Aloha! You're speaking with Dr. Michael SalkinI'm sorry to hear of this with Tia. At Tia's age the two main considerations we have for fecal incontinence are rectal/anal disease and a neurological disorder.Tia's vet needs to carefully examine Tia's anus and rectum for anal sphincter weakness and inflammatory changes suggestive of infection (anal gland impaction/abscessation, e.g.) or malignancy. This is usually done digitally but it might be a challenge to digitally examine such a small dog as she so sedation +/- scoping might be suggested. If anal sphincter tone is deemed to be weaker than normal, we should consider a neurological disorder. A myelopathy - spinal cord disorder - would be most likely. If Tia is demonstrating any other symptoms of a myelopathy - pain upon being lifted, a change in posture - "hunching", perhaps - or difficulty in jumping up or down or navigating steps - a myelopathy involving her lumber spine (a degenerating disk, e.g.) should be considered. This may or may be able to be confirmed on X-rays but that would be my first diagnostic if I were entertaiing the idea of a myelopathy.I'm sorry for the delay in replying to you. I just came online to find your question languishing on the question list. Please respond with further questions or concerns if you wish.