Wolves will eat any type of meat from deer and mice to fish and even livestock. They are carnivorous animals that only eat meat and will eat any type of meat they can find.
Many people think of wolves as violent and dangerous creatures, but they are simply predatory. They will search to find anything they can for a meal, whether it is a human or not. The main component of a wolf's diet is deer, but they will sometimes eat mice and birds when they are looking for something supplementary. Wolves that live near rivers and streams will occasionally search for and eat fish if they cannot find deer or other, larger animals.
Wolves will often kill their prey ahead of time and let it sit while they prepare to eat it. This most commonly occurs when there is deep snow or during a particularly cold winter. They do this to help them in the event that there is no more prey to catch. They will also kill prey and bury it to eat later.
It is not uncommon for wolves to eat livestock and they will generally be drawn to places that have a large amount of livestock. While human activity can help keep the wolves at a distance from the livestock, they may still come to prey on cattle, sheep and even horses.