to a very decided degree, even in individual animals belonging to the 

 same herd. 



At the beginning of an outbreak in a herd we usually observe only 

 one or two animals showing evidence of sickness. There is nothing 

 particularly characteristic in the signs of sickness displayed and the 

 presence of so grave a disease as cholera may not be suspected until 

 a week or two later when other hogs in the herd become sick. Of 

 course as the number of sick hogs increase there is an increase in the 

 amount and virulence of the infection, hence increased opportunities 

 are offered for the well animals to contract the disease. 



Acute Form. — This is by far the most common type met with in 

 field work. At the beginning the temperature is elevated from two to 

 four degrees or even as high as six degrees. Since the normal tem- 

 perature of a hog is 102 to 103 degrees, this would mean that in chol- 

 era cases the temperature would be 104 to 108 degrees. The tempera- 

 ture of a hog may be taken per rectum with a pear-shaped bulb ther- 

 mometer, and above 104 degrees in cholera-infected herds would indi- 

 cate sickness from cholera. On account of the high temperature, loss 

 of appetite, lassitude and marked depression are among the first symp- 

 toms presented. Vomiting is frequent. Usually the hog strolls off from 

 the remainder of the herd, selects a quiet place and lies down, some- 

 times hides by covering itself with litter such as leaves, straw, etc. The 

 inflammation of the intestines and soreness in the abdominal walls 

 causes arching of the back, tucking up in flanks, stiffness in hind 

 quarters and loins, often causing a crossing of the hind legs when the 

 animal moves about. When handled the pig has a peculiar squeal 

 and very little strength or power of resistance and is easily exhausted 

 and depressed. 



There is a muco-purulent secretion from eyelids which causes them 

 to adhere together. Reddish blotches or spots oftentimes appear in 

 the skin behind the ears, under the abdomen and neck. These skin 

 lesion- are particularly noticeable in hogs with light-colored skin. Con- 

 Stipation alternates with diarrhea. The color of the feces depends 

 upon the character of food which the hog has eaten. Thumps is a 

 frequenl symptom, so is quickened breathing and cough. As the dis- 

 ease progresses the symptoms become more well marked by the hog 

 becoming extremely weak and depressed and finally coma and death. 

 The lo ses from acute cholera will vary from 50 to j^ per cent. I Iow- 

 ever, those which survive an acute attack will go into the subacute 

 and sometimes the chronic forms. 



Subacute Form, Tin- i- the form 1h.1t the disease assumes after 





