A system and method for delivering molecular iodine or any other substance into a pet's drinking water on a daily basis without exceeding the safe amount allowed for the pet. The present invention delivers a particular amount of molecular iodine into the pet water supply to achieve maximum benefit of I2 to reduce or eliminate bad pet breath and minimize total iodine in the pet diet so that 20-40 μg/mL/Kg/day iodine is consumed for optimum thyroid health. The preferred method is to use a solution created by dissolving iodine crystals in absolute ethanol. The iodine will only be in solution as I2 for a short time as it undergoes out gassing and hydrolysis at neutral pH. The present invention removes the iodine from the drinking water after the pet drinks. Therefore, during the day, pets will get no additional iodine—only fresh water from the water reservoir. Each enrolled pet is recognized by the system using an ID tag such as an RFID tag. This insures that, when there are multiple enrolled pets, each pet receives its specific dose, and only as often as is programmed. Vitamins, drugs and other substances can also be administered to pets using the present invention.
