Complex sentence: Actually some these dogs are from humans that left the dog because those people don't want to take care of them anymore.Most of the 120,000 stray dogs in Bangkok are not aggressive, and many have been injured in traffic.
Split into simpler sentences: Actually some these dogs are from humans that left the dog because those people don't want to take care of them anymore. Most stray dogs in Bangkok are not aggressive, and many have been injured in traffic.