Have you tried changing Tyler to a better quality canned food? Maybe adding some warm water to it to make it a little soupy. Do you leave fresh water out for him at all times? Cats are notourious for not drinking enough water. It is imperitive cats get an adequate amount of water daily in order to have everything functioning properly.
Also, have you tried adding pure pumpkin to his diet? Not the pie filling. The pure pumpkin. It acts both as a laxative and for diarrhea. A tblsp mixed in with his canned food may help.
Assumptions do nothing but make an ass out of u and me.
We can stick our heads in the sand for only so long before it starts choking us. Face it folks. The pet population is bad ALL OVER THE WORLD!