The description of the Glen of Imaal Terrier as an antique breed is probably apt in terms of character as well as conformation. The Glen has retained its qualities of versatility, intelligence and ruggedness. This is not a cookie-cutter breed, and even within a litter there is often variation. Its character and temperament are best described as complex.
It is a tough and fearless dog, and before the badger trials were outlawed in Ireland in 1966, the Glen was required to earn its "Teastas Misneach," or Dead Game Certificate, in order to win a Championship. This meant silently drawing a badger from its den within a specified time. The Glen tends to be a quiet dog in general, barking only when necessary, although a Glen wanting your attention or bemoaning being left alone can have an enormous vocabulary.
In play, Glens tend to prefer games of tackle over tag. While possessing the energy and tenacity of terriers when called upon, the Glen of Imaal has an un-terrier-like, laid-back temperament. It is affectionate and easy-going.
Most Glens are gentle, friendly and trustworthy with children, patient, and not constantly demanding attention. It loves to play, yet also knows how to sit calmly and wait patiently for attention. Although a Glen may choose a special person, it works well as a family dog. It is often happy to make friends with whomever is willing to pay it attention. It is loyal and tends not to wander, and in fact prefers physical proximity to its owner.
It makes an excellent companion and learns quickly, always impressing obedience instructors, although Glen of Imaal Terriers can get bored with formal obedience routines if you are not careful. Glens love agility and earth dog activities, and also make excellent therapy dogs.
Glens have character. They are thinking dogs, and quickly understand what their owners want. They love to please their owners and respond best to positive reinforcement, such as words of praise or a pat, for jobs well done. A verbal scolding is usually sufficient reprimand.
Sometimes, however, Glens can be quite stubborn. Owners must be prepared to be firm and consistent. It is usually best to avoid treats for training Glens, so they don’t over-focus on food and owners don’t get in the habit of bribing Glens to do their bidding.
We have found the Glen to be an easy dog to live with. It does not thrive in kennels, preferring a human environment where it can use its intelligence and enjoy its owners’ companionship. It has few parallels as a weather-hardy, working dog. Adult Glens can easily handle two-mile walks.
Most Glens enjoy riding in the car and do not need tranquilizers for airline travel. Veterinarians who meet Glens marvel at their calm temperament, even as puppies.
Strong dogs both physically and mentally, Glen of Imaal Terriers regard themselves as large dogs and have a hard time imagining that anything–a bigger dog, a car–could hurt them.
Be very careful around roads. As earth dogs, Glens are comfortable being underneath things, and being short, can see right beneath the undercarriage of a vehicle to the other side. Good fences are the best way to prevent problems.
Glens usually prefer to avoid a fight but are fully capable of defending themselves. Some Glens become dog aggressive as they mature, either by nature or in response to aggressive acts by other dogs. Good early socialization and firm guidance may help to avoid this but owners should be observant and use common sense. Occasionally Glens have been known to kill small, yappy, dogs in their own households when they got fed up with the noise and aggression. Glens have also been known to kill cats, raccoons, skunks and porcupines.
However, Glens will usually get along well with other dogs, cats, birds and other pets if they are raised with them from puppy hood. On several occasions we have also successfully re-homed certain adult Glens with cats, depending on the individual dog and knowledgeable owners.