No. 6. 



Rot in Sheep. 



197 



to half an inch in greatest breadth. The 

 head is of a pointed form, round above, and 

 flat beneath; and the mouth opens laterally 

 instead of vertically. There are no barbs 

 or tenacula, as described by some authors. 

 The eyes are placed on the most prominent 

 part of the head. No difference of se.x has 

 yet been discovered in the fluke-worm, and 

 it is believed to be an hermaphrodite. 



Then, is the fluke-worm the cause or the 

 effect of the rot"! To a certain degree both. 

 They aggravate the disease; they perpetu- 

 ate a state of irritability and disorganiza- 

 tion, which must necessarily undermine the 

 strength of any animal ; they unnaturally 

 distend, and consequently weaken the pas- 

 sages in which they are found ; they force 

 themselves into the smaller passages, and, 

 always simming against the stream, they 

 obstruct the flow of the bile, and produce 

 inflammation by its accumulation; they con- 

 sume the nutritive juices, by which the 

 neighbouring parts should be fed; and they 

 impede the flow of the bile into the intes 

 tines, by clogging up the ducts with their 

 excrement and their spawn. Notwithstand 

 ing all this, however, if the fluke follows 

 the analogy of other entozoa and parasites, it 

 is the effect and not the cause of the rot. 

 The ova are continually swallowed by the 

 sound animals and the diseased ; but it is 

 only when the fluids are altered, and some- 

 times essentially changed, and the condition 

 of the digestive organs is materially im- 

 paired, that their appearance is favoured, or 

 their multiplication encouraged. 



What, then, is the cause of the rot in 

 sheep 1 



The knowledge of the cause can alone 

 guide us to a cure, or at best, to the preven- 

 tion of it. It docs not arise from deficiency 

 of food ; a sheep may be reduced to the low- 

 est state of condition — he may be starved 

 outright, but the liver would not be necessa- 

 rily as off^en in a diseased state. It is not 

 to be traced to the effects of sudden flush of 

 grass. The determination of blood to the 

 head, diarrhoea, dysentery, might be thus 

 produced, but not one symptom resembling 

 rot. Some persons, led away by a favourite 

 theory, have traced it to defective ventila- 

 tion ; but in the closest keeping to which 

 the British sheep is usually committed, there 

 is no foul air to be got rid of, and defective 

 ventilation would be words witliout meaning. 

 The rot in sheep is evidently connected 

 with the soil or the state of the pasture. It 

 is confined to wet seasons, or to the feeding 

 on ground moist and marshy at all seasons. 

 It has reference to the evaporation of water, 

 and to tlie presence and decomposition of 

 moist vegetaiale matter. It is rarely or al 



most never seen on dry or sandy soils and in 

 dry seasons. In the same farm there are 

 certain fields on which no sheep can be 

 turned with impunity. There are others 

 that seldom or never give the rot. 



Some seasons are far mora favourable to 

 the development of the rot than others, and 

 there is no manner of doubt as to the char- 

 acter of the seasons. After a rainy sum- 

 mer, or a moist autumn, or during a wet 

 winter, the rot destroys like a pestilence. 

 A return and a continuance of dry weather 

 materially arrests its murderous progress. 

 It is, therefore, sufficiently plain that the 

 rot depends upon, or is caused by the exist- 

 ence of moisture. A rainy season, and a 

 tenacious soil, are fruitful or inevitable 

 sources of it. 



But there is something more than moist- 

 ure necessary for the production of rot. The 

 ground must be wet, and its surface exposed 

 to the air; and then the plants, previously 

 weakened or destroyed by the moisture, will 

 be decomposed; and in that decomposition, 

 certain gases or miasmata will be developed, 

 that cannot long be breathed, or scarcely 

 breathed at all by the sheep, without pro- 

 ducing the rot. 



Chemistry, even in its present advanced 

 state, will afford no means of analyzing 

 these deleterious gases; and it is a matter 

 of little practical consequence to be ac- 

 quainted with their constituent principles. 

 Then the mode of prevention consists in al- 

 tering the character of as much of the dan- 

 gerous ground as he can, and keeping his 

 sheep from those pastures which defy all his 

 attempts to improve them. 



Treatment. — In the early stage of the 

 disease, bleed. Abstract, accordmg to the 

 circumstances of the case, eight, ten, or 

 twelve ounces of blood. There is no dis- 

 ease of an inflammatory character, at its 

 commencement, which is not benefited by 

 an early bleeding. To this let a dose of 

 physic succeed — two or three ounces of Ep- 

 som salts; and to these means let a change 

 of diet be immediately added — good hay in 

 the field, and hay, straw, or chaff" in the 

 straw-yard. 



To this should be added — a simple and a 

 cheap medicine, but that which is the sheet 

 anchor of the practitioner here — common 

 salt. The farmer is beginning to be aware 

 of the valuable properties of salt in pro- 

 moting the condition, and relieving and pre- 

 venting many of the diseases of ail the do- 

 mesticated animals. In the first place, it is 

 a purgative, inferior to few, when given in 

 a full dose; and it is a tonic as well as pur- 

 gative. Its first power is exerted on the di- 

 gestive organs — on the stomach and intes- 



