Neck (where a collar would normally sit)
Chest (widest part behind the front legs)
Length (base of collar to base of tail)
For neck and chest, please allow sufficient room to slip two fingers between the measuring tape and the dogs neck or chest. A snug fit is what you are aiming for - just make sure it is not too tight.
For individual item size guides please refer to the relevant brand page.
To measure your dog we've also designed a tape measure that you can print at home.