CHti<PTE<R XIII. 



IJYTESTIJY&L <P&R&SITES. 



A study of the anatomical structure of worms, their physiological phe- 

 nomena, and natural history is highly interesting, and productive of 

 valuable results ; still those considerations which relate directly to dis- 

 eased states in consequence of their presence, will he of far greater 

 practical importance to the reader. 



Dr. Cobbold in his able and exhaustive treatise on " The Internal Para- 

 , sites of our Domesticated Animals " states, " when people speak of worms 

 in the dog, they commonly refer to round and tape worms; and in place 

 of recognizing as they might, fully a score or more of intestinal parasites, 

 they are content to roll the entire series into three or four species only. 

 Thus, of the so-called lumbricoid and filariform worms, we have no less 

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

 is the marginated round worm." 



In the recognition and treatment of disorders consequent upon worms 

 it would seem wiser to leave the scientific study to zoologists and special- 

 ists, and to avoid confusion to reduce the classification in this work to the 

 limit of practicability. 



Probably no known disorder the dog is heir to is so destructive as intes- 

 tinal worms, it being estimated by reliable authorities, that at least three 

 fourths of the whole canine race are infected by the pest. 



Among the many different species of internal parasites some are found 

 in the liver, others in the eye; the giant strongle although rare, has been 

 known to infest the kidneys ; the wrinkled thread-worm sometimes reaches 

 the bladder; the cruel thread-worm selects the heart, death resulting sud- 

 denly in a convulsion, or deferred for a time, during which the dog is 

 racked by agonizing pain ; in the nasal cavities and even in the blood and 

 muscular tissues, parasites have been found. 



These facts are of interest but of little practical importance, and it is by 

 far more essential to consider those which are developed in the stomach 

 and intestines. 



