530 DISKA.SKS OF CATTLE, 



hloijd vessels. According to Xoe, they are spread from one animal 

 to another by stable flies (see p. .j()8), but this lias not been definitely 

 prove<l. Tlie roundworms found occasionally in the anterior cham- 

 ber of the e^'e (see p. 531) are perhaps immature forms of this species 

 Avhicli have readied this location diirinfr tlieir migration. 



LUNG WORMS. 



Lung Avorms {Dirti/O' (niju.s rlriparns^ fig. 24) in cattle are thread- 

 like worms 2 to 4 inches long, found in the bronchial tubes and 

 producing a ccmclition known as verminous bronchitis. The life 

 history of the parasite is not fully known, but infection is evidently 

 derived through the medium of pastures where infested cattle have 

 grazed- In the later stages of the disease the cattle cough, especially 

 at night. Young cattle are more seriously ali'ected than old animals. 



Treatmerd for lung wonns. — A'arious treatments have been advo- 

 cated for lung worms, including fumigating Avith different substances 

 and injections of remedies into the 

 trachea by means of a large hypo- 

 dermic syringe or by a special 

 spraying apparatus, but none have 

 been very successful from a prac- 

 tical standpoint. About all that 

 can be done is to feed affected ani- i'i<;. 24.— Liin« worm {Dutyocouius nri- 



1 n 1 J. i j-1 -C „ parttn) of tattle. Outlines sliowinn u.it- 



mals well and protect them from „^^„ ^.^^ ^^ „,^,^ ^,,j,„^.„) ^„„ ,..,„„,, 

 exposui'e. leinoving them from the 



pasture and keeping them in dry yards or staldes maintained in a 

 cleanly, sanitary condition. 



The methods of prevention in general are similar to those described 

 under tlie discussion of the twisted stomach worm (p. r>21). 



PARASITES OF THE BLOOD. 



Certain flukes {HchUtoHonw hocis and related species) which live 

 in the blood vessels (the large veins) of cattle in tropical and sub- 

 tropical countries cause bloody urine and diarrliea. the feces being 

 mixed with blood. These ])arasites have not yet been discovered in 

 the United States, although the natural conditions are such in some 

 parts of the country that they are liable to become established if 

 introduced. 



The embryos of Sctar'm luhiato-pafUlosa (p. 529) which occtir in 

 the blood may be found by microscopical examination. They ap- 

 parently cause no trouble. 



Tlie organism which causes Texas fever is a protozoan parasite 

 {PiropJa.ymo hn/rminini)) of niicroscoi)ic size. Avhich liA'es in the blood 



