The main difference between a therapy dog and a service dog is their purpose. Service dogs are trained to assist their owners with a specific disability-related task. For example, a service dog might be trained to help a person with a physical disability to open doors and pick up objects.
On the other hand, therapy dogs are trained to provide affection, comfort, and support to people in hospitals, retirement homes, nursing homes, schools, hospices, disaster areas, and other settings. Therapy dogs do not have to be specifically trained to perform any type of task. Instead, they are trained to be gentle and calm in order to provide comfort and support to people in need.
Other important differences between service dogs and therapy dogs include the way they are trained and the length of the training. Service dogs need to be trained for a minimum of 120 hours over 6-12 months, while therapy dogs can usually be trained in less than 100 hours.
Service dogs must also pass a public access test to demonstrate that they are able to remain calm and focused in public settings, while therapy dogs do not need to pass such a test. Additionally, service dogs are allowed access to public places with their handler, while therapy dogs are not.