1 Canker sores are small, painful ulcers on the inside of the mouth, tongue, lips, or throat. 2  Symptoms of canker sores include small, painful, crater-like ulcers.  See a doctor if canker sores are accompanied by fever, last more than three weeks, or the affected individual has difficulty swallowing.
When people think of wolves, one species usually comes to mind: the gray wolf. The gray wolf is the largest wolf and the basis of legends. According to National Geographic, the breed was almost hunted to extinction in the lower 48 states of the United States. Even now, few exist outside Alaska.
Wolves are the ancestors of all domestic dogs. There are two species of wolves in North America. The smaller species is the red wolf, Canis rufus, which has shorter, redder fur than the gray wolf. The gray wolf, Canis lupus, has thicker fur which is more gray or golden, and is larger than the red wolf.