530 HORSE, SWINE AND POULTRY DISEASES 



The curved tail has a conical shaped tip and is winged laterally. 



Method of Infection. The way in which hogs can become in- 

 fected has never been demonstrated. In all probabilities the eggs 

 pass out in the urine, and the embryo after developing for a time in 

 some moist place or in water, is taken into the body with the food 

 the same as in other parasitic forms. It is believed that no inter- 

 mediate host is required and the infection occurs direct. 



Symptoms. Hogs affected -by the kidney worm rarely show 

 symptoms of disease. In some cases diseased changes are noted in 

 the kidneys and in the fat around them ; sometimes the liver shows 

 a few lesions. In these cases the symptoms are the same as mani- 

 fested in diseases of these organs. This parasite seems to be of little 

 economic importance. 



Treatment. The preventive treatment indicated is the same as 

 for the intestinal forms. It is useless to try and treat them as they 

 are beyond the reach of any medicine, unless by such drugs as are 

 eliminated by way of the kidneys. (Ind. B. 100.) 



In many sections of the United States in which hogs are raised 

 one frequently hears farmers complain that their hogs are "af- 

 fected with kidney worms." Indeed, many farmers go so far as to 

 pronounce a positive diagnosis of kidney worm when they notice 

 that their animals are not in a good state of health. 



Because of the hog's habits, it is difficult to see any practical 

 measures which can be adopted to prevent infection. Feeding from 

 troughs and supplying plenty of pure drinking water will decrease 

 but not exclude the disease. Leuckart's advice to the Germans, 

 "Swine should be kept in a less swine-like manner," holds good in 

 all countries and in connection with all diseases. It is equally im- 

 possible to suggest practical methods of treatment. This is all the 

 more true because it seems probable that a number of distinct com- 

 plaints are popularly grouped together by the farmer as kidney 

 worm disease. (B. A. I. 153.) 



LUNG WORM, OR WHOOPING COUGH. 



The lung worm (Strongylus paradoxus, Mehlis) is a common 

 parasite in pigs under six months of age. It is found in the bron- 

 chial tubes. When the infection is slight the worms are found most- 

 ly toward the apex and margin of the lungs. In these cases the 

 lesions are not marked, and it is necessary to examine the lung very 

 carefully in order to detect them. In examining lung tissue for this 

 parasite, it is 'best to cut off the apex, and by squeezing it between 

 the fingers, force the lung worm out of the broncheole onto the cut 

 surface of the lungs, where they can be readily seen. It is the only 

 lung worm affecting hogs and may occur in sheep. 



Lesions. These are usually slight, and depend on the number 

 of lung worms present or the duration of the infection. The worms 

 are found in the bronchial tubes mixed with the mucus, and when 

 badly infected, the mucous membrane lining the smaller tubes be- 

 comes inflamed. As well as irritating the air tubes, it acts as a 

 mechanical obstruction by plugging up the smaller bronchi, and 

 causing a lobular pneumonia. The involved air cells usually re- 



