How to Fit a Dog Collar on Your Service Dog

How to Fit a Dog Collar Correctly

April 2021 Dogs

Fitting your dog's collar is crucial for keeping them safe and happy. Finding the perfect collar fit is even more important for service dogs as they spend a significant amount of time wearing their collars and it is critical that they are comfortable so that they can focus on the job in front of them, and that they can be identified when accompanying you into "no pet" establishments.

Beyond comfort, your dog's collar carries their identification. If for some reason it falls off or your dog slips their collar, there is no way for your dog to be identified, returned to you, or even recognized as a service dog in some cases. That is why learning how to fit your dog's collar correctly is critical for your dog's comfort and safety.

Fitting a Collar

When you are fitting your dog's collar, the first step to avoid putting too tight of a collar on them is to use a cloth tape measure or even a string that you can make a marker on, to measure the circumference of your dog's neck. Once you have an initial measurement, you'll want to add between one to three inches for a comfortable fit.

Start with that measurement and put the collar on your service dog. Use the two-finger rule to make sure the collar is not too tight. Slide two of your fingers into the fastened collar. If two fingers do not fit, the collar is too tight, if you have much more room than two fingers width, you may want to tighten the collar a little bit.

Determine the correct collar width for your service dog

You do not want the collar to be tight, but it does need to be snug so that it does not slide over their heads when they are on a leash. Regardless of how hard your dog pulls on a leash they should not be able to slip their collar. There is a fine balance between snug and too tight, but you will find the sweet spot using the two-finger rule!

Collar Width

Another important consideration is how wide your dog's collar is. There are many collars that are only about half an inch wide while others are several inches wide. Keep in mind that width does matter for a comfortable fit. If your service dog's collar is too wide, it will rub on their skin and cause sores or discomfort.

The same goes for a collar being too thin. If you have a larger dog on a very thin collar, it is more likely to dig into one spot when they pull and cause discomfort. Thinner collars may also have a harder time holding your dog while on a leash. If your dog is on the larger or stronger side, you will need a wider collar to accommodate the pulling of the leash.

When you are picking out a collar, once you've fit the length be sure to feel where the top and bottom of the collar fall on your dog. If it is too wide and is pressing against their chest or chin, this is likely going to cause irritation and you may want to go down in width. Oftentimes you will be able to tell if a collar is too thin or too thick based on how it looks on your dog.

If you can barely see the collar through your dog's fur, it is too thin; if the collar is overpowering your dog and it drops down onto their chest significantly, you'll notice that the collar is too thick in width for them.

Fit Checks

Check the fitment of your service dogs collar

Remember that even if your dog does not look to have gained weight or gotten larger, you need to check the fit of their collar every once in a while. Collars can stretch and loosen overtime and if they are not checked, your dog may be able to slip their collar on your next walk or outing.

This is especially important on dogs with longer or fuller coats as their collars may be hidden by their fur. Always do a fit check after they have gotten groomed as they may have lost mass around their necks resulting in a loose-fitting collar. In addition, stay aware of how your service dog is growing.

They are not meant to have the same collar their entire life, and they will likely need different lengths and widths as they grow and their bodies change. If your service dog is not full grown yet, get into the habit of fit checking their collars often, maybe you check once a week to ensure it is not too tight and that the width is still accommodating their body size.

This will make sure that whenever they hit a growth spurt and start growing out of their collar, you notice right away and avoid any discomfort your dog may have.


Remember that your dog's collar is a daily accessory, and if it does not fit them properly, they are going to experience discomfort or potentially find themselves in a dangerous position. A loose-fitting collar is just as dangerous to a dog as a tight-fitting collar. Both present risks that can be completely avoided by fitting their collars correctly and checking often.

Getting into the habit of checking your service dog's collar consistently is just as important as measuring it correctly the first time around. When you are buying a collar for a puppy or a dog that is not yet full grown remember that it is just as harmful to try to put an adult collar on them as it is to try to keep them fitting in a puppy collar that they've outgrown.

Once again this is due to the width more so than the length of collars that are suited for adult dogs versus puppies. So instead, it is best to be prepared to buy several collars for your dog within their lifetime as they will not fit into their puppy or adult collars their whole life.

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