IIO VETERINARY PARASITOLOGY 
rumination, and so pass down the trachea. Other 
observers state that the embryos are carried to the 
bronchi or lungs in the blood-stream. 
SymptToms.—These vary considerably according to 
the site and variety of the parasite present. For 
instance, in sheep Strongylus filaria mainly produces 
symptoms of bronchitis, while Sivongylus rufescens pro- 
duces those of pneumonia. 
In Bovines.—Strongylus micrurus of the calf produces 
either bronchitis or pneumonia, according to whether 
the worms are seated in the large bronchi or in the 
smaller divisions deeper in the lung. 
In simple cases, where the symptoms are those of 
bronchitis, there is gradual wasting and emaciation, 
with pitched coat and general signs of unthriftiness. 
Cough is always present. In character it is frequent, 
short, and harsh; the head is held down, and a quantity 
of thick ropy saliva issues from the mouth. The dis- 
charge from the nose may contain worms, eggs, or 
embryos. The appetite is usually at first undisturbed. 
As the disease progresses the cough becomes weak and 
faint, and the animal gasps for breath. 
In those cases in which the worms are situated in the 
smaller divisions of the bronchi there are present 
symptoms of pneumonia, more or less acute, with rapid 
breathing, elevated temperature, and anorexia, In 
some cases the symptoms are indistinguishable to the 
naked eye from those of tuberculosis. In the former 
type of the disease the degree of mortality is low, pro- 
viding the animals are well nourished, but in the latter 
type death is a very common sequel, and the degree of 
mortality may be anywhere from 20 to 80 per cent. 
Intestinal strongylosis often accompanies husk, as the 
conditions necessary for the development of all these 
parasitcs are identical. 
Adult cattle usually show less serious symptoms. 
