ROT IN SHEEP. 431 



suppose them to be ; on an examination being made of the 

 bile ducts of an affected animal, great numbers of these para- 

 sites may be found choking up the ducts, and surrounded 

 with masses of ova, which gradually descend into the intes- 

 tines, and are passed out with the f?eces, after which they 

 obtain an entrance into the soft-bodied mollusks found in 

 stagnant waters; thus it is that a wet season is so favourable 

 to the development of these parasites ; a dry season being 

 disastrous to the development of the ova. The embryos are 

 found to acquire considerable activity in the water, but pass 

 into the mollusks as stated above, and become encysted. 

 The parasite reaches its host again when the sheep drinks 

 the water containing the mollusk. The body of the mollusk 

 on reaching the stomach of the sheep becomes dissolved, 

 the hydatid escapes, reaches the liver, and deposits its ova, 

 which go the same round of existence. 



Symptoms. — The animal shows dulness and inactivity 

 in a well-marked degree, and there is a yellowish tinge of 

 the mucous membrane, covering the sclerotic coat of the eye, 

 best seen when the eyelid is pushed back. The abdomen 

 becomes large and pendant, constituting the condition com- 

 monly called 'pot-belly,' the back becomes razor-like, the 

 flanks tucked up, and there may be observed a strong ten- 

 dency to dropsical swellings in different parts of the body, 

 and more especially about the throat ; the animal's thirst is 

 insatiable, and the pulse is quick and weak. Anaemia is a 

 prominent symptom, the breathing is quick and short, and 

 perhaps there is a slight cough, which may partly be caused 

 by husk or hoose. The animal suffers from diarrhoea and 

 great weakness, followed by stupor and death. 



Treatment. — Early removal of the affected sheep to 

 another pasture is imperative. A laxative should be 

 administered, and the patient allowed plenty of food of a 

 highly nutritive character, such as pea-meal, oil-cake, etc. 



