106 



SWINIO PUAC'l'ICK 



infrequently parasites occur in sufficient numl)ers to produce local 

 irritation of sufficient extent to result in catarrhal enteritis; finally, 

 acute catarrhal enteritis may be associated with a variety of infective 

 diseases. 



Lesions. — The lesions may be localized or they may be general, 

 involving practically the entire intestinal mucosa. In the begin- 

 ning the affected mucous membrane is red, tumefied, and rather 

 dry, but later it becomes coated with mucous which is produced in 

 excessive quantities as the disease progresses. Tlie submucosa may 

 be swollen, due to the accumulation of inflammatory exudate. The 

 tumefaction of the mucosa sometimes effectually closes the ducts of 

 the intestinal glands, thus forming retention cysts, and the villi are 

 turgescent and have a velvety appearance. The lymphoid tissue 



Pig. 24. The mud wallow Is a prolific source of infection. The hogs in 

 this wallow were affected with enteritis. The one in the center had tetanic 

 spasms. Note how it went down in the back. The pig at the right could 

 scarcely walk because of tetanic spasms. (Photo by Keehn.) 



usually becomes swollen and contains excessive quantities of leuko- 

 cytes which may be expressed as a milky substance. There may, in 

 the advanced stages, be areas of necrosis of the epithelium of the 

 mucous membrane. In the submucosa, hemorrhages of varying size 

 may occur. 



Symptoms. — Acute catarrhal enteritis occurs most frequently in 

 connection with acute catarrhal gastritis, and tlie symptoms of gas- 

 tritis usually overshadow those of enteritis. Inappetence or varia- 

 tion of appetite, rise of temperature, listlessness, and arched back 

 are common symptoms of acute gastrointestinal catarrh. The symp- 

 toms of acute intestinal catarrh are frequent defecation of small 

 quantities of mucous-coated feces. In the beginning, there is usuallj' 



