and with 24,000 creatures, the henry doorly zoo in omaha is always coping with sick animals. like rhea, a 6-year-old ring-tailed lemur with diabetes. she needs medication every single day and getting her to take it is no easy task. primates are very very good at picking out their medicine no matter what you put it in. they will pick that item out. and often spit them at you. reporter: combine that with the fact that hundreds of different animals need treatment from different drugs every day and you have another problem. finding the right dosage. obviously these human medications weren t designed for a 5 1/2 pound patient. reporter: that s when zoos turn to drug compounders, pharmacies that mix medications to fit a patient s need. they can find the right dosage of a human drug for rhea and make a bitter medicine taste like a treat. a request justin kohll fills every day. we have to figure out what they like and what they re eating. birds like fruit flavored. dogs like any kind