258 PARASITES OF THE DOMESTIC ANIMALS 



3. S3mthetocaulus capillaris (Strongylus capillaris). Metastrongy- 

 linae (p. 256). — This worm like the preceding is thin and brownish in 

 color. The mouth has six papillae and the caudal extremity is pointed. 

 The caudal extremity of the male is curled spirally; bursa small and sup- 

 ported by seven ribs; spicules dentate. The vulva of the female is just 

 in front of the anus. 



Length of female, 20-22 mm. (7/8 of an inch); male, 14 mm. (9/16 of 

 an inch). 



The eggs are brownish in color. The embryos develop after the eggs 

 are deposited and are liberated in the pulmonary alveoli and bronchi. 

 After depositing the eggs the adult worms invade the lung tissue where 

 they die and become encapsulated. 



The worm is parasitic in the respiratory organs of the sheep and goat. 



Bronchial and pulmonary strongylosis of sheep and goats is due to 

 the presence of these worms together with their eggs and larvas in the 

 air passages and alveoh. The affection is usually a broncho-pneumonia, 

 though the symptoms presented will be somewhat subordinate to the 

 infecting species. If the infection is with Didyocaulus filaria, or this 

 dominates a pulmonary species coexisting in the same animal, the 

 bronchial symptoms will be the more prominent. On the other hand, 

 in an abundant infestation with Synthetocaulus rufescens the pulmonary 

 symptoms are likely to predominate. 



Symptoms. — Bronchial strongylosis of sheep and goats is usually 

 due to the presence of adults of the species Didyocaulus filaria in the 

 larger air passages, and in most all cases the pulmonary form is asso- 

 ciated with it. In general, the symptoms are those of a bronchial 

 catarrh. There is a short dry cough which at first is at long intervals. 

 Later this is more frequent and may become paroxysmal and accom- 

 panied by distressing attacks of dyspnoea. The bronchial secretion 

 expelled through the mouth and nostrils is frequently Imnpy and usually, 

 though not always, contains the worms with their eggs and embryos, 

 the latter found by examination of the material with the microscope. 

 At first the liveliness and appetite of the animal are retained and there 

 is no appreciable loss of flesh. If the number of the parasites remains 

 small there will continue to be little or no manifestation of their presence. 

 Relative to the degree of infestation, the symptoms may pass through 

 the gradations above given to extreme difficulty in respiration, emacia- 

 tion, pallor, and edema of the larynx, muzzle, and eyelids, the brisket 

 and other dependent parts of the body in some cases also becoming 

 edematous. Finally, in extreme weakness, the animal is unable to get 

 upon its feet and, in a condition of complete prostration, succumbs. 



Symptoms occasioned by the presence of strongyles in the pulmonary 

 air spaces and alveoli are in themselves less prominent than those of 

 verminous bronchitis. Attentive percussion over the thorax may reveal 



