Page:Encyclopædia Britannica, Ninth Edition, v. 24.djvu/225

Rh VETERINARY SCIENCE 205 or extensive sores, oxide of xinc ointment should be applied. But treatment should not be adopted unless there is general infection over a wide extent of country. All diseased animals should be destroyed, as well as those which have been in contact with them, and thorough disinfection resorted to. Diseases of the Pig. ne The pig may become affected with foot-and-mouth disease (see nie or MURRAIN), and it also has its own particular variola. But the dis- ir. ease special to it, and which causes enormous losses, is swine plague. This scourge, known in America as hog cholera, is a specilic con tagious fever, or fevers, for it is extremely probable that two diseases are included under this designation. It is generally very rapid in its course, death ensuing in a very few days ; and when the animal survives recovery is protracted. After a period of three or four days to a fortnight from exposure to infection, the animal exhibits signs of illness by dulness, weakness, shiverings, burying itself under the litter, disinclination to move, staggering gait, great thirst, hot dry snout, sunken eyes, loss of appetite, and greatly increased pulse, respiration, and temperature. Red and brown patches appear on the skin ; there is a hacking cough ; nausea is followed by vomiting ; pressure oil the abdomen causes extreme pain ; diarrhoea ensues ; the hind limbs become paralysed ; stupor sets in ; and the animal perishes. Treatment should not be at tempted when there is danger of the infection extending to other pigs. If treatment be used, nursing ought to be the chief element ; sloppy food, in which small doses of carbolic acid and oil of turpen tine have been mixed, should be given, and these should be followed by tonics when convalescence sets in. To suppress the disease, kill all affected pigs, and if necessary those which have been in contact with them ; burn or bury deeply the carcases and litter ; and disinfect everything likely to have been contaminated by the virus. Diseases of the Dog. The contagious diseases of the dog are likewise very few, but per. the one which attracts most attention is common and generally serious. This is what is popularly known as distemper. It is peculiar to the canine species, for there is no evidence that it can be conveyed to other animals, though the different families of Car- iiimra appear each to be liable to a similar disease. Distemper is a specific fever which most frequently attacks young dogs, its effects being primarily developed in the respiratory passages, though the brain, spinal cord, and abdominal organs may subse quently be involved. Highly bred and pet dogs suffer more severely than the commoner and hardier kinds. It is a most infectious disease, and there is much evidence to prove that it owes its ex istence and prevalence solely to its virulence. One attack confers immunity from another. The symptoms are rigors, sneezing, dul ness, loss of appetite, desire for warmth, and increased temperature, respiration, and pulse. The eyes are red, and the nose, at first dry and harsh, becomes smeared with the discharge which soon begins to flow from the nostrils. Suppuration also begins at the eyes ; vision is more or less impaired by the mucus and pus, and often the cornea becomes ulcerated, and even perforated. There is a cough, which in some cases is so violent as to induce vomiting. Debility rapidly ensues, and emaciation is soon apparent ; diarrhoea in the majority of cases sets in ; the body emits an unpleasant odour ; ulceration of the mouth is noticed ; the nostrils become obstructed by the discharge from them ; convulsions generally come on ; signs of bronchitis, pneumonia, jaundice, or other complications manifest themselves ; and in some instances there is a pustular or vesicular eruption on the skin. In fatal cases the animal dies in a state of marasmus. Many which recover are affected with chorea for a long time afterwards. Here, again, good nursing is all-important. Comfort and cleanliness, with plenty of fresh air, must be ensured. Debility being the most serious feature of the disease, the strength should be maintained or restored until the fever has run its course. Light broth, beef tea, or bread and milk, or these alternately, may be allowed as diet. Preparations of quinine, given from the com mencement of the attack in a little wine, such as sherry, have proved very beneficial. Often a mild laxative is required. Com plications should be treated as they arise. The disease being ex tremely infectious, precautions should be adopted with regard to other dogs. The formidable affliction known as RABIES (q.v.) has been treated of under that name. Itiblinyraphy.J. H. Steel, Treatise on the Diseases of the Dog; J. W. Hill, Management and Diseases of the Dog (London, 1878); W. Youatt, The Day (Lon don, 1851); D. Blainc, Canitie J atkulugy (London, 1851); W. Mayhew, Diseases of the Dog (London, 1S65). PRINCIPAL PARASITES OF DOMESTIC ANIMALS. i horse. Perhaps the commonest worm infesting the horse is Ascaris megaloccphala or common lumbricoid. The males are from 6 to 8 inches long, females 7 to 17 inches. It is found in almost every part of the intestinal canal, but generally in the small intestines. The symptoms produced in the horse by this worm are colicky pains, which occur intermittently, an unhealthy condition of the skin, and staring coat. Although the animal feeds well, it does not