194 ANATOMY AND DISEASES OF THE 



CHAPTER XII. 



ANATOMY OF THE GULLET, STOMACH, AND INTESTINES I TETANUS; 

 ENTERITIS ; PERITONITIS ; COLIC ; CALCULUS IN THE INTES- 

 TINES ; INTUSSUSCEPTION ; DIARRHOEA ; DYSENTERY ; COSTIVE- 

 NESS ; DROPSY ; THE LIVER ; JAUNDICE ; THE SPLEEN AND 

 PANCREAS ; INFLAMMATION OF THE KIDNEY ; CALCULUS ; IN- 

 FLAMMATION OF THE BLADDER; RUPTURE OF THE BLADDER; 



WORMS ; FISTULA IN THE ANUS. 



THE oesophagus, or gullet, of the dog 1 , is constructed in nearly the same 

 manner as that of the horse. It consists of a similar muscular tube 

 passing down the neck and through the chest, and terminating in the 

 stomach, in which the process of digestion is commenced. The orifice by 

 which the gullet enters the stomach is termed the cardia, probably on 

 account of its neighbourhood to the heart or its sympathy with it. It is 

 constantly closed, except when the food is passing through it into the 

 stomach. 



The stomach has three coats : the outermost, which is the common 

 covering of all the intestines, called the peritoneum ; the second or mus- 

 cular coat, consisting of two layers of fibres, by which a constant motion 

 is communicated to the stomach, mingling the food, and preparing it for 

 digestion ; and the mucous or villous, where the work of digestion properly 

 commences, the mouths of numerous little vessels opening upon it, which 

 exude the gastric juice, to mix with the food already softened, and to con- 

 vert it into a fluid called the chyme. It is a simpler apparatus than in the 

 horse or in cattle. It is occasionally the primary seat of inflammation ; 

 and it almost invariably sympathises with the affections of the other in- 

 testines. 



The successive contractions of each portion of the stomach, expose by 

 turns every portion of the alimentary mass to the influence of the gastric 

 juice, and each is gradually discharged into the alimentary canal. 



As the chyme is formed, it passes out of the other orifice of the stomach, 

 and enters the first intestine or duodenum. 



It may be naturally supposed that this process will occasionally be in- 

 terrupted by a variety of circumstances. Inflammation of the stomach of 

 the dog is very difficult to deal with. It is produced by numerous different 

 causes. _ There is great and long-continued sickness: even the most 

 harmless medicine is not retained on the stomach. The thirst is exces- 

 sive ; there are evident indications of excessive pain, expressed by the 

 countenance and by groans : there is a singular disposition in the animal 

 to hide himself from all observation ; an indication that should never be 

 neglected, nor the frequent change from heat to cold, and from cold to 

 heat. 



The mode of treatment is simple, although too often inefficient. The 



