My Shih Tzu's tail hair is falling out. Is it an allergy or Cushing's?

You should have noticed an improvement from the Temaril P within a few days of use. I am not sure how old your pet is, but you have to consider other causes of alopecia now, which includes demodexx mite infestation, ringworm (if the skin is also red and has a crusty ring around it, or even an endocrine disorder (Cushing's disease causes a rat tail appearance). I would revisit the vet and get a skin scrape to look for mites, fungal culture (if indicated), and if those come up negative then bloodwork to look for endocrine disorders. Fish oils are not effective at treating alopecia in pets. They are only good for treating inflammation of the skin. Nor will they cause hair re-growth. We need to find out the underlying cause and treat that directly.

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.

Just based on the information you described, I would probably consider testing for Cushing’s disease first, but it is possible to have both conditions so I would do the additional thyroid testing at the same time or soon after. Good catch!

I agree that allergies are one of the most likely causes for your dog's scratching - this is a very common problem for many dogs in the summer. But there are other possible causes also that should be ruled out first - itching can also be caused by skin mites (mange), or bacterial or fungal infections. If the itching is allergy related, you can try bathing in a dog shampoo with either cortisone or aloe and oatmeal to help soothe the itching. But most allergy problems in dogs require prescription medications to treat successfully, so I would recommend having your dog examined by a vet if bathing her isn't helpful.

The most common cause for hair loss and itching in this particular area is flea allergies. I would recommend that you have Shi Shi examined by a vet. The vet will examine all of her skin and discuss her medical history. The vet may need to take a sample of the skin for examination under the microscope. Once they have a better idea as to the cause, as in fleas or flea allergies, mites, or bacterial infection, they can recommend an appropriate treatment plan. https://www.petcoach.co/article/flea-allergy-dermatitis-or-flea-bite-hypersensitivity/

Some common symptoms of Cushings's are panting, increased thirst/urination, but these are also common symptoms of many diseases. Bloodwork and endocrine testing can help to ferret that out. Neurologic symptoms can sometimes be present with Cushing's if there is a larger tumor in the pituitary gland but seizures can also be caused by other things as well so an MRI is typically required. CT can sometimes be used if a pituitary mass is strongly suspected. Itchy feet is typically caused by allergies which may also be associated with secondary infection. Next steps are to see your vet for an exam, bloodwork, and endocrine testing. Abdominal ultrasound and blood pressure measurement are also typical next steps. I hope this helps and thank you for using Petco Pet Education Center, formerly Petcoach!

The symptoms you are describing can be associated with Cushing's disease. I recommend you get Joe Pesci to a vet for an exam. In the meantime, you can try bathing him with a medicated shampoo like this one. The black skin you are describing sounds like a yeast infection on the skin. That could also be making him itchy. https://www.walmart.com/ip/Veterinary-Formula-Clinical-Care-Medicated-Shampoo-for-Dogs-Cats-Antiseptic-Antifungal-16-0-FL-OZ/24893142 Lather the shampoo on, wait 10 minutes and then rinse thoroughly. You can do this 2-3 times per week until the skin/hair is looking better. It is still best to get him to the vet for an exam as soon as you can. Skin issues/allergies are usually secondary to another underlying health issue. I hope this helps. Best wishes!