A dog that licks its paws a lot may have allergic skin disease, an infection, parasites, a foreign object or irritation between the toes. Sometimes a dog licks a paw because it hurts further up the leg. Moisture and prolonged licking can in turn damage the skin barrier and cause secondary inflammation.
Look between the toes and around the pads and claws without digging into a tender area. Are several paws affected, does the problem come back at certain times of year, or are there ear problems and itching on other parts of the body at the same time? Patterns like these can help the vet understand whether it is a local problem or a more general skin disease.
Book an assessment if the paw is red, swollen, weeping or smells, if your dog licks intensely or if it is also limping. A sudden problem in a single paw may need to be examined for a wound, claw damage or a foreign body.