Cats have been my biggest problem during photo sessions. Crawling on my knees, following them around, laying on my tummy under a dining room table. The best was this one very uncooperative cat that the owner thought was human. He very calmly stood there saying to the cat "Sit still for the nice lady". Duh, the cat was not about to listen and the owner didn't seem to know that. The good news is that I outlasted the cat. I much rather paint real humans then animals that think they are.
Mary