526 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



feed trough so that the sheep can not avoid touching in the attempt 

 to get the grain. 



The treatment of a sheep already affected is unsatisfactory. In- 

 jecting turpentine into the nostril as so often recommended reaches 

 only a few that may not be in the sinus. Trephining or opening 

 the skull is rather theoretical and not practical on large flocks. Oc- 

 casionally fumigating the stable with turpentine or smoke from tar 

 will palliate the catarrh. If the disease develops in the fall, fatten 

 as fast as possible and dispose of to the butcher. If in the spring use 

 good care and feed to cany the sheep along until the grub comes 

 away. 



SHEEP TICK. 



The sheep tick as it is commonly called is one of the commonest 

 of the parasites affecting sheep. It is not a true tick but a wingless 

 fly. This parasite is not a native of this country, but has been 

 brought here through importation from Europe. It was first rather 

 confined to the eastern states, but owing to the purchase of breeding 

 stock, and subsequent traffic in sheep, it has been carried to a large 

 percentage of the flocks in this state. The losses occasioned are not 

 from destroying the sheep by killing, but from the lack of thrift 

 occasioned by their irritating and biting the skin. It is difficult to 

 estimate the losses occasioned in a flock by the presence of this para- 

 site, but where they become numerous there can be no doubt but 

 that it amounts to a considerable sum. The state has been called 

 upon to investigate cases of supposed scab that were due to ticks. 



The parasite of this disease, Melophagus ovinus, Linn, is a 

 wingless fly. It has six well developed legs, a short, flat head set 

 closely upon the body and a large, oval abdomen. Their resem- 

 blance to the tick, with its large abdomen, small head and eight 

 slender legs is not so very close when critically examined. The full 

 grown tick is about one-fourth of an inch in length and about one- 

 third as wide as long. 



The body is short, flattened above and below, very tough and 

 leathery in character. The color varies from an ashen to reddish 

 gray and quite a bright red, dependent upon the quantity of blood 

 imbibed and the time elapsed since the meal. The head is broad and 

 very flat and somewhat sunken into the thorax. The eyes are small 

 and on about a level with the head. The proboscis is tubular and re- 

 inforced at the upper part. Its end is armed with teeth. The 

 thorax is nearly square and bears the strong legs. The abdomen is 

 bag like. The legs are each provided with two sharp claws. The 

 legs and body are covered with bristles. There are no wings but a 

 couple of bristle spots take their place. The sexes may be separated 

 by their size and the form of the sexual apparatus. 



The tick being wingless depends wholly upon its ability to 

 crawl for locomotion. It is able to crawl through the wool at quite 

 a lively rate. It bites, and sucks the blood for its food. Formerly it 

 was thought that it lived in part upon the oily matter of the wool 

 and the epidermis of the skin. The fact that the tick soon starves 

 to death even when kept in fresh wool practically settles the matter- 



