Hi, I'm Dr Steve.
Itchy feet can be a sign of irritation and the licking helps to soothe irritation. This can be from a plant awn or seed being stuck in the foot or if can be from a cut or scratch that is causing problems. THis typically involves only one foot so if more than 1 foot is causing problems then this may not be the issue. I carefully examine the involved feet for signs of a foreign body stuck in the foot or the pad and for scratches , cuts or tears in the pad.
Another common cause of itchy feet is allergies. Dogs become very itchy with allergies and typically lick their feet. IF you don't see anything wrong with the feet, allergies could be a possibility. Dogs can be allergic t the same things that people are allergic to and this is the allergy season. I have had clients soak the feet in an oatmeal bath to help soothe the feet and also give 1 mg per pound of Benadryl orally once to twice a day for 2 days to see if that helps. If he has allergies, then it is also possible that he may have a secondary skin infection from the licking. When he licks it keeps the skin moist in that area and that can cause a skin infection.
You may need to take him to a vet to determine if he has a skin infection. Also if the Benadryl doesn't help, then he may just have a skin infection that is causing irritation and no allergies and he may need antibiotics. Your vet should be able to determine if this is the case. If you have tried the Benadryl and have had no response , then again it may not be allergies or it may be that he has severe allergies that may require an allergy shot or steroids to help relieve the symptoms.
As for him having a fever, usually when a dog has a fever they will refuse to eat because they just feel so poorly that they don't want to eat. I have had clients check a dog's temperature by using a human rectal digital thermometer and gently inserting it into the rectum after putting a drop of soap on the tip for lubrication. THe normal temperature is 101-102 F and I it s higher than this, he does have a fever and should be seen by a vet.
I hope this has helped. If you have more questions, please let me know I will check later this evening ( US time) to see if you have more questions. THis question will remain accessible even after you have rated my answer so we can continue this dialogue until you have all your questions answered. THanks for the question and good luck.