Check the fit weekly, not monthly
This is the single most important thing on the page. Puppies grow fast enough that a collar which passed the two-finger check on Sunday can be tight the following Sunday, and a collar that is left to grow into the neck is a genuine injury.
Pick a day and make it a habit. Two fingers flat under the collar, at the base of the neck. If you can only get one finger in, loosen it or replace it — and if it is on the last hole, it is finished regardless of how new it looks.
Buy for the adjustment range, not the size label
Size labels are a manufacturer’s opinion; the adjustment range is a number. A collar that spans 8–12 in gives you four inches of growth; one that spans 10–12 in gives you two, and will be outgrown twice as fast.
Look for the range printed in the listing and buy the widest one your puppy’s current neck sits comfortably inside — ideally near the lower end, so most of the range is still ahead of you.
The collar is for the tag; the harness is for the leash
Puppies pull, and they pull with no technique whatsoever. A collar concentrates that on the throat of an animal whose trachea is still developing, and the AKC’s harness-versus-collar guidance favors a harness for any dog that pulls.
Put the collar on for identification and put the leash on a properly fitted puppy harness. Our puppy harness roundup picks on adjustment range for the same reason this page does.
Introduce it before you need it
A puppy that meets a collar for the first time on the day of the first walk has two new experiences at once, and it will remember the wrong one. Put the collar on for a few minutes indoors, with something good happening, and take it off before the puppy starts working at it.
Build from there. Most puppies stop noticing a collar within a few days if it is introduced this way, and stay suspicious of it for months if it is introduced by being held down and buckled.
Get the ID tag on it from day one
The riskiest weeks of a dog’s life for going missing are the first ones in a new home, when it does not yet know where home is or that you are worth coming back to. A tag is a few dollars and it works without a phone, a signal, or a scanner.
Put a phone number on it — not the dog’s name, which mostly helps somebody call your dog away from you. A microchip is the permanent backup and should be registered rather than merely implanted, but a chip only works if the finder takes the dog to someone with a scanner. A tag works immediately. Our ID tag roundup covers what to engrave.
Never leave a collar on an unsupervised crated puppy
A hanging tag or a loose collar can catch on wire crate bars, and a puppy that panics against a snagged collar is in real trouble very quickly. Take the collar off for crate time, or use a slide-on tag with a well-fitted collar if you would rather it stayed on.
The same applies to unsupervised play with another dog — jaw-through-collar accidents are rare but severe, and both problems disappear if the collar comes off when nobody is watching.
Skin: puppies react to things adults do not
A puppy’s skin is thinner and its coat has not come in properly, so a stiff webbing edge that an adult would ignore can leave a red band. Neoprene padding solves this cheaply, and the padded collars cost a dollar or two more than plain nylon.
If the collar is coming off wet from puppy-pad accidents or drinking, dry it rather than leaving it on — a permanently damp collar against soft skin is the usual cause of the rash people blame on the material. Our sensitive-skin collar guide covers the material choices properly.
