Sentence:  A spinal cord injury will confine him to a wheelchair for life. . . . He has a <WSD>service dog</WSD> and lives alone in a one-bedroom apartment, although there are relatives nearby. 
Meaning of the word marked with <WSD> tags:  A dog, such as a seeing-eye dog or a hearing-ear dog, which assists a person who is physically handicapped or who suffers from a mental disability such as post-traumatic stress disorder.