70 DISEASES OF CATTLE. 



which enter into the composition of hay, bluegrass is the most likely 

 to become affected. Ergot may also affect redtop, oats, grasses, 

 and grains. On the plant the fungus manifests itself on the seeds, 

 where it is easily recognized when the hay is examined in the mow. 

 The ergotized seeds are several times larger than the natural seeds — 

 hard, black, and generally curved in shape. 



The effect of the protracted use of ergot in the feed is pretty well 

 imderstood to be that of producing a degeneration and obstruction 

 of the smaller arterial branches. The result is to shut off the blood 

 supply to the distal parts of the body, where the circulation is weak- 

 est, and thus to produce a mummification or dry gangrene of the 

 extremities, as the ears, tail, feet, etc. Cattle seem to be more suscep- 

 tible than other animals to the influence of ergot, possibly on account 

 of the slowness of the heart's action. When the effect of the poison 

 has become sufficient to entirely arrest the circulation in any part, the 

 structures soon die. The disorder manifests itself as lameness in one 

 or more limbs; swelling about the ankle which may result in only 

 a small slough or the loss of a toe, but it may circumscribe the limb 

 at any point below the knee or hock by an indented ring, below 

 which the tissues become dead. The indentation soon changes to a 

 crack, which extends completely around the limb, forming the line 

 of separation between the dead and living structures. The crack 

 deepens till the parts below drop off without loss of blood, and fre- 

 quently with very little pus. Ergot may cause serious irritation of 

 the digestive tract,- or by acting upon the nervous system it may 

 cause lethargy or paralysis. It also operates to cause contraction of 

 the uterus, and may thus cause abortion. 



Treatment. — Eegarding the treatment, change of feed and local 

 antiseptics are, of course, indicated. The former may be useful as a 

 preventive, but when the symptoms have appeared the animal is nec- 

 essarily so completely saturated that recovery is likely to be tedious. 

 Tannin ma> be given internally in doses of one-half dram twice 

 daily for a few days to neutralize the unabsorbed alkaloids of the 

 ergot. At the same time give castor oil. To dilate the blood vessels 

 give chloral hydrate. Bathe the affected parts with hot water. If 

 sloughing has gone far, amputation must be resorted to. 



OTHER POISONOUS FUNGI. 



Many other fungi poison herbivora. In some instances, however, 

 where fungi are blamed for causing disease their presence on the 

 feedstuff or herbage is but coincidental with some other and more 

 potent disease-producing factor. For example, if the conditions are 

 favorable to the growth of fungi they are also favorable to the 

 growth of bacteria, and bacteria may produce poisons in feeds. In 

 general it may be said that any feed that is moldy, musty, or putrid 



