Measure the dog, read the product
Use the manufacturer’s measuring instructions and check the fitted collar on the dog. Look at how it sits during ordinary movement. A size label such as large is not consistent across brands, and a puppy’s fit needs frequent reassessment.
Inspect the whole system
Check stitching, fasteners, attachment points and the identification tag. Replace damaged equipment rather than improvising repairs to a load-bearing part. Match the collar to its intended use and discuss handling equipment with a reward-based trainer.
Keep a simple comparison sheet
Record neck measurement, adjustment range, material, closure and return terms before ordering. Try a fit indoors in a secure space first. A piece of equipment should support safe management; it cannot substitute for training or make an unsuitable situation safe.