What does it mean when your dog has cold paws?

Normally dogs have paws that are cooler to the touch than the body because they have a special system of blood vessels in their legs and paws to conserve body heat. This is called a "counter-current exchange" network and it works by having arteries and veins traveling next to each other. Heat is siphoned from the arterial blood to the venous blood, conserving body heat in the core tissues. This causes the paws to be cooler than the rest of the body, which reduces the amount of heat lost to the environment such as snow or mud when the dog walks around.

However, the paws shouldn't feel "ice cold" - just cool. An ice cold paw, particularly one that is noticeably cooler than the other paws, can indicate a blocked artery or other problems in the leg that need medical attention soon.