My neighbors starve and abuse their dogs .. What should I do ?

My neighbor hits his dogs for no reason everyday. He leaves them outside in the freezing cold with no food or water ): and today I was walking my dog around the yard and i saw his husky and she was skin and bones and she wasn't moving I went over there and she was tied to the back porch on a leash the was about 3 feet long and her head was stuck in the porch so I called the husky's owner he came outside untangled her and jerked her across the yard she wasn't walking cause she was to weak and he drug her around like she was nothing ): please help what do I do .. ?