Good Morning and welcome! I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
I am so sorry to hear about Theo's condition. This appears to be a form of Obsessive/Compulsive behavior so that once he starts chewing, he cannot stop. This may require an anti anxiety medication from your vet since this condition comes from this but for now, I would try giving Theo Benadryl at 10 mg every 12 hrs. This is an anti histamine that will make Theo drowsy and hopefully, stop the irritation that is cauisng him to continue to chew. You probably will have to keep the Elizabethan collar on for a few days.
If this is not enough, ask your vet for this anti anxiety medication such as Xanax...it can really help.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please REPLY so I can clarify for you.
Sincerely, XXXXX XXXXX
Thank you so much, Joy, for your kind rating. It is very much appreciated! Even though you have rated, we can still communicate. If you have other questions, please Reply. I am always happy to help. I hope Theo improves soon!
Have a wonderful day!