A system for delivering molecular iodine or other substance into a pet's drinking water on a daily basis without exceeding the safe amount allowed for the pet. The system 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. Each enrolled pet is electronically recognized by the system.
