Correct Collar Fit: The Simple Safety Check Most People Miss
A dog collar seems like such a basic thing, until it isn’t.
At Jordan Dog Training, we very regularly see collars fitted too loosely. Most people are not doing anything “wrong” on purpose, it’s usually just one of those everyday details that gets missed. But collar fit matters more than people realise, and getting it right can prevent some genuinely scary moments.
This blog is a practical, generic guide to help you check your dog’s collar fit and understand what can go wrong when collars are too loose or poorly fitted.
Why collar fit matters
A correctly fitted collar should sit comfortably, stay in the right place, and do its job without creating risk.
When a collar is too loose, it can cause real safety issues, including:
1) Collars slipping off
Loose collars can slide straight over a dog’s head. This is especially common if a dog:
- backs up quickly on lead
- spooks at a sudden noise
- does the classic “drop the head and reverse out” manoeuvre
- has a narrower head than neck (some breeds and individuals are built this way)
A collar that can slip off is basically a collar you can’t rely on when it matters most.
2) Collars getting caught in the dog’s mouth or legs
This one surprises a lot of people, but it happens more than you’d think.
If a collar sits too low or rotates around easily, a dog scratching at their neck can sometimes catch a paw, toenail, or even a tooth in the collar. Some dogs will then panic and thrash, which can lead to:
- physical injury (rubbing, cuts, pulled nails)
- fear around handling
- fear of the collar itself
- a dog that becomes reactive when anyone touches their neck area
Even if no injury happens, a single scary incident can create a lasting emotional response.
3) Rubbing and discomfort (even when “loose”)
A collar that moves around too much can still rub. Especially on dogs with:
- finer coats
- short coats
- sensitive skin
- lots of movement on lead (pulling, spinning, bouncing)
The collar does not need to be tight to irritate the skin if it is constantly shifting and friction-building.
The two-finger rule (the simplest starting point)
A good starting guideline is the two-finger rule.
- You should be able to slide two fingers between your dog’s collar and their neck.
- Those fingers should fit snugly, not with heaps of spare room.
A quick way to think about it:
- If you can comfortably fit three or four fingers, it’s usually too loose.
- If you can barely fit one finger, it’s usually too tight.
This is a general guide, not a perfect science, but it works well for most dogs as a starting check.
Where the collar should sit
In most cases, a flat collar should sit:
- high on the neck, not down near the shoulders
- comfortably behind the ears
- in a position where it doesn’t spin freely with every movement
If the collar drops low and rotates easily, it’s usually a sign it’s not fitted well for that dog, or the collar style is not ideal for their shape.
Why “perfect fit” varies so much between dogs
There are a lot of individual differences that affect collar fit, including:
- breed and body shape (blocky heads vs narrow heads)
- coat thickness (especially double-coated breeds)
- age (puppies grow fast)
- weight changes
- skin sensitivity
- collar type and width
So what we’re sharing here is generic guidance. Some dogs genuinely do better and safer in a different collar style (for example, a properly fitted martingale-style collar for dogs that can slip flat collars), and some dogs are better managed with a harness for day-to-day walking.
The key message is not “one collar fits all”, it’s check the fit and check it often.
A simple collar-fit checklist
Here’s an easy routine we recommend:
Step 1: Do a fit check at home
- Put the collar on and do the two-finger rule check.
- Make sure it sits high enough on the neck and doesn’t drop low.
Step 2: Do a “slip test” safely
With your dog calm, gently test whether the collar can slide forward over the head. If it looks like it could come off with a quick backing motion, it’s too loose or not the right style.
Step 3: Check after activity
Re-check collar fit after:
- walks
- zoomies and play
- grooming
- swimming (wet coats can change how a collar sits)
- big training sessions
Step 4: Watch your dog’s body language
If your dog is:
- scratching constantly at the collar
- rubbing their neck on the ground
- avoiding handling around the collar area
- showing redness or hair loss under the collar
…take it as a signal to reassess fit, collar type, and whether a vet check is needed if irritation is present.
Common mistakes we see (and how to fix them)
“I leave it loose so it’s comfortable”
Totally understandable, but collars that are too loose can create risks and discomfort through rubbing and movement. Aim for snug, not tight.
“It fit last month, so it should still fit”
Puppies and adolescents change shape quickly. Even adult dogs can change with coat growth, weight shifts, or seasonal coat changes. A quick check once a week is a great habit.
“My dog slips collars all the time”
That is not rare. It usually means the dog’s head/neck shape makes a flat collar unreliable, or the collar is routinely too loose. In those cases, a better-fitting collar style or a harness may be safer. If you’re unsure, ask us and we can help guide you.
When to get help
If you’re not confident your dog’s collar is right, you’re not alone. It’s one of those small details that’s easy to miss, and it’s also easy to fix.
Bring it up with us at training, or send through a quick photo of your dog wearing the collar from the side and front. A 30-second check can prevent a lot of stress later.
Final thought
Collars are not “set and forget”. A quick fit check takes seconds and can prevent:
- a dog slipping out and running off
- a scary catch-and-panic moment
- rubbing and irritation
- long-term sensitivity around collar handling
Simple, sensible, and worth doing.
Disclaimer: The information provided in this blog is intended as general guidance only and is based on our experience as dog trainers and behaviourists. It is not veterinary advice and should not be used to diagnose, treat, or manage medical conditions, and it should not replace consultation with a qualified veterinarian. Every dog is different, and any training or management ideas should be applied with your dog’s individual needs in mind. If you have any concerns about your dog’s health, wellbeing, mobility, behaviour, or safety, we recommend speaking with your vet to ensure the best care for your dog. If you believe your dog may be unwell, injured, in pain, or you suspect an urgent issue (for example, difficulty breathing, collapse, seizures, or a bloated abdomen), seek veterinary help immediately.
