[1] Originally bred to control vermin including rats, rabbits, badgers, ferrets, foxes, otters, hares, deer, and even wolves, over time the Kerry became a general working dog used for a variety of jobs including herding cattle and sheep.

They have always been loyal and affectionate towards their owners and very gentle towards children but were often considered hostile toward other animals, including other dogs.

[citation needed] In the early days of competitive dog showing, the Irish Kennel Club required Kerries had to pass a "gameness" test, known as Teastas Mor certification, before they were deemed worthy of being judged.

[8] A 2024 UK study found a life expectancy of 12.4 years for the breed compared to an average of 12.7 for purebreeds and 12 for crossbreeds.

[9] The first literary reference to probably the Kerry Blue dates to 1847, when the author describes a dog that is bluish slate in colour, marked with darker blotches and patches, and often with black about the legs and muzzle.

The Irish nationalist leader Michael Collins owned a famous Kerry Blue named Convict 224.

Collins even made an attempt to have the Kerry Blue adopted as the national dog of Ireland.