This is the what i did for my tiny baby monkey daily ,Taking care of a baby monkey with diaper rash requires gentle care and attention. First, clean the affected area with lukewarm water and a soft cloth, avoiding any harsh soaps. Pat the area dry gently with a soft towel. Apply a thin layer of a diaper rash cream containing zinc oxide to soothe and protect the skin. Ensure the diaper is loose enough to allow air circulation and change it frequently to keep the area dry. Let the baby monkey spend some time without a diaper to allow the skin to breathe. Monitor the rash, and if it doesn’t improve, consult a veterinarian.