You may be spending more time with your pet, and wondering about some of those weird things they do, such as chasing their tail!
There are many possible explanations. Puppies might just be intrigued and chase it for fun. Other dogs might do it out of boredom or due to pent up energy. In some cases, it can be due to compulsive behavioural problems, or be a sign of pain or irritation around the bottom. If the tail chasing seems excessive, or you notice your dog biting or licking their back end a lot, contact your vet to discuss.