Hello, I'm sorry to hear about your fellow.
Excessive paw licking is generally due to an allergy or to arthritic/orthopedic pain of some type.Once the paws are excessively wet and raw it is a perfect environment for yeast to grow. And a yeast infection is itchy too so things are only compounded.
Soem dogs also excessively lick when they are nervous or stressed, but that tends to be at a single spot only.
To help with allergic symptoms you can use a combination of antihistamines and high doses of omega-3 fatty acids (they also help with the symptoms of flea allergy). In combination fatty acids and antihistamines work synergistically, much better than either one alone. If his symptoms worsen seasonally I would think that inhaled allergens are a part of his problem.
You can try 1)Benadryl (diphenhydramine only don't use the combo products as they can be toxic) at 1mg to 2mg per pound or one 25mg capsule per 25 pounds of dog orally every 8 hours. OR 2)Claritin (loratidine) at 5mg per 25 pound dog once or twice daily. OR 3)Hydroxyzine at 1mg per pound orally every 8 hours. OR 4) Chlorpheniramine at 4mg to 8mg per dog once or twice daily Some dogs do better on one antihistamine rather than another. You'll have to see which one works. Most dogs respond to Hydroxyzine the best. Give each a week to 10 day trial and if it isn't working try another. Be aware antihistamines can cause sleepiness or hyperactivity in some dogs. These side effects do wear off with repeated use.
Omega-3 fatty acids are fish oil products. 3V by DVM or Derm Caps ES are good brand name products. Use the high end of the dosing schedule for your pup's weight.
Cool water baths or rinses of the paws with an oatmeal shampoo or chlorhexiderm shampoo (which is antibacterial and antifungal) and a conditioner with an antihistamine. The water rinses off allergens and the cool temperature soothes itchy skin. Some people use wipes to remove allergens and if yeast is present then malsaeb wipes may be helpful. I do think the rinsing action is helpful too though as it removes allergens.Food allergy is possible. Dogs with food allergies tend to lick and scratch their paws, face and ears the most, but any of the "allergy reactive areas" can be affected. You could try a true hypoallergenic diet like Hills z/d or Purina Veterinary Diets HA.This must be the only thing he eats, no treats, flavored meds or bones while he is on his dietary trial. It may take between 8 to 16 weeks to see full effects.
If this isn't helping then the next step is radiographs of his front legs to look for orthopedic abnormalities (joint or bone abnormalities) that may be causing him to lick.
It appears that you are offline now.Please reply with questions if you have any after reading my response.