Apple Photos is tagging my pets incorrectly in People & Pets and I can't remove the tags

I have had four black cats over the years, and they all look basically identical in photos. After I reviewed a bunch of photos and manually tagged the cats correctly, Apple Photos has proceeded to tag additional photos incorrectly, mixing up the names of the cats. I can't figure out how to remove or correct the auto-tags in People & Pets; selecting View > Show Faces does not bring up the tags or name labels. How can I correct the tagging on these photos?