They are sensitive, and need firm, but not harsh, training and discipline. This breed can be a chaser and should not be left off its lead in an unsecured area. Never leave a Cairn tied out, as he may fight larger dogs to protect his turf, sometimes with tragic consequences. Health Problems Do not over feed the Cairn for it tends to gain weight easily. Treats should be limited, even though the dog may be almost irresistible when begging.
Cairns tend to be allergic to fleas.
The Cairn Terrier will do okay in an apartment if it is sufficiently exercised. It is very active indoors and will do okay without a yard. This dog will get enough exercise running around a small yard, but if you live in an apartment, it will need a daily walk or a romp in the park. About 12-15 years. Brush several times a week, being gentle with the soft undercoat.