76 



ASCAEID^ AND FILAKID^. 



is found in the large intestine of the horse and other Equidse : 

 it is known as Oxyuris curvula (fig. 28), and may often be seen 

 hanging from the horse's anus. We have known these worms 

 cause very serious emaciation in horses, but they are easily 

 cleared out by the use of santonin powder. This vermifuge 

 expels many females full of eggs, and immature forms. A long- 

 tailed dimorphic form called Mastigodes (fig. 29) has been 

 described by Nitzsch. Males are comparatively rare. These 



worms, I have observed, 

 are passed usually in the 

 morning, generally num- 

 bers together, the excreta 

 of the host being full of 

 their ova. Very closely 

 related is the obnoxious 

 little human worm, 0. 

 vermiaularis. 



The Filaridw are long 

 and filiform worms, all of 

 which are found in con- 

 nective tissue and never 

 in the intestine. A com- 

 mon form in the horse is 

 Filaria papillosa, a white 

 worm about six inches 

 long found in the per- 

 itoneal cavity. Thousands have been taken out of the thoracic 

 cavity of the horse at one time. They sometimes even penetrate 

 the scrotum, and a few have been found in the eye. The 

 life-history of this worm, like many others, is quite unknown. 

 Another species, known as F. immitis, is found in the heart 

 and pulmonary artery of the dog. Neither, however, occasions 

 sufficient loss to call for further remarks. 



Thymol administered as stated in Appendix I. is certain to 

 free the intestines of Ascarid parasites. 



Fig. 28.— Oxydres of Horse. 



Females with sliort tails (=Curwu?a), 

 liet. (From Neumann.) 