im prove in condition, but is very &quot;tucked up,&quot; and the visible mucous membranes are very pale. In some instances pouches are formed in the coats of the intestines. There are many recipes for the expulsion of lumbricoid ; among the principal remedies is a mixture of emetic tartar, oil of turpentine, and linseed oil ; others are san- tonine, sulphate of iron, male fern, &c. titrongylus armatus or palisade worm was at first supposed to consist of two varieties, but it has been proved that these are simply different stages of growth of one parasite. It is a moderate-sized Nematoid worm, having a straight body, with a globular and somewhat flattened head, males 1 to 14 inches long, females 1 to 2 inches. It is found in the intestines, especially the double colon and caecum. The embryo is developed in the interior of the egg after its expulsion from the host, and is lodged in moist mud, where, according to Cobbold, it changes its first skin in about three weeks, after which it probably enters the body of an intermediate bearer, whence it is conveyed to the alimentary canal of the horse, its ultimate host, in food or water. From the stomach it bores its way into the blood-vessels, where it again changes its skin and gives rise to aneurisms. After a time it recommences its wanderings, and passes into the large intestines, where it rapidly acquires sexual maturity. It is a dung- feeder. Sometimes it passes into other tissues of the body (kidney, liver, &c.), and occasionally produces fatal results. This parasite is most dangerous to its equine host when it is migrating from one organ to another. It is principally found at the root of the anterior mesenteric artery, but it also gives rise to aneurism in the cceliac axis, the post-mesenteric and splenic arteries, and even the aorta. The common lumbricoid, the palisade worm, and the four- spined strongyle (S. tetracanthus}-& Q principally productive of colic. The last-mentioned worm, of which the male and female are about the same size, ^ to f inch long, is found in the caecum, colon, and duodenum. It is a true blood-sucker, and its development is very similar to that of S. armatus, except that, when in the intestines in the trichonemous stage, it pierces the inner coats, encapsules itself, and forms little pill-like masses, and then again enters the tissues of the intestines before becoming mature. The symptoms of its presence are loss of condition, more or less constant colicky pains, unhealthy coat, flabby muscles, abdominal distension, diarrhoea, fcetid and watery foeces, pale mucous membranes, great weakness, more or less frequent cough, and sometimes partial or complete paralysis, due to the formation of a clot of blood causing thrombosis of one of the principal vessels of the posterior extremities, thus interfering with the circulation of blood in the part supplied by the particular vessel. The treatment by which the common lumbri coid is expelled will suffice to expel these strongyles, but care must be exercised in administering oil of turpentine, as it very often irri tates the wounds caused by #. tetracanthus in the coats of the intes tines. Of course this treatment applies to the mature stage of these worms. Oxyuris curvula or pin worm is fusiform in shape, with smooth gently curved body (males 1^ to If inches, females 3i to 4| inches long). It is seated in the caecum and colon ; and, although not found in the rectum, it causes great irritation at the anus by the clusters of eggs which are deposited around that part in the form of yellowish crusts. This parasite is best treated by means of a cathartic, followed by sulphate of iron, also carbolic acid in 2A per cent, solution. The Cestodes of the horse are very insignificant, both as regards their size and the symptoms they create, the two principal being Teenia pcrfoliata and T. plicata. The former is the more common, but is only from 1 to 5 inches in length ; it is found in the ca?cum and colon, and is distinguished from T. plicata, not only by its length, but also by its rounder head. This last, which has a nearly square head, and is from 6 inches to 3 feet in length, occurs in the small intestines and stomach. Generally a horse may be proved to be infested with tape-worm by finding soine of the proglottides in the feces. The best remedy for the removal of Ttenia is extract of male fern, with oil of turpentine and linseed oil, given three days in succession. Gastrus equi or the common bot, though not a true helminth (see INSECTS, vol. xiii. p. 150), is classed with the parasites on account of its larval form living as a parasite. The bot-fly deposits its eggs on the hair of horses in such a position as to enable that animal, when licking itself, to take them into its mouth ; there the warmth and moisture of the tongue, combined with the pressure of licking, cause them to burst, and from each egg a small grub escapes, which sticks to the tongue, and then passes down into the stomach, where it fixes itself to the cuticular lining of the organ by a hook which it has on each side of its mouth. There it under goes no change (except that of growth, being at this time about 1 inch long) for about nine months, when it detaches itself, passes into the food, and is discharged with the f;eces. Of the parasites which infest cattle and sheep mention will only In cattle be made of Fnxiola hepatica or common fluke, which gives rise to and the disease called rot, and is more frequently met with in sheep .sheep.