DISEASES OF SHEEP 575 



Destroy the heads or brains of giddy sheep, and keep sheep dogs and 

 ranch dogs free of tapeworms. The first is the more important of 

 the two. 



Destroy the heads by burning, or split the skull, scoop out the 

 brains, chop them up or crush them, and cover with turpentine, 

 formaldehyde, or sheep dip. Ignorance and carelessness, resulting 

 in leaving heads of giddy sheep to be eaten by dogs or coyotes, are 

 responsible for the spread of gid in Montana. Instead of killing 

 giddy sheep and destroying the brain, the more favorable cases may 

 be operated on if desired, taking care to destroy the parasite when 

 it is removed from the brain. 



Tapeworm remedies should be administered to dogs at least 

 once a year when the outbreak of gid for the year is over. The med- 

 icines may be measured out in capsules in the amounts noted in the 

 text. The tapeworms should be destroyed by burning or burying 

 with quicklime or sheep dip. (Bu. An. Ind. Cir. 165, 1910.) 



THE BROAD TAPE-WORM (TAENIA EXPANSA) . 



This tape-worm is now one of the most common parasites of 

 sheep. It occurs wherever sheep are kept in this country. On ac- 

 count of its breadth and great length it is easily recognized. The 

 length may exceed five yards and at the broadest part it is from one- 

 half to three-fourths of an inch wide. At the head the width is not 

 so great. This parasite is found in the intestine at all seasons, but be- 

 comes numerous in the fall and early winter. The life history of the 

 worm is not clearly understood, but is thought to be quite simple. 

 On reaching maturity a number of segments are shed at one time and 

 the embryos contained in these segments, after reaching the herbage 

 or water, undergo certain changes, and entering the body of another 

 sheep, reach complete development, and again] produce embryo, 

 which are shed as before. As the conditions in spring and sum- 

 mer are very favorable for the existence of the embryo outside of the 

 body, sheep may become badly infected at this time, and show symp- 

 toms of tape-worm disease in late summer or fall. Low, wet pas- 

 tures are supposed to be most favorable for producing tape-worm 

 disease, but probably an overcrowded pasture, even if high arid 

 dry, is as much to be avoided. 



The best evidence of the presence of tape-worm is the finding 

 of the segments in the droppings. Unless a number of the para- 

 sites are present, no indication of disease will be observed, but when 

 present in considerable numbers in young lambs, serious trouble 

 often arises. Dr. Curtice mentions finding fourteen adult worms in 

 a lamb four months old, and that the number of individuals pres- 

 ent may be from two or three to a hundred. It is seldom, however, 

 that more than five or six are observed. Symptoms of disease do not 

 appear until the parasites reach considerable size, when they par- 

 tially block up the intestinal tube and probably cause considerable 

 irritation. The affected lamb ceases to thrive, becomes weak and 

 emaciated, and may finally die from exhaustion. In late stages, diar- 

 rhea is a prominent symptom. The mucous membranes are pale, 

 the wool becomes deprived of oil and is easily pulled out, and the 



