Final answer:
In a dog diagnosed with diabetes mellitus, ketones would be expected in the urine due to the body using fats instead of glucose for energy, indicating the presence of diabetic ketoacidosis.
Step-by-step explanation:
If a dog is diagnosed with diabetes mellitus, you would expect to find ketones in the urine sample. In diabetes mellitus, due to insufficient insulin or insulin resistance, glucose cannot be effectively utilized by the body's cells for energy.
As a result, the body turns to metabolize fats for energy, which leads to the production of ketones. Ketones are byproducts of fat metabolism and their presence in urine, a condition known as ketonuria, is indicative of the body using fats rather than glucose for energy.
The excess production of ketones can lead to a condition known as diabetic ketoacidosis, which is potentially life-threatening and requires prompt medical attention.