Leeches. 473 



Symptoms. These vary according to the part of the body at- 

 tacked : In case of the limbs, the leeches, at first overlooked by 

 reason of their small size, soon fill themselves with blood and 

 stand out singly or in clusters, while the parts may be more or 

 less bloodstained. Nervous horses are rendered violent and un- 

 manageable. 



The m,outh, nose and pharynx are the most common points of 

 attack. The small, fasting leeches, like blackened fragments of 

 grass stems, are taken in with the green food or the water, and 

 fasten themselves on the alse nasi, the Schneiderian membrane, 

 the lips outside or inside, the lower surface of the tongue, the 

 frenum, the cheeks, palate, soft palate, pharynx or larynx. When 

 they are on the buccal mucosa, the animal host may swallow the 

 oozing blood so that it does not appear at the lips excepting 

 during work, when the bloody saliva escapes beside the bit or 

 from the lips generally. The irritation may lead to constant 

 movements of lips, jaws or tongue, and in extreme cases to re- 

 fusal of food even. A careful examination of the opened mouth 

 will reveal the presence of the leeches. Further irritation may 

 come from local infection of the wounds or the introduction of 

 barley beards and other spikes, causing profuse salivation. 



In the nasal fosses or pharynx the leeches cause a bloody dis- 

 charge from the nose with sneezing, snuffling or cough, according 

 to their situation. 



When attached to the larynx or its upper margin, they cause 

 violent spasmodic coughing and dyspnoea, and it may be prompt 

 suffocation. 



Bijard has found a leech attached to the conjunctiva of a horse, 

 producing acute inflammation and suppuration mingled with 

 blood so that the trouble was at first attributed to a blow. 



Guyon has found them in the vagina in mare, mule and cow. 

 Here irritation with bloody mucopurulent discharge directed at- 

 tention to the annelids. 



The numbers taken in are sometimes remarkable. Blaise found 

 185 of the average thickness of the little finger in the pharynx of 

 the horse, and Reynaud 192 in the interior of the larynx. 



The following experiments were made by Guyon on small ani- 

 mals. Young horse leeches were introduced into the nasal cham- 

 bers and rectum of rabbits, and into the oviduct and oesophagus 



