The Perro de Presa Canario, also known as the Canary Mastiff, is a rare large Molosser-type dog breed originally bred for working livestock. The name of the breed is Spanish, means 'Canarian catch dog', and is often shortened to 'Presa Canario' or simply 'Presa'. Presas require early socialization and obedience training. In some situations, the Perro de Presa Canario can be aggressive toward other dogs and suspicious of strangers. In the past these dogs were used in dog fighting rings due to their size.