No, you should not. Capstar is an oral medication designed to be swallowed whole by your dog. It should not be mixed with water or other liquids before administration, which can affect the medication's effectiveness. Capstar tablets are designed to dissolve quickly in your dog's mouth and are flavored to make them more palatable. If your dog has difficulty swallowing the tablet, you can try hiding it in food or administering it directly into the back of the throat.