LECTURE LI. 



VERMINOUS BRONCHITIS, NASAL GRUB, AND CATARRH. 

 VERMINOUS BRONCHITIS. 



Definition. — A disease of the bronchial tubes and lungs, 

 caused by minute round worms. The worms are similar in dif- 

 ferent domestic animals, but each animal has its own species. 

 There is therefore little danger of infection from one kind of do- 

 mestic animals to another. 



Life history of the parasite. — Young sheep, young goats, 

 cattle imder two years of age, and young pigs are susceptible to 

 this disease. The mature worms are found in the bronchial tubes 

 as well as eggs and embryos. These may be coughed out and 

 ultimately reach pools or small ponds of stagnant water. The 

 larvae are usually swallowed with the food or drink and some of 

 them ultimately reach the trachea probably by way of the larynx. 

 It is possible that the eggs may be inhaled directly with particles 

 of dust. Infection occurs mainly in the spring. The parasitism 

 remains long dormant, slowly developing until fall. The disease 

 seems to be especially common in wet years. Embryos and eggs 

 are very resistant and the parasite is very tenacious of life at all 

 stages. 



Symptoms. — At first there is a bronchial catarrh ; later a 

 chronic anaemia, with progressive loss of flesh, and strength. 

 There is a cough which at first is rather harsh, and later very 

 weak. The cough is worse when animals are excited and when 

 they move around. Sometimes small balls composed mainly of 

 worms may be coughed out and actually seen. Respiration is dif- 

 ficult and in some cases wheezing. Calves are able to resist rather 

 longer than sheep. 



On examination post mortem there may be found masses 

 of minute thread-like worms in the trachea and bronchial tubes, 

 with considerable quantity of purulent and viscid liquid in the 



