"Honey, I think the dog's tail is broken ! ! "

Excerpt from: "Cold Water Tail" by Diane O. Gifford

"Cold water tail," "limber tail syndrome," "broken tail," "dead tail," "broken wag" are all euphemisms for a relatively common occurrence in sporting dogs. The tail of the dog hangs down from the tail base or is held horizontal for three or four inches and then drops down. A flaccid tail episode appears to be a painful, but relatively benign affliction that can occur after swimming, after a heavy hunting day or even after a bath with cold water or water that is too warm. It is not always associated with swimming or water, but can happen after a heavy day of work that involves a lot of tail action. The majority of limp tail cases have been reported in sporting dogs or hounds -- Labrador Retrievers, Golden Retrievers, Setters, Pointers, Flatcoats, Foxhounds and Beagles are the breeds frequently named. Almost all dogs that suffer through an occurrence return to normal within a few days. Affected dogs may or may not have a repeat incidence during their lifetime. [It is this author's experience that symptoms will repeat in the same animal and can be triggered by something as simple as a cold water bath.] This affliction has been described by the layman as a "sprain," fibrosis or a "cold in the tail." The affected dog is miserable at the onset and the tail is painful. If neither the dog owner nor the veterinarian is familiar with this condition, it can be disturbing--fostering conjecture on a possible fracture or spinal cord disease.

Here's another good link.

As for Nutmeg, it wasn't until that evening after the swim that her tail went limp. You could really tell that it was uncomfortable for her to sit straight down on it. She was quick to shift all the way onto her hip. She did more standing or lying down during the 48 hours that her tail was too sore to lift. Hopefully if you see this with a similar onset you won't freak out and have to pay an unnecessary vet bill. Just be sure it is not something more serious before you dismiss it as something that will resolve on it's own. I always have on hand a herbal tincture called "trauma" from our holistic vet. It has arnica in it and other healing anti-inflammatory herbs. She got one drop every hour to two hours that evening then 4 times through out the next day. By the following day she was noticeably pain free and wagging her usual high and happy tail.