Keratin is a type of protein found on epithelial cells, which line the inside and outside surfaces of the body. Keratins help form the tissues of the hair, nails and the outer layer of the skin. They are also found on cells in the lining of organs, glands, and other parts of the body.

Kibble is a form pet food that contains varying formula recipes of meats, grains, and vegetables that are dried and reshaped into small pellet-sized pieces.

The kidneys remove waste and extra water from the blood (as urine) and help keep chemicals such as sodium, potassium, and calcium balanced in the body. They also make hormones that help control blood pressure and stimulate bone marrow to make red blood cells. Also called renal function.