OK HE IS FOUR YEARS OLD... SO MAYBE HE IS NOT USED TO USING A LITTER BOX. WHY WAS HE IN A SHELTER.?????? YOU SHOULD CONFINE HIM TO A SMALL AREA IN THE HOUSE AND HE WILL USE HIS LITTER TRAY... ONLY DO THIS FOR A FEW DAYS AND I AM SURE YOU WILL WIN. HE NEEDS TO KNOW THAT THIS IS WHERE HE SHOULD DO HIS BUSINESS. ALWAYS WORKS FOR ME. IF HE WAS USED TO GO OUT SIDE HE WILL AUTOMATICALLY LOOK FOR SOME WHERE SOFT TO WEE.TRY PUTTING SOFT PAPER IN THE TRAY WITH A LITTLE LITTER IN IT.