800 noAiJi) 1)1 AC i;i( ri.i TK'K. 



surnniinlrd liy .-i xcsiclc or Ijl.iddti- like body, visible to tlic naked eye. 

 Surniiiiidiiifi tlie iiioutli aie siv lolies. Die two laleia! ones liein;.' tlio 

 hirfji'st. The color is wlnlisli or lirown. 



Lesions. 'I'liese are nsnally sli.t:;ld and depeinl on tlie nnndx-r ol' 

 liviiiu: worms |)resenl and tlie dnration of the infection. The worms are 

 foiinil in tin* bronchial tubes mixed with the mucous. "When badly 

 infected, the mucous membrane liuin.ir tlie smaller tubes hefomcs inflamed. 

 As well as irritatinj; the nir tubes, it acts as a nicdianical obstruction 

 and may piny" up the smaller bronchi and will cause a lobular pneumonia. 

 The involved air cells usually return to th<> normal but may «() Ihrou.ah 

 other patholosjical chanii'es. In s(uue cases the effect is to eulars:e the 

 l)ronclii or to cause saculatiou. 



Method of Infection. — The life history of tin* lung worm is not fully 

 known. In most domestic animals infection with lung worms depends 

 largely on the humidity of the soil, and is more prevalent on swainity 

 pastures containing ]»onds and stagnant water tii;in it is on high groiuid. 

 On wet years this disease is more common than on dry years. I>ung 

 worms are often present in pigs when k<'pt under the best ])ossible 

 conditions. 



The e.g.gs are laid in the lironchial tuixs. I'.efore they hatch it seems 

 necessary for them to be expelled by coughin.g and undergo a part of their 

 development outside of the l»o(|y. .lust what these chan.i^es are is not 

 known. In all probabilities the pig becomes infected through the fofxl 

 supply, by rooting in the mud aiul by iidialin.g the immattu'e form in 

 the (lust that may accumulate at)out the sleeping quarters and pens as 

 a result of the mud carried on the bodies of the animals. 



Symptoms. — The disease is largely confined to pigs. The lirst .symp- 

 toms begin as a cough, occurring upon leaving the bed, after exercise and 

 after eating. In badly infected cases the paroxysm of coughing is quite 

 severe. Keginning slowly and becoming harder and harder, and linally 

 the pig will i)ut the nose on the ground and press bard while coughin.;;. 

 The paroxysm ends by the expulsion of some mucus or by vomiting. 

 This is referred to in the journals as whooping cough in pigs. The cough 

 may become frequent and persistent and is generally spoken of as chroni«-. 

 In the majority of cases the infection is so slight that the presence of 

 the Inng worm is not suspected by the oAvner. The appetite remains good 

 in these cases, and the thriftiness of the pig is not interfered with. Death 

 seldom occurs and as the i)ig grows and thiives. it gradually recovers from 

 the affection. 



Treatment.— The most important part of the treatment is to keep 

 the pig in a healthy, growing condition. The hygienic conditions in the 

 pastures and pens should l»e as nearly perfect as possible. The drinking 

 water should be i)ure and the ponds and miul holes drained or filled in. 

 Clean watering troughs and feeding rt<M)rs aie also necessary. The sletjp- 



