The Hill's® pet food lines began in 1939. Dr. Mark L. Morris Sr. believed certain health conditions in pets could be managed through carefully formulated nutrition. His ideas were visionary in veterinary medicine, and he soon had the chance to prove his theory.
A young blind man named Morris Frank asked Dr. Morris if anything could be done to help his guide dog, Buddy, who was having kidney health issues. The result of Dr. Morris' efforts was the nutritional formulation that became the first product in the Hill's Prescription Diet line of therapeutic pet foods, and the world's first pet food designed for kidney health.

Soon after, Hill's Pet Nutrition was founded and the field of clinical nutrition sprang to life. That first therapeutic dog food evolved into Hill's® Prescription Diet® k/d®, which is still sold today.