Collars and leashes can cause strain on your dog's neck and throat. A dog harness, however, can help prevent injury and things like choking or hacking. In addition, a dog harness can be a perfect tool to use when you're walking, running, or hiking with your dog because it helps make these activities safer and more enjoyable for everyone involved.

Dog harnesses come in many different sizes and styles. It's important to consider all of your options and choose the harness that works best for you and your dog.

Dog size and temperament. Consider your dog's weight, character and breed to determine what size dog harness is best. Different styles of dog harnesses fit differently. You can measure around your dog's rib cage to ensure that you're buying the right size. Harnesses that are too tight can be painful for your dog, while harnesses that are too loose might be easy for your dog to slip out of. 

You want to be able to fit two fingers under all the straps on your dog, but you don't want to be able to pull the harness over the dog's head. You can test the dog harness by having your dog walk around your home with it on so you can make sure the harness isn't moving around on their body, loosening, or rubbing uncomfortably against their skin. 

Harness design. When choosing a dog harness, consider how much or how hard your dog pulls. The wrong harness can make it easier for your dog to pull you around. The most common types of dog harnesses include:

• Front-hook harness. This harness has a clip on the front of the dog's chest. It helps give you leverage as you walk with your dog because it's attached to the front of your dog's body. 
• Head halter. The head halter is designed to fit around your dog's head just behind the ears, while another strap fits around your dog’s muzzle. This style is good for large, strong dogs who like to pull. Because the head halter is placed around the dog’s muzzle, having it properly fitted is essential. It is not meant to be used to jerk or aggressively pull your dog. Rather, it’s intended as a tool to help gently guide your dog in the direction you want to go.
  

If your dog is well-behaved, a harness with a clip on the back is good. However, if your dog pulls, a harness with a clip on the front is better. This gives you more control so you can help your dog learn to walk next to you instead of pulling ahead. 
Features, size, cost, design, and materials all contribute to the cost of dog harnesses. You can expect to pay $15-$30 for the most basic, small dog harnesses, and around $35-$45 for fancier, large dog harnesses. The larger the dog harness, the more expensive it will likely be.

If you're unsure of what dog harness is right for your dog, consult your veterinarian.