Saint Bernards trace back to the Great St Bernard Hospice, high on an Alpine pass between Switzerland and Italy, where monks kept them from the late 1600s to find travelers lost in snow and fog. Today's dogs are giants, usually 120 to 180 pounds, with a massive head, loose flews and a smooth or longer coat in white with red or brindle markings.
That Alpine heritage is why Saints handle cold well and heat poorly, which matters in Clarksville's humid summers. They're known as calm, patient and gentle, but a dog this size needs early training, and you'll live with heavy shedding and drool. Their giant-breed health risks and 8 to 10 year lifespan are worth budgeting for.