Good Morning and welcome! I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
From what you have told me, it appears that your sweet Dessie is suffering from an allergic reaction that could be due to many things such as fleas, pollen , foods.
For now , follow these instructions:
Apply Betadine to the areas that appear red or irritated every 8 hrs. Clip away all the hair in this area. This is a skin infection called a pyoderma caused by the irritation. This will dry out the area so the bacyeria cannot grow. These can both be purchased at the pharmacy over the counter.
Give Benadryl at 1 mg per pound every 12 hrs for 10 days.
Bath weekly with Malaseb or Dermaplex which will remove the scabs or flakes. This can be purchased at the pet store or online.
If there is no response, then your vet will have to run tests such as skin scrapings and cultures to determine the cause and then they will treat according to these results.
Dessie's behavior and weight loss is associated with the irritation...once you remove the irritation, this will resolve. Make sure you are usinga good flea control since it only takes one flea to cause her to break out like this.
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, ***** *****