Zoopharmacognosy is a big and tricky word that means animals using plants and other things to make themselves feel better when they have a health problem. Just like how you might eat chicken soup when you have a cold, some animals use different plants, fruits or even clays to help with different problems they might have!
For example, some monkeys have been seen eating specific leaves that help get rid of parasites in their stomachs. Or some parrots and macaws like to eat specific kinds of clay to help them with digestion or toxin removal.
It's kind of like animals having their own health system, where they know which foods will help with which problems. And it's all completely natural and instinctive - they just know! Cool, right?