Choosing the Right Leash and Collar for Your Dog

When you bring a dog into your life, along with a water and food bowl, the first things you'll need to buy are a collar and leash. Most cities have laws about keeping dogs on leash when they're outside of your house or yard. But even if your hometown doesn't have a leash law, your pet will be safer if you keep him under control. Even the best trained dog can get distracted by a squirrel or cat and run into a busy street.
Collar Basics
For the most part, an everyday dog collar is a matter of taste and comfort. You can choose leather, nylon or cotton in any color or design you like. But every dog should have a comfortable collar that they wear at all times. The collar should include a tag with your contact information in case the dog ever gets out of the house or escapes your control on a walk. Depending on where you live, your dog might also be required to wear a license that you renew every year, as well as a tag showing that he's been vaccinated for rabies.
To choose the right-size collar, wrap a flexible measuring tape around the base of your dog's neck. It should be loose enough that you can slip two fingers underneath the tape. Note the measurement so you can pick the right size online or at the pet store. Most collars are adjustable through a range of several sizes, so even if your dog gets a haircut, the same collar should still fit.
The width of the collar will depend on the size and strength of your dog. Most collars will include information about width vs. dog size. Typically, collars are available in 3/4-inch, 1-inch and 1 1/2-inch widths. But you can find wider collars for strong dogs. The bigger the dog, the wider the collar should be for both comfort and control.

Certain breeds whose heads are narrower than their necks (particularly greyhounds and whippets) will need a special collar called a Martingale that tightens when they pull on it. Otherwise, they will slip right out of a regular collar.
For dogs that pull, it can be tempting to put them in a harness instead of using a traditional collar. A harness will relieve the pressure that a collar puts on a dog's neck, which is perfect if the animal has a neck injury or breathing problems. Otherwise, a standard harness can actually train the dog to pull more. If your dog doesn't know how to walk beside you on a loose leash, there are many tools you can use to help him learn this behavior.
Training Collars and Leashes
For puppies and adult dogs who never learned how to walk politely on a leash, there are many options to help them learn. Some of these tools are best used under the supervision of an experienced trainer. Others are safe to try out on your own.

Head Collar: Head collars, such as the Gentle Leader, make it more difficult for a dog to pull. Because this collar works more like a horse harness, no pressure is put on the neck. The Gentle Leader comes with a DVD that explains how to properly fit the harness to your dog and how to get him used to it. Some dogs will resist the strap that goes across their nose and take some time to adjust to the feeling. A well-fitting head harness will still allow the dog to open his mouth to eat, drink and pant, even though it looks a bit like a muzzle.

Anti-Pull Harness – Some specially designed harnesses, like the Easy Walk Harness, are created to prevent pulling rather than encourage it. The strap that runs across the dog's chest will actually move him to one side when he tries to go forward forcefully, which quickly discourages lunging. This type of harness is a much better choice for dogs with short snouts, like bulldogs and pugs, whose face shape makes a head collar impractical.

Rope Slip Lead: Some dogs need only a gentle correction to stop pulling, just a quick tug to one side. Slip leads allow you to offer such reminders without fear of harming the dog

Chain-Slip Collars: For dogs that require more than a gentle reminder, a chain collar might be necessary, but you should be properly trained in its use before you try this option.

Pronged Collars: They may look cruel, but for stubborn dogs, a pronged collar can be an excellent training tool once you've consulted an experienced dog trainer or behaviorist. The prongs actually prevent this collar from digging into the delicate trachea and, instead, apply even pressure all around the entire neck. It's important to ensure a perfect fit for this collar to be safe and effective.
Everyday Leashes
Like collars, simple leashes are largely a matter of taste. The width of the leash should match (or at least be close to) the width of the dog's collar. The longer the leash, the less control you'll have over the dog. Most leashes are 4-6 feet long and include a looped handle at one end to give you a good grip.
Leashes are typically made of nylon or leather but other materials are also available. Here are some of the pros and cons of each type:

Cotton Web: This is an inexpensive, medium-weight material that is strong enough for most dogs. It is generally comfortable to hold, but if your dog chews on the leash it might not last very long.

Nylon Web: Inexpensive and a bit more durable than cotton, nylon is strong but might not stand up to a chewer. This material can be a bit rough on your hands.

Chain: For dogs that try to chew on their leashes, chain is a good choice. A chain leash will usually have a leather or nylon handle to make it easy to grip. These leashes are more expensive and heavier.

Leather: A quality leather leash will stand up to the strongest dogs, as well as chewers. While these leashes are more expensive, they'll also last longer. 

Climbing Rope: Lighter than leather, this extremely strong material is suitable for the largest, strongest dogs. It is also comfortable on the hands.

Bungee: This flexible material is intended to help you control dogs who lunge by using their own strength against them, pulling them back toward you when they leap away. 

LED: If you typically walk your dog early in the morning or in the evening, a light-up leash is a good choice for safety. The LED lights along the leash will make you easier for motorists to see.
For dogs who lunge and jump, you can opt for a shorter leash that will give you extra control. You could also choose a leash with a second handle that allows you to switch to a closer grip in certain situations.
Retractable Leashes
Retractable leashes allow your dog to choose how far away he can roam, usually up to 26 feet. For a well-behaved, low-energy dog, this can be a fine choice. If your pet just wants to sniff around on short walks and doesn’t have strong reactions to other dogs, people or vehicles, a retractable leash might be just fine. However, many vets don't like these leashes because they give too much control to the dog and not enough to the handler.
Even though you can lock the leash at different lengths, if your dog gets into trouble when the leash is fully extended there's no way to quickly retract it to get control of your pet. This can be especially dangerous if your dog reacts strongly to other animals and people. He might get into a fight with another dog or jump on a small child, either of which could easily be avoided with a shorter, non-retractable leash.
If you're not sure what kind of collar or leash to choose, talk to your vet or trainer. You might also be able to get good information from a pet store. Just make sure the person you're accepting advice from is actually qualified to give it.
PetMD, "No More Retractable Leashes!", accessed on July 1, 2013.

Pet MD, "Puppy Checklist: Getting Off to a Great Start,", accessed on July 1, 2013.
Doctors Foster and Smith, "Which Collar is Right for You?,", accessed on July 1, 2013.

ASPCA, "Teaching Your Dog Not to Pull on a Leash,", accessed on July 1, 2013.