You will find a wide range of opinions on what dog breeds make good service dogs online, but unfortunately, the dog training industry is the wild west, and people who have plenty of time to use social media tend to not know too much about dogs and dog training.
Here are our thoughts. We are professional dog trainers, with dozens of service dogs personally trained and deployed for over 140 different tasks. In other words, we have the background and experience to back our opinions up.
High Drive Preferred
Most service dog trainers hate high drive dogs for service work because they can't channel said drive. We love high-drive dogs. They make some of the best service dogs if you have the experience to shape them. We prefer high-drive hunting breeds like retriever and herding breeds most.
Service dogs have stressful jobs. Helping a person with disabilities puts a lot of stress on anyone, including dogs. One of the biggest challenges with selecting the right service dog is reducing the risk of wash-out (meaning the dog can't handle said stress). What good is a trained task if a dog can't execute it when its handler has a seizure? Service dogs must be able to power through, which comes down to their genetics (i.e., the breeding). Dog breeds, which pet dog breeders predominantly breed, tend to have far poorer physical and mental health than dogs bred by sport dog and working dog breeders. The latter breeder group breeds for health and breed attributes and not for looks.
For this reason, a well-bred working dog usually has a more sound and stable mind than a dog from a pet dog breeder. That directly increases the odds for long, successful service work over its working life and reduces wash-out rates. Even the so-called runts from a great working dog litter still beat most pet dog breeding hands down. Genetics matter!
Further, herding and hunting breeds have above-level intelligence, which also makes a big difference.
But, these are generalities. What ultimately the right dog is, depends very much on the person and is very individual. So, selecting the right genetics is a crucial first step, but it's just the beginning. Here are some other important considerations.
Personal Preference: You must like the dog breed for you to become a successful team. If you don't like your service dog's breed, it will come through in your interactions, and it will affect your relationship.
Size/Height/Weight: Your dog must have the right size for the tasks as well as your living circumstances. These may be mutually exclusive, and then it gets tricky. For example, if you need a large dog for mobility reasons but live in a smaller apartment for the same reason.
Color: People are afraid of black dogs. Even black Labradors scare people. If you want your dog to help make new friends, a black dog can be a problem no matter how sweet he is.
Breed-Bias: Certain breeds will cause complications for you regardless of what the law says. For example, you can have a pit bull for a service dog, and no breed restrictions in apartments or stores will apply to you. But it will make your life more complicated, and certain places, like airlines, may still prevent you from flying until someone sues them for it and wins a large settlement.
Hair/Fur: Dogs with thick coats that shed a lot are more work to groom and will leave their fur all over your home. You must be okay with and be able to deal with it if you choose such a dog. Allergies from dog fur can also be an issue.
Health: Getting a healthy dog goes back to genetics. However, some breeds are prone to certain conditions even if DNA tests show no risk factors. Health impacts the dog's working life and potential care needs in older age. It is essential to understand all possible ramifications.
Biological Life Expectancy and Working Life Expectancy: Understand how long your dog will most likely be of service, when you need a new one, and how you can save up for it. Long-term planning is viral. Also, old dogs will have care needs of their own. Have a plan to manage that and possibly a family member that can help and give him/her a good pet life in retirement.
Based on the individual circumstances, the criteria can be even further complicated. Picking the right dog is essential for long-term success.
We prefer being involved in the dog selection process for all the stated reasons. However, we do work with other dogs after we outline the risks and challenges and an owner wants to move forward regardless. We would not accept an existing dog when the work would negatively impact the dog's health.