260 PARASITES OF THE DOMESTIC ANIMALS 



cases with violent attacks occurring several times a day, the gasping 

 animal may fall prostrated and die from asphyxiation. 



The mucus expelled by the coughing is frequently streaked with 

 blood and contains the worms which are often collected in masses. It 

 is to these masses obstructing the large bronchi that the suffocation is 

 due. 



Course and Prognosis. — What has been said as to influences gov- 

 erning the duration and intensity of the malady in sheep will, in general, 

 apply to cattle also. The prognosis, especially in calves, is usually 

 unfavorable. Death is generally brought about in three to six months 

 by asphyxia or extreme cachexia and exhaustion. 



For Post-mortem Appearance, Development and Etiology, Control, 

 and Treatment, refer to pp. 262-265. 



Bronchial and Pulmonary Strongylosis of the Pig 



Two strongyles are met with in the respiratory tract of the hog. 



1. Metastrongylusapri (Strongylusapri; St. paradoxus). Fig. 133. 

 Metastrongylinse (p. 256). — The body is white or brown. The mouth 



has six Hps. The bursa of the male is bilobate, each lobe 

 sustained by five ribs. The spicules are slender and very 

 long, measuring about 4 mm. (3/16 of an inch) and each 

 terminated in a barb. The tail of the female terminates 

 by a short hook-like process. The vulva is on a slight 

 eminence immediately in front of the anus. 



Length of female, 2-5 cm. (3/4-2 inches); male, 1.2-2 

 cm. (1/2-3/4 of an inch). 



The eggs are oval, 57-100 microns in length by 39-72 

 microns in breadth. They contain developed embryos at 

 the time they are deposited and these are liberated in 

 Fig. 133.— the broncM. 

 apri;^^ma?e^ Tt The embryos at the time of their hberation measure 

 right, female at 220-250 microns in length and 10-12 microns in thickness, 

 left, — natural -pj^g worm is parasitic in the respiratory tract of do- 

 mestic and wild hogs, occasionally of sheep. 



2. Metastrongylus brevivaginatus. Metastrongyhnae (p. 256). — 

 This species has for a long time been confounded with the preceding 

 tmder the name of Strongylus paradoxus. It differs from it in the shape 

 of the bursa and in the spicules which are short, each terminating in 

 itwo barbs. 



The worm is parasitic in the respiratory tract of domestic hogs. 



Occurrence and Symptoms. — While the presence of strongyles in 

 the bronchi of pigs has been known for a long time, it is not as frequently 

 observed in these animals as in sheep and calves. Heavy infestations 



