24 DISEASES OF THE DIGESTIVE APPARATUS 



the stomach may not be digesting all that the animal eats, but still the 

 animal be in fairly good health; while, of course, it must also be under- 

 stood that in fevers or any general disturbance, the digestive powers are 

 greatly impaired. 



Albumin is almost entirely digested in the intestines, the stomach 

 merely preparing it; fat and starch are digested only in the small intes- 

 tines; muscular tissue must have a previous preparation in the stomach, 

 or, if it reaches the small intestines without becoming saturated with 

 gastric juice, it is not digested in the intestines. No digestion whatever 

 takes place in the large intestines. 



No animal vomits more easily than the dog, and it may be produced 

 from a number of causes, as a reflex irritation of the stomach, viz., 



1. By irritation of the mucous membranes of that organ by emet- 

 ics, posions, splinters of bone, or even by overloading. Vomiting 

 frequently is caused by the animal eating grass. 



2. By sympathetic irritation from other organs, intestinal parasites, 

 uraemia, peritonitis, irritation of the intestines, or uterine inflammations. 



3. Vomiting may result from serious coughing spells, as a result of 

 laryngitis, l^ronchitis, or liquids getting into the larynx. 



4. In obstruction of the bowels, foreign bodies blocking up the bowel, 

 hernia or twisting of the intestines. In some cases of the latter con- 

 dition excrement is vomited. 



5. In the early stages of distemper and infectious hemorrhagic gas- 

 tro-enteritis, persistent vomiting is almost invariably present. 



6. From various brain-affections (meningitis, commotio cerebri). 

 Very often in certain diseases of the pharynx and where foreign bodies 

 have become imljedded or fixed about the root of the tongue, pharynx 

 or oesophagus and in pharyngitis, movements of the throat resembling- 

 vomiting are frequently noticed. 



The amount of vomited matter depends to a certain extent on the 

 density of the material in the stomach, what it is composed of, and the 

 cfuantity present in the stomach at the time of the vomiting. In cases 

 where the animal vomits, when the stomach is full, the vomited material 

 will either be the food in a uniform pulpy mass, or the mass may be 

 largely fluid, with the food lying in it, with little alteration from when 

 it was swallowed. It depends largely on how long it has been in the 

 stomach and whether the stomach has digested it. When an animal 

 vomits when the stomach is empty, there generally is a small quantity 

 of water mixed with the mucus; the color varies greatly according to 

 the circumstances, white, yellowish-gray, yellow or yellowish-green; 

 this latter condition depends on staining from bile pigment. Other 

 colors may also appear. It may be gi'cen from eating grass; violet as 

 a result of licking a wound or eruption that has been treated with pyok- 



