FEEDING THE DOG 



and the two together constitute the gas- 

 tric juice, which breaks down the proteid 

 constituents of food into more soluble 

 peptones. 

 MANY TWININGS AND CHURNINGS 

 The stomach turns and revolves upon 

 itself until the food is in a semi-fluid form 

 called chjmie. Then it (passes thru the 

 pylorus into the small intestine. 



SPLEEN ATTACHED TO STOMACH 

 The spleen is found on the outside left 

 of the stomach- 

 On the right side are located the right 

 lobe of the liver and the intestines. The 

 exit to the stomach is the pylorus. 

 THREE SECTIONS OF SMALL 

 INTESTINE 

 The small intestine has an average 

 length of about thirteen feet (about five 

 times the length of the body) and is di- 

 vided into three parts — duodenum, je- 

 junum and ileum. 



The intestines hang from the backbone 

 supported by a thin transparent mem- 

 brane filled with many small blood 



NECESSITY FOR "HEALTHFUL" 

 INTESTINE 



The intestines themselves are lined with 

 mucous and other secretory glands. The 

 inflammation of the membrane and glands 

 causes many ills of the dog such as 

 diarrhea and intestinal catarrh. Most 

 parasites are harbored in the small intes- 

 tine of the dog. 



THREE SECTIONS LARGE INTESTINE 



The large intestine, much shorter than 

 the small intestine, is about two feet in 

 length and is composed of caecum, colon 

 and rectum. 

 NO PERISTALIC OR WAVE MOTION 



Whereas the small intestine has both 

 longitudinal and crosswise bands of con- 

 struction in order to give the wavelike 

 contraction, there is no such construction 

 in the large intestine. 



THE DOG'S APPENDIX 



The caecum is about three to five inches 

 long and is found in the region of the 

 right flank. It is twisted in the form of 

 a spiral and corresponds to the appendix 

 in the human. It opens from the small 

 intestine thru the ileocaecal valve. Here 

 the whip worm and other parasites often 

 lodge, beyond direct contact with most 

 medicines. 



THE WINDING COLON 



The second part of the large intestine, 

 which also is called the bowel, is the 

 colon ; this is attached to the backbone 

 just back of the kidneys. It winds about, 

 touching the stomach on the right, then 

 backward to the left kidney. 



END OF ALIMENTARY CANAL 



The third part of the large intestine is 

 the rectum; this ends with the anus or 

 external opening thru which the contents 

 of the bowel are discharged. It is several 

 inches in length. 



B— INTESTINAL MOVEMENTS AND 

 FOOD CHANGES 



The piece of food which the eye sees, 

 is placed in the mouth and involuntarily 

 swallowed. It becomes a "part of the 

 eater" except that portion which is passed 

 out as unneeded thru the bowels. How a 

 piece of food eaten becomes life itself is 

 still a mystery that challenges the scien- 

 tists and their laboratories. 



The changes wrought by the digestive 

 process are chemical and mechanical. 



The mechanical factors in digestion are 

 intended mainly to aid in the chemical 

 changes. Consequently the mechanical 

 factors serve chiefly to break the food into 

 small particles and to move the particles 

 along the alimentary canal. 



The Dog Does Not "Spit" 



The first act, of course, is to place the 

 food into the mouth and chew it. Here 

 the teeth, tongue, membranes of the 

 mouth, and the saliva secretion do their 

 work. To this we must add the nerve of 

 taste, which is situated in the tongue and 

 also to some extent in the membranous 

 lining of the mouth. 



The saliva in humans, thru the enzyme 

 iptyalin, converts starch into sugar. Most 

 domestic animals do not have ptyalin in 

 the saliva ; the dog, cat and fox have little 

 or none at all. 



Consequently, the chewing of food by 

 the dog is not necessary for the purpose 

 of adding saliva. 



Three Chemical Factors 



The chemical factors comprise three 

 senez»I crroups. 



The first is enzymes, which are pro- 

 duced by the digestive glands and which 

 are present in the food itself. 



The second is bacteria and protozoa. 



The third is the chemical substances 

 other than enzymes which are (produced 

 in the digestive process, for instance 

 hydrochloric acid. 



Five Intestinal Objects 



The movement of the intestines may be 

 considered to have five purposes : 



1. to mix the food with the digestive 

 juices ; 2. to bring the food after broken 

 down into liquid form into contact with 

 the mucous membranes for absorption 

 into the blood stream; 3. to move the in- 

 gesta from place to place along the 

 bowel ; 4. to expel the residue or unwant- 

 ed material from the rectum thru the 

 anus or external opening ; 5. to assist in 

 the flow of blood and also of lymph thru 

 the vessels which are located in the wall 

 structure of the intestines. 



Action of Digestive Juices 



Saliva is somewhat alkaline. After it 

 has acted upon the food, altho very little 

 in the dog, the stomach produces the gas- 

 tric juice, an acid secretion. The enzsrme 

 pepsin is found in the gastric juice and 

 acts particularly on proteins. 



After the food has gone from the stom- 

 ach into the small intestines, the pan- 

 creatic juice, which contains three en- 

 zymes, trypsin, amylopsin, and stespin— 



