New dog, adolescent dog, older dog who has suddenly started doing something you cannot live with … when people need a trainer, where should they turn?

First, a caveat: If an adult dog’s behavior changes suddenly — uncharacteristic aggression, for example, see your vet to rule out any underlying health issues before deciding it’s a training issue.

I can make specific recommendations locally, where I know several excellent trainers. But more generally, here’s what I would suggest:

• Look at the trainer’s credentials. Anyone can advertise as a dog trainer. In a recent review of trainers in one area, nearly all of the websites I looked at gushed about the “trainer’s” love for animals and how they had dogs their whole lives. So what? That doesn’t make you a qualified trainer. The Certification Council for Professional Dog Trainers has widely recognized certifications that check knowledge or (much better but far less common) check knowledge and skills. A number of small or locally focused programs teach people training skills and knowledge; the APDT website has a helpful matrix comparing these.
• Look at professional memberships. Organizations like APDT (Association of Professional Dog trainers) and PPG (Pet Professionals Guild) require that people meet specific criteria to become professional members. While membership alone does not guarantee that the trainer has specific knowledge or skills, it does show that they care enough to learn and to jump through a few hoops more stringent than setting up a website or getting a business license.
• Trainers who also have some education on animal behavior and psychology get bonus points, especially for complex issues like aggression or anxiety.

When you’ve identified one or more possible trainers, interview them. Ask what their training approach is and what, if any, equipment they recommend. Avoid anyone who talks about “being the alpha” or showing the dog who’s boss. If a trainer tells you to put a prong collar on your puppy, run the other way. If you’re having a specific issue, such as high prey drive or excessive anxiety, ask about their experience with that problem. If they offer classes, ask if you can watch one.

Other resources to consider:

• Local dog training clubs — these can be wonderful or very disappointing. You might find a great selection of classes from trainers with broad-ranging experience. If there’s one where you live, it’s worth a visit.
• Recommendations from your local humane society or pet rescue — there might even be classes onsite, and shelter trainers are likely to have experience with dogs with a wide range of issues.
• Recommendations from friends with well-trained dogs — be careful here; your dog’s needs may be very different and your friend’s trainer might not be a good fit. But it’s certainly a place to start.

Notice that I am not suggesting that your vet is a great resource. She might be. She might not. As with nutrition, behavior and training are not areas where vets tend to get a lot of education — unless they specifically seek it out. Some do; many do not. If your vet is also a certified animal behavior expert then by all means, consult with her. Otherwise, she might not know any more about the local trainers or what would help your dog (behaviorally) than you do.

When you choose a trainer, pay close attention to your dog’s reaction as well as your gut feelings about how the first lesson(s) unfold. If your dog seems scared, don’t go back. I remember a friend telling me once that her dog ran and hid whenever the trainer came over. Clear sign that that was not the right trainer! And, obviously, if you don’t feel like you are making progress after several meetings, you might need to look for someone else. There are lots of great trainers out there, but it might take a few tries to get the right match for you, your dog, and the specific issues you need to resolve.