Q. Our Labrador has suddenly stopped wagging his tail. According to our veterinarian, he has what is called “dead tail,” which should heal on its own. What causes it? And can it happen again?

A. "Dead tail" is an accurate description: The tail literally hangs down, and the dog can’t wag it. The condition, also known as “cold tail” and “limber tail," is a muscle problem that happens when the tail is pushed to peak performance without first building up strength and stamina. Typically, it affects hunting dogs near the beginning of the working season or after a long day’s work. Swimming in cold water can also trigger the problem. Since the tail muscles work overtime to balance and steer, they can become exhausted.

The good news is that your veterinarian is right: The problem will resolve on its own in a couple of days with plenty of rest. Since the condition can be painful, your veterinarian may prescribe a nonsteroidal anti-inflammatory medication (NSAID) for your dog for a day or two to keep him comfortable.

To prevent a reoccurrence, take your dog on a series of shorter training sessions before attempting a full day of hard work or play. Veterinarians also suggest stretch breaks for dogs who are confined for lengthy periods, such as in crates while waiting for their turns to compete. It's also smart to halt strenuous activity before your dog is exhausted, especially if he's swimming in cold water.

This article was written by a Veterinarian.