Skip to Content

How Can You Tell When a Flat Collar Has Been Properly Fitted On a Dog?

You would assume that dog collars are a simple thing. However, there are so many types, styles, sizes, and functions of dog collars available for your canine companion. Dog collars can be complicated, but the proper-fitted flat collar shouldn’t be. So just how should a flat collar fit on a dog?

Dr. Jess will answer this common question below:

brown leather dog collar on a leash with no dog

What is a Dog Collar?

A dog collar is a piece or strap of material that is fitted around a dog’s neck in order to lead them, contain them, or control them.

It has many functions such as:

  • Leading: Most dogs, after getting used to a collar and lead, will easily be lead from point A to point B, with just their collar and lead. Then there is no herding necessary 🙂
  • Containment and/or Restraint: to contain the dog without the need for a crate, kennel, or other enclosure
  • Identification: Many types of dog collars have a clasp attachment to use to attach a license and other identification of the dog in case the dog gets loose or runs away. Think of this as your dog’s student I.D. or drivers license, don’t leave home without it! In many areas it is a law to have your dog wearing a collar with license and other health or vaccine-related information on it.
  • Fashion: Many dogs wear collars as fashion or accessories as part of a costume or outfit. Sometimes these types of collars look and act more like a necklace than an actual dog collar.

A dog collar is typically attached to a lead rope of sorts, usually referred to as a leash, to connect to the dog, typically during transport from one location to another, such as during a walk outdoors.

Most leashes are somewhere between 4 – 10 feet long and can be retractable or fixed.

Types of Dog Collars

There are many different types of collars out there, most serving slightly different purposes. Some of the more popular types of dog collars are:

  • Buckle or Flat Collars: This is the traditional type of dog collar and the collar I am focusing my attention on today.
  • Breakaway Collars: These collars are very similar to buckle collars except that they also have either a strap or buckle on the collar that will break if enough force or pressure is ut behind it. These are used if a strangulation hazard is a concern.
  • Safety Stretch Collars: These collars have an elastic piece or strap along the collar to allow for a certain amount of stretch or give to take place when under pressure.
  • Lighted Collars: This collar provides a light source on the collar to allow your dog to become more visible to others at night or in dark situations.
  • Reflective Collars: Reflective collars have the same function as lighted collars, allowing your dog to become more visible in certain situations when light hits a reflective piece on the collar and bounces off the reflection, making the collar visible to others.
  • Floatation Collars: These act as a buoyancy aid, and are different from doggie life jackets.
  • Martingale Collars: These collars are made for those dogs who have a tendency to slip out of their normal buckle or flat collars and have a second smaller loop to help tighten and enclose the collar around the neck if the dog tries to slip out.
  • Flea Collars: These collars contain chemical substances to help fight off flea infestations that are on your dog.
  • Head Collars: Also known as ‘head halters‘, are a type of collar that has a strap that goes around part of the face, usually wrapping around the nose, such as in the Gentle Leader brand of head collars.
  • Shock Collars: Are meant to be electronic training aids that release an electric signal or vibration or sound when training.
  • Prong Collars: These collars are also widely known as ‘pinch collars‘ and is designed to help prevent pulling.
  • Choke Chain Collars: These collars are made up of a silver chain and two loops on either end and allow more or less pressure put on the chain around the neck depending on how much pressure is applied to the leash that the collar is attached to.

Does My Dog Need A Collar?

Does your dog need a collar….

I’m going to go with yes.

Your dog should have a collar.


Unless there is a valid veterinarian-approved reason your dog should not have one.

I can think of two different canine cases in my years of medicine where I warranted the pet to not wear a collar due to case-specific medical concerns.

Just TWO cases!

Wear that darn collar…. and wear it correctly!


Well because it can help with, 1. restraining your dog, 2. identifying your pet when lost.

You will likely think that these two reasons are not a real scenarios for you and your dog…. until they are.

Dogs get loose. And dogs have emotions and reactions that can lead them to react when we are least expecting it.

So having your dog wear a collar is protecting them, yourself, and others.

What if the Collar is Too Loose?

jack russell puppy wear an oversized adult dog collar

1. Dog on the Loose!

Dogs with collars that are too loose are very quick to figure out that they can easily get out of them and slip away.

All that they need to do is either drop their nose to the ground and let gravity drop the collar from their necks, or they need whomever is on the other end of their leash to put on a little pressure while they back up and out of their loose-fitted flat collar.

Then you have a loose dog on your hands. This is a very dangerous situation for many dog owners.

2. Mouth or Leg Injuries:

If your dog’s collar is too loose, then your pup has a greater chance of getting one of their cute paws, or their jaw, caught up in the extra sag of their collar. This could lead to mouth, jaw, teeth, and/or leg injuries. Ouch!

3. Skin Irritation or Inflammation:

Skin irritation may occur from a collar being too loose and rubbing loosely against the skin of some dogs.

What Happens if it is Too Tight?

chihuahua smiling wearing a tight red collar

1. Choking:

If the collar is too tight, it can start to close off the airway leading to asphyxiation (choking) if severe.

2. Skin Irritation:

Skin irritation may occur from a collar being too tight and rubbing tightly against the skin of some dogs.

3. Neck muscle or Trachea Injury:

Injury can occur from the canine either straining or twisting their head or neck to relieve pressure from the collar or from a heavy pressure burden put on the trachea (their wind pipe).

How Do I Know It Is A Correctly Fitted Flat Collar?

white and brown dog with yellow collar being measured by human hands

A normal dog collar should be snug but not too tight, there is a rule called the Two Finger Rule.

This rule instructs you to take your pointer and middle fingers and slide them in between your dog’s collar and their neck.

If your fingers slide in easily but are snug between the collar and neck, the collar is a good fit.

If your fingers can’t fit without force, the collar is too tight.

If your fingers are not snug to the neck one inserted, then the collar is too loose.

Adjust the collar accordingly, checking routinely to make sure that the proper fit is maintained at all times.

fitting flat dog collar properly

How To Measure For A Dog Collar

Active Time: 1 minute
Total Time: 1 minute
Difficulty: Easy
Estimated Cost: Free


  • flexible measuring tape


    1. Take a cloth or flexible measuring tape and measure the circumference of your dog’s neck. Use this measurement as a guide when purchasing your dog's collar.
    2. Once on, take your pointer and middle fingers and slide them in between your dog's collar and their neck.
    3. If your fingers slide in easily but are snug between the collar and neck, the collar is a good fit. If your fingers can't fit without force, the collar is too tight. If your fingers are not snug to the neck, then the collar is too loose.
    4. Adjust the collar accordingly, checking routinely to make sure that the proper fit is maintained at all times.


If you do not have a flexible tape measure of some kind then you can use a piece of string, ribbon, even a men's tie or a shoelace!

Side Effects of an Ill-Fitting Flat Collar

I’ve already mentioned choking, skin irritation, neck muscle injuries, or mouth or leg injuries to name a few.

How Often to Check Collar Fit

A good rule of thumb is to regularly check your dog’s collar to ensure that their collars are properly sized for them as well that they are in good repair.

I personally check my own dog’s collars right before each daily walk that we take through our neighborhood.

And if you still aren’t sure, ask your vet. They won’t mind double checking for you, trust me!

veterinarian signature
Skip to Instructions