An assistance dog is a dog that receives specialized training to aid an individual with a disability in navigating everyday life. Assistance dogs can be trained by an organization, or by their handler.

'Assistance dog' is the internationally established term for a dog that provides assistance to a disabled person and is task-trained to help mitigate the handler's disability. In the United States, assistance dogs are also commonly referred to as 'service dogs'.^[1]

Assistance dogs are not emotional support animals (ESAs), which are generally not protected by the same laws^[2] and typically have little to no training compared to an assistance or service dog. Assistance dogs and ESAs are also both distinct from therapy dogs. While therapy dogs are required to undergo training and become certified, they work for people other than their handler and are not covered by laws such as the US Americans with Disabilities Act.^[1][3][4]

For a dog to be considered an assistance dog, they must meet the following criteria:

1. The dog's handler must meet the legal definition of disability in a specific country or region.
2. The dog must be specifically trained to mitigate the handler's disability in some way, e.g. opening doors, detecting high blood sugar or allergens and notifying of such, alerting to a ringing phone or other audible stimuli, and assisting those who are visually or mobility impaired.^[5]
3. The dog must be docile and well-behaved, as well as clean and healthy.

Individual countries and regions will have specific laws and regulations, with these international criteria having broad recognition across the globe.^[6][7][8]

Assistance dogs have traditionally been trained by organizations, but in countries such as the United States, United Kingdom, and Australia, assistance dogs can also be trained by their handlers.^[9][10][11]

A prospective assistance dog candidate will go through socialization and desensitization training, where the dog is exposed to unfamiliar locations, sounds, scents, and other stimuli. This training sets the foundations for the assistance dog to remain focused while working. An assistance dog prospect will also go through obedience training to ensure they remain under control of the handler.^[12]

After completing obedience training, an assistance dog commences specialized task training. During this training, the assistance dog will learn to perform tasks that will aid their disabled handler. The tasks that an assistance dog is trained to perform will differ based on the handler's disabilities and needs.

Examples of tasks include alerting to a fire alarm or doorbell, retrieving a medication during a medical episode, pulling a wheelchair, retrieving an item that has been dropped by the handler, and turning on lights. Some tasks may require a larger dog with healthy joints, while others (e.g. alerting to a sound) can be performed by a dog of any size.^[13]

Common examples of assistance dogs include:^[14]

• Guide dogs
• Hearing dogs
• Mobility assistance dogs
• Medical response dogs
• Seizure response dogs
• Psychiatric assistance dogs
• Autism assistance dogs

In the United States, the Americans with Disability Act states that there is no formal certification or registration required for a dog to become an Assistance Dog.^[15] State and local governments, businesses, and nonprofit organizations that serve the public generally must allow service animals to accompany people with disabilities in all areas of the facility where the public is normally allowed to go.^[16]

• Delta Society's National Service Animal Resource Center