To find the right size for the jumper, you will need a measuring tape: measure the length of the dog’s back from the nape of the neck to the base of the tail, the neck circumference and the chest circumference, leaving about a centimetre of leeway. With these measurements, you can find the right size for your four-legged friend in a size chart from manufacturers like Trixie, from dog jumpers for French Bulldogs and similar small breeds to jumpers for large dogs.