524 DISEASES OF CATTLE. 



tently. Hatching of the eggs may occur as earl}' as 10 days after 

 deposition. The larva? may live for 80 days without a host. The 

 parasitic period has been observed to vary from about two to about 

 seven months. 



Treatment. — On account of their protected location, ear ticks are 

 not likely to be affected by dipping or spraying. Ear ticks are very 

 difficult to kill, and remedies efficacious against them are liable to 

 injure the cattle. The parasites may sometimes be expelled by pour- 

 ing into the ear noninjurious substances, such as cottonseed oil, lin- 

 seed oil, 20 per cent emulsion of crude petroleum, or almost any 

 stock dip diluted as for use in dipping, but usually the results of 

 treatment are unsatisfactory. Some stock owners report favorable 

 results from arsenical dip (p. 496) poured into the ears. 



BLOODSUCKERS OR LEECHES. 



These worms are sometimes taken up by cattle when drinking from 

 ponds. They may attach themselves to the inner surface of the 

 mouth or nose, and sometimes reach the upper part of the windpipe 

 or of the gullet. Bleeding at the mouth or nose may be noticed, the 

 membranes where the leech is attached are liable to be swollen and 

 congested, and as a result of the loss of blood a condition of anemia 

 may result. 



Treatment. — If the worm can be reached it may be destroyed by 

 cutting it in two with a pair of scissors, or it may be removed with 

 forceps or with the fingers after wrapping a towel around the hand 

 so that the worm can be held without slipping. Fumigation with 

 tobacco or tar may cause the worm to release its hold if it can not be 

 removed by other means. Ponds may be rid of infestation with 

 bloodsuckers by the introduction of eels. 



PARASITES OF THE STOMACH. 



The stomach of cattle consists of four compartments, of which the 

 first and fourth are most likely to be the seat of parasitic infestation. 

 The first stomach, or paunch, contains large numbers of minute para- 

 sites known as protozoa, which are too small to be seen with the 

 naked eye. These small organisms aparently are m no way injuri- 

 ous. A species of fluke [ParamphistomuTn eerin or a closely related 

 s})ecies) is occasionally found in North American cattle, especially 

 grass-fed cattle, attached to the inner surface of the first stomach 

 (fig. 17). This worm is about one-half inch long, and somewhat 

 conical in shape; hence the name, conical fluke, by which it is some- 

 times known. Although this parasite has been accused of producing 

 serious ejffects, it is generally considered harmless. 



