Many people use the phrase "emotional support dog" so frequently that it can get confused with "service dog", but there are distinct differences between the two. Both are four-legged animals that help people, but that's where the similarities end.

Service dogs have been around for decades to help visually impaired people navigate their daily lives by helping them safely cross streets and avoid obstacles. They can help paralyzed people by retrieving items and alerting deaf people to noises like a crying baby. They can also assist people who are dealing with symptoms of social anxiety.

One major advocate of service dogs for social anxiety is James Middleton, brother in law of Prince William. He recently attended a GQ Men of the Year event with his cocker spaniel Ella as his date for the evening. While Middleton wore a tux, Ella sported a black and tartan "Pets As Therapy" jacket to publicize a UK animal therapy group. "Animals can provide a sense of calm, comfort or safety and divert attention away from a stressful situation and toward one that provides pleasure," he wrote on his Instagram page. "…developing a bond with an animal can help people develop a better sense of self-worth and trust, stabilize their emotions, and improve their communication, self-regulation and socialization skills."

A service dog undergoes extensive training to perform tasks that its owner is unable to do on their own due to physical, intellectual or emotional disabilities. They can see obstacles for people with impaired vision, hear things for deaf people or pick up objects for people with reduced dexterity. They can provide emotional support, but their main job is to provide assistance for their owners. They receive more legal protections through the Americans with Disabilities Act (ADA) than emotional support dogs and are legally allowed in almost every public space.

A study by Purdue University's College of Veterinary Medicine shows that overall symptoms of PTSD in veterans are lower for those with service dogs. Maggie O'Haire, assistant professor of human-animal interaction, says "we found that the group of veterans with service dogs had significantly lower levels of PTSD symptomology than those who did not. They also had lower levels of depression, lower anxiety and increased social participation, meaning a willingness to leave their house and go engage with society in different activities." Data gathered from the study has secured a grant for a larger-scale study on the effectiveness of service dogs for both military veterans with PTSD and their families.

Emotional support dogs are companion animals that provide therapeutic benefits for people with medically diagnosed mental, intellectual or physical disabilities. Owners can't decide for themselves that their pets meet these qualifications; they must have a diagnosis from a doctor or mental health professional, as well as a letter stating the benefits of ownership. There are nearly 40 conditions that meet these requirements, including anxiety, PTSD, and eating disorders.

Emotional support dogs are not required to receive any training before their designation, which makes people question their effectiveness. Without proper training, they may not behave as well as service animals, who know how to act in public. They receive fewer protections through the ADA, mostly only with housing and air travel. A home that says "no pets" can be forced to allow an emotional support animal, but restaurants and stores don't have to allow emotional support dogs into their buildings. Owners can carry their paperwork from their doctors, but that doesn't guarantee admittance into public buildings.

Determining whether a service or emotional support dog is right for you isn't something that should be decided quickly. Talk to your doctor about your specific situation to help make the decision that's best for your lifestyle.

Do you or anyone you know have either a service dog or emotional support dog? How helpful have they been?