The Animal Parasites of Sheep

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U.S. Government Printing Office, 1890 - 222 páginas
 

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Página 25 - On the under side it is of the same color, but not variegated in the same way, there being a dark spot in the middle of each ring. The feet are brown, the under side of the head is puffed out and white. The antennae are extremely small and spring from two lobes which are sunk into a cavity at the anterior and under part of the head. The eyes are purplish brown, and three small eyelets are distinctly visible on the top of the head. It has no mouth and can not, therefore, take any nourishment.
Página 41 - They had some difficulty in penetrating the thick skin, but usually succeeded by slipping their tube into a hair follicle. At first no itching or irritation was felt, except a slight twinge when the bills first penetrated the skin; but little swellings came on a day or two later which itched for over a week. The itching was far more persistent than with mosquito bites. They must in this way cause lambs much discomfort. It was at first thought that a fluid could be seen running from the parasite to...
Página 41 - Curtice who studied the parasites of the sheep most thoroughly, writes: "to feed them they were placed upon the back of my hand. By this means I could, with a lens, watch them bore into the skin and see the abdomen slowly enlarge as they drew in the blood. They had some difficulty in penetrating the thick skin, but usually succeeded by slipping their tube into a hair follicle. At first no itching or irritation was felt, except a slight twinge when the bills first penetrated the skin; but little swellings...
Página 30 - Snot Nose." Neumann gives an excellent description of the symptoms: "Three or four larva? of the (Estrus are frequently found in the frontal sinuses of sheep which, during life, have never manifested any symptoms. It is only when the larvae are numerous, and when they are quite well advanced in their development at the commencement of spring-time, that they occasion morbid troubles. The latter begin by a discharge, often unilateral, which is at first clear and serous, then thick and mucous. Frequently...
Página 28 - the fly touches this part of the " sheep, they shake their heads, " and strike the ground violently " with their fore-feet ; at the same " time holding their noses close to " the earth, they run away, looking " about them on every side, to see "if the...
Página 88 - The life of the embryo, from the time it leaves one sheep until it is found in another, is yet undiscovered. When present in considerable numbers in sheep it determines a disease which is not only detrimental to the value of the animal, but at times causes the death of large mimbers.
Página 56 - Of all the diseases of sheep in this country, scab is the most feared by the flockmaster. So insidious is its attack, so rapid its course, so destructive its effects, and so difficult is it to exterminate that it has justly earned the distinction of being more injurious than any other disease caused by external parasites. Scab alone, of the parasitic diseases, has become the...
Página 61 - ... chief poisons used in the dip are tobacco, arsenic and carbolic acid. Of these, tobacco is the favorite, because its use has not been followed by the fatality that has in times past followed the use of arsenic. Carbolic acid is too expensive to be used in large quantities, but is an excellent ingredient when only a few sheep are to be treated.
Página 28 - ... where they crowd together during the heat of the day, with their noses held close to the ground, which renders it difficult for the fly conveniently to get at the nostrils.
Página 57 - In places the wool is stuck together in masses; in others it fails, while in others, which are apparently sound, it can be easily plucked off. The rubbing and scratching indulged in by the sheep not only tend to tear away the wool but increase the irritation of the skin, which may become intensely inflamed and swollen and finally end in a superficial death of the part.

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