I adopted a German Shepard 1.5 years old. He was left out in the back yard alone and developed this behavior where he runs in circles chasing his tail and barking and I can't stop him. Other times he just circles the yard or the furniture non stop.

Firstly well done for getting the dog out of its old life and hopefully inyto a much more fulfilling one!

Would need a lot more info before answering properly but heres a few ideas - apologies for hurried typingh.

Teach him a sit or down so that when he commences circling you can stop it by gettign him into a stationary position. Provide a bed in the room where the sofa is and train him to lie down on it and stay on it....

Avoid colourants n his food and chews!

Circing behaviour is common in digs that have been confined and bored, indeed all animals. What can happen is they can become physically addicted to the biological changes they can bring about in themselves when performing repetative patterns and then even when the need to do it is ceased, the addiction makes them carry on. SO.... what needs ot happen is we need to get your dog ADDICTED to better biological "hits" . Does he pay ball> Can you teach him to? What about agility ? great for solving ots of problems.... Tech him tricks..... Clicker tain him so that he can control his own reward rate a bit. Mak sure that when it is time for him to he gets ots of rest. Cage of necessary, if he doesnt ghet stressed by that. Rest is crucial to re learning new behaviours.

Instead of feeding his food in a bowl take it and throw it all over the garden so that his brain can be used in the way it was intended,m byu finding , sniffing, searching for and eating his food over a period of time. Consider Feeding raw bones for some of his meals - bones have a naturally sedating effect on dogs and the effort involved in eating them , can tire a dog .

Hope there is somethign ther to help. Good luck with your dog Denise