Have you had her examined by a vet lately? I've noticed that some older dogs become more vocal due to some cognitive decline as they age. I saw this with my older Corgi towards the end of her life. She didn't exactly have dementia but she was definitely more stressed out and barky about the daily activity in our home. That would be the first place to start figuring this out. I would hate to use a corrective collar on an older dog that may be showing some type of stress without investigating throughly.
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