SWINE FEVER—VERRUCOUS ENDOCARDITIS AND PNEUMONIA OF THE PIG.
Although it is not contemplated in this work to deal with those disorders which, on account of their highly contagious or infectious character, can only be dealt with by legislative action and by processes of “stamping-out,” it may be permissible to make certain exceptions. While we have made no reference to contagious pleuro-pneumonia of cattle, foot-and-mouth disease, rinderpest, anthrax and black-quarter we have devoted some space to Texas fever and tuberculosis, and give herewith a summary of the present state of knowledge regarding swine fever or hog cholera and a hæmorrhagic septicæmia of cattle known under various names in different countries and of very wide distribution.
SWINE FEVER.[[9]]
[9]. Report of the Departmental Committee re Swine Fever. (Annual Report of Board of Agriculture, 1896.)
Swine fever may assume two distinct forms, viz., the acute and fatal and the non-acute or slowly progressive.
Symptoms. In the acute form all those symptoms which are indicative of a severe febrile affection are present. The animals are disinclined to feed; they present evidence of great prostration and lie about their dwellings in a listless manner sheltering themselves from cold; their skins are hot, their eyes partially closed, and they are obviously suffering from some severe constitutional disturbance. Within a very few hours after these premonitory symptoms have set in the pigs become rapidly worse; they may or may not have a deep-red blush on the skin, which is more particularly noticeable on those parts of the body where there is an absence of hair, such as the inside of the thighs, the point of the axilla, and over the abdomen. Choleraic evacuations, having a most offensive odour, succeeding upon constipation, follow later on, and the animals die perhaps as early as the third or fourth day after the symptoms have first been observed.
In some instances the disease proceeds with great rapidity through a herd, the symptoms being of a most aggravated and pronounced character, and the outbreak attended with great fatality.
Generally speaking, the above description depicts the symptoms of swine fever in the acute form, more especially when it breaks out in a herd of young pigs.
In the non-acute form the disease progresses slowly, the clinical evidence is extremely obscure, the reddening of the skin, formerly regarded as being invariably present in swine fever, is absent, and beyond the fact that the animal is unthrifty, develops slowly, and perhaps has a constantly relaxed condition of the bowels, it may be asserted that there are no symptoms which could be regarded as absolutely indicative of swine fever, and nothing short of a post-mortem examination will enable even an expert to satisfy himself that the animal was affected with the disease.
As a general rule swine fever assumes this non-acute and slowly progressive form in pigs which have arrived at an age when their powers of resistance to disease are materially increased, i.e., in animals of eight or more months old; on post-mortem examination they are found to have been extensively diseased, more particularly in the large intestine, a portion of the digestive apparatus which does not appear to perform any very important function in connection with the nutrition of the animal, and so long as the stomach and small intestines remain healthy, pigs with a considerable amount of disease in the large intestine may still keep up their condition for a considerable time.