Why is my 10-year-old dog losing hair? Cushing's or Hypothyroidism?

Hello and thank you for reaching out to us concerning your pets hair loss. Yes, hypothyroidism can be a cause of an older dogs hair loss. The clinical signs of hypothyroidism are no itchy hair loss, panting, constantly seeking out vents or shady places because the heat bothers them, etc. but this condition usually begins between the ages of two and five but there are some situations in which happens at an older age. There are many other diseases that can also cause hair loss so it is in your best interest To take him to a veterinarian to have a full physical examination performed. The vet will be able to run tests such as blood work up, thyroid testing, skin scraping, etc. to be able to make a diagnosis and put him on the correct treatment. I hope this information has helped. Have a great day.

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!

Jax is very cute! In dogs HYPERthyroidism is very rare. However HYPOthyroidism is much more common and can certainly cause hair loss or unusual hair patterns. It would be a good idea to have Jax's thyroid levels checked. Cushing's disease can also cause hair loss so it may be a good idea to have him rechecked for Cushing's. Thanks for using Petco Pet Education Center, formerly Petcoach and best to you and Jax!

Hair loss and increased appetite are common causes of an endocrine disorder called Cushings disease. This is a common problem in older dogs and they usually are drinking more water then normal as well. I would highly encourage you to consider having Diamon evaluated by a veterinarian soon. They may recommend blood work to help determine the diagnosis. Best of luck and thank you for using Pet Coach.

Dogs that are hypothyroid have a deficiency of thyroid hormone which can cause the symptoms you describe as well as lethargy, weight gain, etc. Replacing with thyroid hormone is the only way to treat the problem, and it is necessary to confirm that she is indeed hypothyroid before starting treatment. Unfortunately there is nothing that can be given at home.

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.

There is a possibility that your dog is suffering from hypothyroidism, so your vet should also do a thyroid test. Hypothyroidism can also cause hair loss as you describe. Another possibility could be seasonal alopecia, also called cyclic follicular dysplasia which causes hair loss on the flanks and back, just as you describe. The treatment is melatonin. It will not be a remedy showing success within a few days, so the melatonin will have to be given over several months, if not life-long. In some dogs the hair will never grow back. Your vet may want to take a skin biopsy and send it in to a pathology lab. This can also give valuable information about the cause of the alopecia.