't agree because of the fat and red meat and blah blah, but think about it. My wolf was a true monster very very aggressive. Don't think for a second in nature that they don't eat rodents or birds or anything that moves across the water. Earth worms would be less lkey to come by than an occasiol rodent swimming across the water. One word of caution though. It gets messy with the hair
