Make your dog feel loved, take it shopping! Don't thin a large dog collar would suit all dogs. That's totally a stereotype. It all comes back to the size of your dog's neck. Some dogs are built heavy all over, some are tiny but may have a thick neck, and some may be all tiny and bony. ..but remember there are dog collars for all sizes. Hence you can't just buy a large dog collar and expect it to suit your dog. If it doesn't you're not only going to lose your money incase the pet store doesn't refund the money, but you're going to create a big problem for your dog too.
You may be very choosy about the color, material or overall design of your dog's collar but just think out of the box. It isn't looks that matter always. It's the comfort, and just because a dog can't speak that doesn't mean you make a random purchase and put it onto your dog. Large dog collars for a small dog can make the dog run away as it would be easy to escape from the leash! Don't even rely on the size tags on the dog collar. Think practically and try the dog collar onto your dog right in the pet store.
So large dog collars or small..? Invest some time, patience and money and the answer is yours!