74 Luugworm Disease. 



Inflammation of the deeper layers of the bronchial wall 

 can be recognized by its thickness, sometimes also by the pres- 

 ence of small purnlent foci (peribronchitis). In such cases one 

 finds a proliferation of pulmonary tissue around the bronchi, 

 and white cicatricial bands are seen radiating from the bronchial 

 wall into the air-containing tissue. 



In hogs particularly pathologic changes are sometimes 

 found onlj' in the bronchi. These, however, frequently lead to 

 atelectasis of the neighboring pulmonary parenchyma. 



According to the observations of Osier, Blnmberg anfl Eabe, Strongylus 

 canis bronchialis produce In dogs wart-like nodules up to the size of a bean; 

 they are arranged like mushrooms on the surface of the trachea and of the larger 

 bronchi (tracheobronchitis verrucosa verminosa) : these nodules contain worms 

 which may project from under an uneven surface. In the pulmonary parenchyma 

 there are many gray subpleural nodules, like granules of sand, and these contain 

 each one worm. Osier also observed extensive bronchopneunionic inflammatory foci. 



The pleura pulmonalis of the affected animals frequently 

 appears mottled, thickened, but rarely covered with fibrinous 

 deposits, or adherent to the pleura costalis. According to Kitt, 

 the Str. commutatus sometimes produces pleuritic abscesses. 



In severe cases the other organs present evidences of ane- 

 mia and cachexia, especially subcutaneous edema and exudates 

 into the serous cavities. A very intense gastritis is, according 

 to Schlegel, of frequent occurrence. The bronchial glands are 

 usually swollen. 



Symptoms. The appearance of lung-worm disease is possible 

 at any time. It occurs, however, preferably in spring and fall 

 or during the period of pasturing. The climax is generally 

 reached in fall. 



The rei)orts of various authors on the appearance and occurrence of lungworm 

 disease do not quite agree with each other. According to Eailliet it is observed 

 mostly during the warm season ; according to Neumann, it occurs all the year 

 around, especially between March and October; according to Ziirn, in spring and 

 in fall; according to Friedberger & Frohner generally in fall; according to 

 Dieckerhoflf in calves toward the end of the pasturing season or even after its 

 termination. Csokor states that lung-worm disease in lambs appears in summer; 

 in older animals only in fall. Moussu claims that the disease is prevalent all the 

 year around, but reaches its climax late in the fall. 



The period between the ingestion of the worm brood and 

 the outbreak of the disease varies considerably according to 

 the intensity of the invasion and to the individual power of re- 

 sistance of the infected animal. Six to eight weeks elapse in 

 the majority of cases till the symptoms become manifest. After 

 a minor invasion and in strong adult animals the symptoms 

 of disease come on after several months, while after a severe 

 invasion, symptoms may be noticeable after some days. 

 Schlegel saw the disease 12 to 59 days after the infection of 

 goats, while Kasparek saw, as already mentioned, bronchopneu- 

 monic foci in infected calves only ly^ to 8 days old. 



The disease manifests itself, as a rule, in all species of 



