There's nothing that makes me smile more than watching a happy dog.

When a dog is wiggling and his tail is wagging wildly I'm filled with joy—and I think most dog owners feel the same way. That wildly wagging tail can get into trouble, though, and tail injuries can be tough to heal.

Let's Look at the Tail

The tail is an extension of the spine and is made up of vertebrae with joints and discs in between each one. The vertebrae, called caudal or coccygeal vertebrae depending on their position, get smaller the closer they are to the end of the tail. Muscles control the movement of the tail while nerves and blood vessels run throughout the tail all the way to its tip. Tail thicknesses and lengths vary according to a dog's breed or mixtures of breeds. Labrador Retrievers have a thick muscular tail that is full length but not as long as some other breeds, German Shepherds, for example. Great Danes and Greyhounds have a long, thin tail without much padding or hair coat. Some breeds have a natural shorter tail, often called a bobbed tail, that may be one half or one-quarter of its normal length. Some families of English Shepherds have this bobbed tail.

Doors Are Hard on Tails

Tails get caught in doors all the time. Doors in your home probably won't cause too much damage, maybe a scrape or a bit of soreness, because those doors usually aren't closed rapidly or with much force. Just check his tail for broken skin, run your hands down it to feel for any bones out of position, or for any swelling or soreness. Call your veterinarian if you feel something too far from normal—such as dislocated or broken bones, or if the pain continues. Car doors can cause a lot of damage to tails as car doors are usually closed with some force. A tail caught in a car door can be dislocated or broken. The symptoms of this will include a bent tail (no longer straight), perhaps no movement in his tail, and your dog will be in a great deal of pain. If you suspect a broken tail, veterinary care is needed right away. Car doors can also break the skin causing a great deal of bleeding. The skin may be cut or, if your dog pulls away while his tail is still caught, the skin can be pulled away from the underlying tissue. If bleeding is significant or doesn't stop, get veterinary help immediately.

Happy Tail Syndrome

A friend's Great Dane, Major, was diagnosed with Happy Tail Syndrome after several trips to the veterinarian with tail injuries. A big dog with a long thin tail, he was a happy dog and so that tail was always in motion. Without any coat to speak of and very little flesh on his tail to protect it, Major was constantly beating that tail up against walls, doors, furniture, and anything else he encountered. His height and strength caused the tip of his tail to remain injured almost all the time. The tiny blood vessels would leak and bleed and the skin would break down. Not only was he keeping his tail injured but his owner's house and car were covered in blood. Major had, over time, numerous stitches and many more attempts at bandaging his poor tail. Eventually, when he kept re-injuring it and veterinary care wasn't working, Major had to have a portion of his tail amputated. It didn't stop his happy wagging, but the shorter tail wasn't as vulnerable.

Nerve Damage from Pulling

Many injuries can cause nerve damage to the tail, but the most common cause is because of pulling on a dog's tail. Perhaps your dog is dashing out the front door and to stop him, someone grabs his tail. Although pulling on a tail like this is never recommended, in most cases the injury, if there is one, will be slight. However, in large dogs who are moving with a lot of power, the injury could be severe. Symptoms will vary according to the degree of injury, but often a tail will hang limply, without movement. In addition, dogs will usually have difficulty urinating and defecating. Veterinary care is absolutely necessary in these cases.

Minor Injuries

When you are brushing, combing, and bathing your dog, check his tail for burrs, foxtails, tangles and mats, and any injuries. By checking his tail regularly, as you do with your dog's teeth, ears, and paws, you can catch minor injuries early and care for them. Any minor injuries that occur during normal activities will usually heal without veterinary care. Keep minor cuts and scratches clean and check them regularly until they have healed. Soreness from rough play, or being stepped on, will also heal well at home. However, any injury that is out of the ordinary, such as potential broken bones, bleeding, apparent nerve damage, or other injuries need veterinary care to keep that tail wagging.