Diagnosis. 77 



will succumb, while hogs die from the disease only in very 

 exceptional cases. The course of the affection is influenced by 

 the occurrence of secondary infections. 



The duration of the disease also varies a good deal; in 

 the great majority of grave, and hence unfavorable, cases, the 

 duration may be two, three or four months. Deviations in 

 either direction are, however, frequent. On the other hand, the 

 disease may last more than four months, even over one year, 

 particularly in adult strong animals; while on the other hand, 

 it may take a fatal issue wdthin a few days or w^eeks (mthout 

 exception only in younger animals, particularly in calves). In 

 such cases one generally finds a larger bronchus obstructed by 

 masses of worms, or a rapidly spreading bronchopneumonia. 

 In its mild form the disease ends in recovery. In cases of me- 

 dium intensity recovery occurs, usually in hogs, frequently in 

 calves, after regulation of the diet; wdiile sheep and goats, 

 everything else being equal, generally succumb, especially 

 younger, weakened animals, or those which are in the later 

 stages of pregnancy. The very severe forms usually end fa- 

 tally. The advent of improvement is marked by a gradual 

 diminution of the cough and by amelioration of the other symp- 

 toms. 



Recovery is not always complete. Some animals, espe- 

 cially sheep and goats, still suffer in their nutrition after the 

 disappearance of the catarrhal symptoms, and there may be a 

 chronic wasting away with tinai death, unless the animal is 

 slaughtered in time. 



Diagnosis. Neither the symptoms of bronchial catarrh nor 

 the subsequent cachexia are to be looked upon as characteristic 

 symptoms of the disease. A diagnosis can only be made after 

 the detection of the worms or their ova or embryos. The worms 

 can be recognized with the naked eye in the coughed up sputum ; 

 if they are absent microscopic examination will detect the ova 

 or embryos if present. Embryos of lung-^vorms are also found 

 in the feces of infected animals (Schlegel, Plana, Eichhorn). 



Since cattle often swallow sputum which has been coughed up, Andersen 

 reeoniniends, after an attack of cough, the introduction into the pharynx of a 

 rod armed at one end with a cotton plug; the secretion obtained on the" plug of 

 cotton is then examined. Bergeon has used this method with advantage. Hasen- 

 kanip 's lung-mucus catcher might also be used with advantage. In an emergency 

 masses of secretion may be removed from the pharynx with the hand. 



Symptoms which are more or less similar to those of lung- 

 worm disease are found in catarrhal pneumonia from other 

 causes, as well as in enzootic pneumonia of young animals. 

 These affections, however, lead from the start to more or less 

 marked disturbances of the general health with fe])rile eleva- 

 tion of temperature and they do not lead to the formation of 

 abundant masses of secretion ; both forms of pneumonia usually 

 occur in very young animals. Differential diagnosis between 

 cases of lungworm disease associated with bronchopneumonia 



