OUR DOMESTICATED ANIMALS. 83 



so-called lumbricoid and filariform worms we nave no less 

 than eight or nine distinct forms, and of these the most 

 common species is the Margined Round Worm. 



This lumbricoid of the dog {Ascaris marginata) is pro- 

 bably identical with the moustached worm of the cat 

 {Ascaris mystax). It is sometimes described as the long 

 round worm. The males acquire a length of from two to 

 nearly three inches, whilst the females measure four, five, 

 or even six inches from head to tail. To afford some 

 notion of its prevalence, I may state that it was found at 

 Vienna in 104 out of 144 dogs dissected for the purpose ; 

 and Dr. Krabbe obtained it at Copenhagen in 122 in- 

 stances from the post-mortem examination of 500 dogs. 

 According to my own experiences, it occurs in English 

 dogs at the rate of about 70 per cent. Occupying prin- 

 cipally the small intestines, but often wandering into the 

 stomach, and occasionally also making its way into the 

 throat and nostril, this parasite is a frequent source of 

 severe intestinal disturbance, sometimes producing even 

 death itself. Cats and dogs alike are constantly throwing 

 them up, and it is a great relief to the host when they are 

 thus dislodged. Their occasional passage by the ordinary 

 outlet is also a matter of common observation ; but it is 

 not so very generally understood that these modes of 

 egress are often the result of a voluntary wandering on 

 the part of the guest. This is practically of some 

 moment, because it accounts for the circumstance of their 

 being sometimes found in the nasal passages and in other 

 unusual situations. The formidable nature of the symp- 

 toms which may thus be superinduced have been fully 

 indicated in a letter of mine which appeared in the Field 

 for Dec. 21, 1872. Under ordinary circumstances, the 

 symptoms in the dog are those of irregular intestinal 



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