The Property of Mr. Jonas Webb of Babraham, near Cambridge, which obtained Prizes in their respective classes at the Smithfield Cattle Show, Decr. 1839.
SHEEP.
PRELIMINARY REMARKS.
Many of the diseases to which sheep are subject can be traced to want of due care in their management. The common practice of letting them range in marshy lands is one of the principal causes of disease.
The feet of sheep are organized in such a manner as to be capable, when in a healthy state, of eliminating from the system a large amount of worn-out materials—excrementitious matter, which, if retained in the system, would be injurious. The direct application of cold tends to contract the mouths of excrementitious vessels, and the morbid matter accumulates. This is not all. There are in the system numerous outlets,—for example, the kidneys, lungs, surface, feet, &c. The health of the animal depends on all these functions being duly performed. If a certain function be interrupted for any length of time, it is sure to derange the system. Diseases of the feet are very common in wet situations, and are a source of great loss to the farming community. Hence it becomes a matter of great importance to know how to manage them so as to prevent diseases of the feet.
Professor Simonds says, "No malady was probably so much feared by the agriculturist as the rot; and with reason, for it was most destructive to his hopes. It was commonly believed to be incurable, and therefore it was all important to inquire into the causes which gave rise to it. Some pastures were notorious for rotting sheep; on other lands, sheep, under all ordinary circumstances, were pastured with impunity; but, as a broad principle, it might be laid down that an excess of moisture is prejudicial to the health of the animal. Sheep, by nature, are not only erratic animals, wandering over a large space of ground, but are also inhabitants of arid districts. The skill of man has increased and improved the breed, and has naturalized the animal in moist and temperate climates. But, nevertheless, circumstances now and then take place which show that its nature is not entirely changed; thus, a wet season occurs, the animals are exposed to the debilitating effects of moisture, and the rot spreads among them to a fearful extent. The malady is not confined to England or to Europe; it is found in Asia and Africa, and occurs also in Egypt on the receding of the waters of the Nile.
"These facts are valuable, because they show that the cause of the disease is not local—that it is not produced by climate or temperature; for it is found that animals in any temperature become affected, and on any soil in certain seasons. A great deal had been written on rot in sheep, which it were to be wished had not been. Many talented individuals had devoted their time to its investigation, endeavoring to trace out a cause for it, as if it originated from one cause alone. But the facts here alluded to would show that it arose from more causes than one. He had mentioned the circumstance with regard to land sometimes producing rot, and sometimes not; but he would go a step further, and ask, Was there any particular period of the year when animals were subject to the attack? Undoubtedly there was. In the rainy season, the heat and moisture combined would produce a most luxuriant herbage; but that herbage would be deficient in nutriment, and danger would be run; the large quantity of watery matter in the food acting as a direct excitement to the abnormal functions of the digestive organs. Early disturbance of the liver led to the accumulation of fat, (state of plethora;) consequently, an animal being 'touched with the rot' thrived much more than usual. This reminded him that the celebrated Bakewell was said to be in the habit of placing his sheep on land notorious for rotting them, in order to prevent other people from getting his stock, and likewise to bring them earlier to market for the butcher."
Referring to diseases of the liver, Professor S. remarked, that "the bile in rot, in consequence of the derangement of the liver being continued, lost the property of converting the chymous mass into nutritious matter, and the animal fell away in condition. Every part of the system was now supplied with impure blood, for we might as well expect pure water from a poisoned fountain as pure blood when the secretion of bile was unhealthy. This state of the liver and the system was associated with the existence of parasites in the liver.