Chapter 2

Apuntes

Chapter 2 Characteristics of the Digestive Tract of Dogs and Cats Wenliang He, Erin D. Connolly, and Guoyao Wu Abstract As for other mammals, the digestive system of dogs (facultative carni- vores) and cats (obligate carnivores) includes the mouth, teeth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, and accessory digestive organs (salivary glands, pancreas, liver, and gallbladder). These carnivores have a relatively shorter digestive tract but longer canine teeth, a tighter digitation of molars, and a greater stomach volume than omnivorous mammals such as humans and pigs. Both dogs and cats have no detectable or a very low activity of salivary α -amylase but dogs, unlike cats, possess a relatively high activity of pancreatic α -amylase. Thus, cats select low-starch foods but dogs can consume high-starch diets. In contrast to many mammals, the vitamin B 12 (cobalamin)-binding intrinsic factor for the digestion and absorption of vitamin B 12 is produced in: (a) dogs primarily by pancreatic ductal cells and to a lesser extent the gastric mucosa; and (b) cats exclusively by the pancreatic tissue. Amino acids (glutamate, glutamine, and aspartate) are the ...