Your dog's paws are very sensitive.
I took my dog for a walk in the very heat of the day and ended up carrying dog home in my arms because she had developed huge blisters on her all four paws.
I took my dog home and soaked them in cool water and Epsom Salts. I then put a medication for burns on dog paws and wrapped them in gauss and vet wrap. I really felt sorry for her and mad at myself for not noticing that the pavement was way too hot for her dog feet.
Next to skin allergies, many owners of the many wonderful dogs have terrible problems with their dog licking and chewing on the feet, paws and nails. By now you might have caught on to many of the different causes of foot and dog paw pain.
Walk your dog on the grass or dirt. Yes, his feet will get dirty but I make it a habit to wash both of my dogs feet in the bathtub after a walk. They look forward to it because they don't have to spend a half hour licking their paws and feet to get the dirt and debris off the foot.
Another way to go is buy some boots for your dog. I've found them in dog shops but they seem to slip off a lot. These boots will help a great deal in the summer and in the snow.
Cracked paw pads are painful. You can apply some moisturizer to them if you see that they are very dry and appear to be cracking. Cracks in the paw pads if deep enough, can develop into an infection.
A foot licking problem can start out as a medical one and later become a habit to comfort oneself.
You should also take care of your dogs paws by trimming the nails every few weeks.