If blood tests and urinalysis came back normal, I would be more inclined to look for Cushing’s Disease especially if there are other symptoms which are typical for Cushing’s Disease like a pot belly or symmetrical hair loss; an ultrasound may be unrewarding but may shed some light on other issues within the abdomen. Increased thirst and urination may be caused by many different conditions including other hormonal conditions, infections, age, spinal disorders (more the incontinence) or dietary changes. Regards Dr Callum Turner DVM
Calcium supplements often come in chewable (., chocolate-flavored) or tablet formulation in human medicine, and are readily found in households. When dogs ingest these supplements in large amounts, it can result in electrolyte changes (., transiently elevated calcium blood levels) or even chocolate poisoning in dogs. (Cats, by the way, generally do not ingest enough of these supplements to result in poisoning due to their discriminating palate.) Calcium supplements often also contain large amounts of Vitamin D3 and Vitamin K, which can also result in toxicity. While calcium is generally poorly absorbed from the gastrointestinal tract, the addition of Vitamin D3 increases the risk of toxicity.