Oral Anatomy and Physiology in the Companion Animal

Part of the Advances in Delivery Science and Technology book series (ADST)


This chapter provides a synopsis of the anatomy and physiology of the gastrointestinal tract of small animals, specifically cats and dogs. The stomach is both a grinding organ and a reservoir, metering foodstuffs into the small intestine for further processing and absorption. The small intestine is the primary site of absorption. On the one hand, the gastrointestinal tracts’ acidified stomach contents may result in the precipitation of pharmaceuticals. On the other hand, in response to food, the secretion of pancreatic fluid, bile salts and lecithin in the small intestine may result in a fine emulsion that facilitates the aqueous solubility and subsequent absorption of the pharmaceutical ingredient (API). The large intestine (cecum and colon) completes the processing and absorption of nutrients. Absorption of the API in this region is balanced by its solubility and residence time in this organ. This chapter shows that there appear to be many similarities in the anatomy and physiology of mammals.


Gastric Emptying Colon Transit Intestinal Length Small Intestinal Transit Daily Energy Requirement 
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© Controlled Release Society 2013

Authors and Affiliations

  1. 1.College of Pharmacy, University of New EnglandPortlandUSA

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