The Irish Wolfhound is considered to be the largest breed of dog. Male Irish Wolfhounds average between 36-40"(85-90cm) at the shoulders(withers). The average life span of an Irish Wolfhound is only six and a half years. Because of the large size and short lifespan of this breed, the Irish Wolfhound has a phenomenal growth rate as a puppy. When fed a proper diet, Irish Wolfhound puppies can grow over 3/4"(2cm) a week in height, and gain up to 1 pound(.45kg) a day. Irish Wolfhounds can grow to full size in as little as 8 months, although they are still considered puppies until 18 months old.

There are tales of Irish Wolfhounds being used in war to dismount warriors from the backs of horses, and of the dogs chasing lions away in Africa.