My overweight dog is losing hair and acts like his side hurts.

Hi, I'm Dr. Johnson. I think I just answered a question about Aysha! The tail tip doesn't worry me, a lot of dogs get the hairless area. My own dog has it. The other picture of the moth eaten appearance to her fur is not normal. A lot of skin conditions looks the same unfortunately. The hair loss could be form a skin infection (bacteria or yeast), from demodex (a non contagious mite) or ring worm. Also I know we were discussing her being over weight and a low thyroid. A low thyroid can predispose dogs to skin infections. Also food allergies can also. I think you have a few reasons to see your Vet now! Good luck!

Allergies should not cause a dog to lose weight. He should be examined by a vet for a workup. Your vet can run bloodwork to look for kidney disease, liver disease, endocrine diseases, cancer, etc. Please call your vet to schedule an appointment and work-up. Your vet could also prescribe an anti-histamine to control his allergies.

From the description provided, your pet may be suffering from allergies secondary to fleas, environmental allergens such as dust, pollen, grass, or even a protein source in his diet. In addition to the food trial, it is imperative to administer the flea prevention on time every month. Even one flea bite can set off a reaction that can ultimately lead to a secondary skin infection.

Cushing Disease, food allergies (it's too early to see results yet), skin mites, flea allergies and environmental allergies can all cause these symptoms. Make sure you are conducting a proper food trial. If Maddox does not respond to the food trial, discuss with your veterinarian next steps. Here are some links with good information" https://vcahospitals.com/know-your-pet/cushings-disease-in-dogs https://www.petcoach.co/article/allergy-testing-immunotherapy-in-dogs/ https://www.petcoach.co/article/food-allergies-and-food-intolerance/ I agree with your vet that a hydrolyzed diet is the best option. I hope this helps.

This is probably due to a severe allergy, although it could also be fleas or mites. First of all, in order to rule out skin parasites, you will need to treat Rose with a high quality flea treatment (e.g. advantage), then get her to the vet to perform a skin scrape - this might reveal an infection or a mite infestation. If all of those came back negative, the next step is to treat the allergy symptomatically and try discovering the cause of the allergy. Some medications can be given by the vet in order to repair the skin lesions (steroids and antibiotics). simultaneously you should start her on a prescription hypoallergenic diet for at least 2 months. Hopefully you will see some results after all this, if not you and your vet should consider putting her on a long term allergy treatment (Atopica or Apoquel).

With the weight loss as well as the skin condition I would recommend a blood test to rule out internal diseases such as liver disease as well as a skin scrape and possible biopsy in order to fully investigate the underlying cause and to guide the most appropriate treatment

I'd have to say that this doesn't really look like pemphigus to me at all, but regardless, it's not a diagnose that can be made just by looking at the lesions, they have to be biopsied. It's also quite rare, so I would want to rule out other problems, like mange, ringworm, fleas, and allergies. If she's losing weight she may have an internal problem, and blood work will help to figure out what that is.