* Anal gland infection or impaction
* Tail injury
* Arthritis or other joint problems
* Intervertebral disc disease
* Hip dysplasia
* Luxating patella
* Nerve damage
* Tumor or cancer
Behavioral problems:
* Fearfulness or anxiety
* Aggression
* Protectiveness of tail
* Dominance
* Lack of training or socialization
If you're concerned about your dog's behavior, it's always best to talk to your veterinarian to rule out any medical problems and get the best advice on how to address the behavior.