Limber tail is a poorly understood condition that affects sporting breeds such as Retrievers, Pointers, Beagles, and Setters. Its formal name is acute caudal myopathy, but it is also referred to as cold water tail, sprung tail, and dead tail. It is characterized by a tail that just hangs limply and doesn't wag. Some individuals hold the base of their tail out horizontally and then the remainder hangs loosely.
An early study into the condition showed that affected dogs had high levels of creatine kinase in their blood. This enzyme is released from damaged muscle cells and this finding, coupled with the lack of any tail or spinal damage on x-rays, suggested that it is associated with muscle trauma. Biopsy of tail muscles confirmed that muscle fiber damage was present. The current recommended treatment for dogs with limber tail is anti-inflammatory medication and rest. It appears that giving the medication in the first 24 hours after symptoms appear is most effective.
The DogsLife project is an initiative that follows the health of around 6000 Labrador Retrievers in the United Kingdom. It allows researchers to look at the incidence of a number of medical conditions over the years, which may give some insight into predisposing causes. Scientists from the University of Edinburgh used this resource to compare dogs that suffered from limber tail to those that didn't, and they noticed a number of similarities between affected dogs. They also found that the incidence of unexplained tail limpness was almost 10% in the dogs they studied, which is quite a significant figure.
First, working dogs, including hunting and herding breeds, are more likely to be affected than other breeds. They often develop limber tail on the first hunt or the first long working session of the season when they aren't yet used to the increased amount of exercise.
Second, limber tail is more likely to affect dogs in colder areas, such as the more northern parts of the United Kingdom. It's particularly common in dogs that retrieve in water because the temperature is usually lower than that of the environment. This agrees with the anecdotal evidence that suggests that the cold plays a part in the development of limber tail.
Lastly, there could be a genetic link to limber tail. The scientists found that a number of the dogs affected were in fact related. This finding may enable breeders to choose appropriate dogs for their breeding program that will reduce the incidence in their offspring.
While limber tail isn't a permanent affliction, it can cause discomfort and prevent a dog from working for a number of days or even weeks. To reduce the chances of a dog being affected, pet parents need to acclimatize their dog to cold temperatures before letting them work all day and also minimize the amount of time they're swimming in cold water. Similarly, the hounds should build up gradually to long periods of exercise and be rested regularly if possible. Interestingly, one study suggested that being crated for long periods could contribute to limber tail, so frequent breaks during transport are important.