Hi this is Dr J and I will try and help you today.Give me some time to formulate an answer.
so, there are three main reasons why a dog would chew the way you are describing especially a Corgi. Either fleas as you mentioned, which by the way if Franklin is allergic to a flea bite then he will only need one bite from a flea to start going crazy with itching.The other possibility is that he has developed a food allergy.The last possibility is that he has developed an allergy to environmental components.If you have seen fleas in the past then there is a good chance that he has developed a flea allergy. For this, I would recommend that you buy an oatmeal based shampoo that is hypoallergenic from a pet store and bathe him with this in cool water. Not cold, but not warm either as warm water will aggravate the skin further. Then I would apply Frontline Plus every 2 weeks for 3 treatments, then go to every 28 days for life. Also to help with the itching, you can give benedryl for awhile to calm this down. Just so you know, regular flea shampoos are very irritating to the skin as is tea tree oil.Dogs do not tolerate either very well as they have very sensitive skin compared to people. He can have a mg per pound of body weight of benedryl twice daily. For example if he weighs 25 pounds then he can have 25mg of benedryl twice daily until his itching calms down. If all of this does not work for you, then a vet visit will be in order as he may need some steroids to get this calmed down enough.Please let me know if you have any questions about anything I have written as I want you to understand all of it very clearly and I want you to feel satisfied with my service.I will check back later to see if you have posted any questions for me. Sincerely, DRJ