Service dogs are life-changing, but they can be very expensive, so more and more people are choosing to owner-train their dogs. The question then becomes should you get a puppy, an adolescent, or an adult? My recommendation is to get a dog that’s 2-3 years old, with a known temperament and vet checks, but each age has its pros and cons.
Why do I recommend starting with an adult dog? It’s much easier and, in general, less stressful. Puppies go through several behavioral changes and fear periods and dogs aren’t physically mature until they’re around 1.5-2 years old (depending on size, sometimes longer). So any task or work that may be physically demanding, even sometimes jumping up and off of things, needs to be postponed until the dog is physically mature and it’s safe to do that kind of training. It’s far too easy to have a young dog, even one whose parents were health-checked, and end up with a dog who maybe isn’t right for you or isn’t able to work at all. My second service dog had a very short career due to bad hips and knees, even though he was bred to be a service dog and had the perfect temperament.
The fear periods that both puppies and adolescents go through can also be very rough. It’s far too easy to have a dog that was a perfect candidate turned into a dud because something during a fear period was handled incorrectly. Even if a dog isn’t ruined, it can cause stress and frustration continuing into the future for you and your service dog. For example, my current service dog is nervous around cars. It’s not a debilitating fear and he’ll get into vehicles, including buses and planes, without resistance, but there’s low level anxiety that stresses him out when he works around cars and trucks. It happened during a fear period: I pushed him too much when it came to his nervousness around cars and it’s now much, much stronger and has taken a lot of work to help him be more calm around cars.
Unfortunately, starting with an adult generally requires you to go to a rescue or shelter. Most dogs don’t display their real temperaments when in crowded housing, especially in the non-home-like situation that shelters generally have their dogs in. So you’ll need the help of a professional dog trainer who has gone into shelters before and can evaluate the dogs for their true temperament. There’s a reason that there’s a “honeymoon period” with rescue/shelter dogs, and that’s because it takes time for them to show their true colors. Most rescue/shelter dogs also don’t do health checks (or they do very minimal ones). So, it can be a risk getting an older dog, though looking carefully at all of the notes they have on the dog and getting professional help to evaluate the dog can be a good starting point.
The good thing about starting with a puppy is that you can do thorough research on the parents. You can make sure that their parents have good or excellent responses on all the health checks. You can make sure the parents come from good stock, with stable temperaments. You can generally get help from the breeder themselves with looking through the puppies and determining which, if any, may have a good temperament for being a service dog. However, even if you find the perfect breeder and the perfect parents, that doesn’t mean that the puppy you choose (or are given) will be perfect.
Puppies go through several stages, which include temperament changes. A puppy who seems to be doing everything right at 2-4 months old will suddenly turn into an adolescent and may seem like they’ve lost all of that training you were working so hard on. A puppy who tested perfectly, as mentioned above, will also go through fear periods that may lead to unexpected complications, even up to having to wash a puppy.
Puppies also require a lot more time and energy than adults. For someone with one or more disabling conditions, this can mean that puppies are even more draining and exhausting to care for, let alone train. There’s also a lot of pressure and anxiety that goes along with training a puppy or adolescent dog: what if you mess up? What if you were wrong about this dog? What if you have a couple of bad weeks and can’t do as much training?
Generally, adult dogs can be trained faster because they don’t go through the behavior changes that younger dogs do. They’re also cheaper, if only because you don’t have to get various sizes of the same toys and equipment. Therefore, they tend to be less stress- and anxiety-inducing than starting with a younger prospect. However, if you’ve raised a puppy before, have a strong support network, and are prepared for the various changes that puppies go through, it can be nice to start with known stock.
Any way you go has some challenges. I’ve just found, personally and through many clients, that starting with an older dog is generally less stressful and less draining. With that said, do what is right for you. And always be ready to reach out for help, if you find you need it, whether that’s a professional dog trainer, the breeder, or a family member.