stages as that of cowpox. The mortality may extend from 10%
in mild outbreaks to 90 or 95% in very virulent ones. Diseased
animals should be sheltered, and fed on nourishing food, especially
gruels of oatmeal flour or linseed; acidulated water may be
allowed. If there is sloughing of the skin or extensive sores, oxide
of zinc 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.
Foot-rot is a disease of the claws of sheep. It occurs most frequently in badly drained, low-lying, marshy land, and is caused Foot-rot. by the Bacillus necrophorus. Infection appears to be transmitted by cohabitation, litter, manure and infected pastures. The disease begins at the sole or between the claws and gradually extends, causing changes in the bones and tendons, with suppuration, degeneration of horn and sloughing. The symptoms are lameness, foot or feet hot, tender and swollen at the coronet; the horn soft and rotten. Affected sheep when feeding may rest on the knees, or, if fore and hind feet are involved, they lie down constantly. The claws must be cleansed, loose and underrun horn removed, abscesses opened, and the foot thoroughly disinfected and protected from further infection by an appropriate bandage. Some cases require daily dressing, and all affected feet should receive frequent attention. When large numbers of sheep are attacked they should be slowly driven through a foot-bath containing an antiseptic solution. Pastures on which foot-rot has been contracted should be avoided, the feet examined every month or oftener, and where necessary pared and dressed with pine tar.
Diseases of the Pig.
The pig may become affected with anthrax, foot-and-mouth disease and tuberculosis, and it also has its own particular variola. But the contagious diseases which cause enormous destruction of pigs are swine fever and swine erysipelas in Great Britain, hog cholera and swine plague in the United States, and swine erysipelas and swine plague in France, Germany and other countries of the European continent.
Swine fever is an exceedingly infectious disease, caused by a bacillus, and associated with ulceration of the intestine, enlargement Swine fever. of the lymphatic glands, and limited disease of other organs. It is spread with great facility by mediate as well as immediate contagion; the virus can be carried by apparently healthy pigs from an infected piggery, by litter, manure, food, attendants, dogs, cats, vermin, crates, troughs or anything which has been soiled by the discharges from a diseased pig. It is generally very rapid in its course, death ensuing in a very few days, and when the animal survives, recovery is protracted. After exposure to infection the animal exhibits signs of illness by dullness, weakness, shivering, burying itself in the litter, disinclination to move, staggering gait, great thirst, hot dry snout, loss of appetite, and increased pulse, respiration and temperature (105° F.). Red and violet patches appear on the skin; there is a hacking cough; nausea is followed by vomiting; diarrhoea ensues; the hind legs become paralysed; stupor sets in, and the animal perishes. Treatment should not be attempted. Notification of the existence of swine fever is compulsory, and outbreaks are dealt with by the Board of Agriculture and Fisheries. To suppress the disease kill all affected pigs and those which have been in contact with them; burn or deeply bury the carcasses and litter, and cover with quicklime. Disinfect everything that may have been contaminated with the virus.
Diseases of the Dog.
The contagious diseases of the dog are likewise very few, but the one which attracts most attention is common and generally serious. This is what is popularly known as distemper. 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 Carnivora 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 chord and abdominal organs may subsequently 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 existence and prevalence solely to its virulence. One attack confers immunity from another. The symptoms are rigors, sneezing, dullness, 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 soons 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 commencement of the attack in a little wine, such as sherry, have proved very beneficial. Often a mild laxative is required. Complications should be treated as they arise. The disease being extremely infectious, precautions should be adopted with regard to other dogs. Protective vaccines and antidistemper sera have been introduced by Lignieres, Copeman, Phisalix and others, but their action is uncertain.
The formidable affliction known as hydrophobia (q.v.) or rabies is treated of under that name.
Principal Parasites of Domestic Animals.
Perhaps the commonest worm infesting the horse is Ascaris equorum, or common lumbricoid. The males are from 6 to 8 in. In horse. long; females 7 to 17 in. They are found in almost every part of the intestine. When present in considerable numbers they produce slight intermittent colicky pains, an unthrifty condition of the skin, with staring coat. Although the horse feeds well, it does not improve in condition, but is “tucked up” and anaemic. Among the principal remedies is a mixture of tartar emetic, turpentine and linseed oil. Santonin, ferrous sulphate, common salt and arsenic are also employed. Sclerostomum equinum or palisade worm is a moderate-sized nematode, having a straight body with a somewhat globular head—males ¾ to 1½ in., females 1 in. to 2 in. long. This worm is found in the intestines, especially the double colon and caecum. The embryos are developed in the eggs after their expulsion from the host, and are lodged in moist mud, where, according to Cobbold, they change their first skin in about three weeks, after which they probably enter the body of an intermediate bearer, whence they are conveyed in food or water to the digestive canal of the horse, the ultimate host. They then penetrate the mucous membrane and enter the blood vessels, where they are sexually differentiated and give rise to aneurism. After a time they resume their wanderings and reach the large intestine, where they form small submucous cysts and rapidly acquire sexual maturity. They are most dangerous when migrating from one organ to another. They are found in the anterior mesenteric artery, but they also produce aneurism of the coeliac axis and other abdominal blood vessels, including the aorta. These parasitic aneurysms are a frequent cause of fatal colic in young horses.
Sclerostomum tetracanthum, or four-spined sclerostome, is about the same size as the palisade worm, and like it is found in the colon, caecum and small mtestine. It finds its way to the bowel in water or green fodder swallowed by the horse. It is a true blood-sucker, and its development is very similar to that of the S. equinum, except that it directly encysts itself in the mucous membrane and does not enter the blood vessels. The symptoms of its presence are emaciation, colicky pains, harsh unthrifty coat, flabby muscles, flatulence, foetid diarrhoea, anaemia, great weakness and, sometimes, hemorrhagic enteritis. Treatment of equine sclerostomiasis frequently fails, as the remedies cannot reach the encysted parasites. As germicides, thymol, areca, ferrous sulphate, tartar emetic, arsenic, sodium chloride, oil of turpentine, lysol, creolin and carbolic acid have been found useful.
Oxyuris curvula, or pin worm, is a common parasite of the large intestine. The anterior part of the body is curved and the tail sharply pointed. The male is seldom seen. The female measures 1 to 1½ in. in length. It is found in the caecum, colon and rectum, and it causes pruritus of the anus, from which it may be found projecting. This parasite is best treated by means of a cathartic, followed by a course of mineral tonics, and repeated rectal injections of sodium chloride solution, infusion of quassia or diluted creolin.
The cestodes or taeniae of the horse are insignificant in size and they produce no special symptoms. Three species—Anoplocephala perfoliata (26-28 mm. long), A. plicata (1½-8 cm.) and A. mamillana (1-3 cm.)—have been described. The first is found in the small intestine and caecum, rarely in the colon; the second occurs in the small intestine and stomach; the third in the small intestine. Generally a horse may be proved to be infested with tape-worm by finding some of the ripe segments or proglottides in the faeces. The best remedy is male fern extract with turpentine and linseed oil.
Gastrophilus equi, or the common bot-fly, is classed with the parasites on account of its larval form living as a parasite. The bot-fly deposits its eggs on the fore-arm, knee and shank of the horse at pasture. In twenty-four hours the ova are hatched and the embryo, crawling on the skin, causes itching, which induces the horse to nibble or lick the part, and in this way the embryo is carried by the tongue to the mouth and swallowed. In the stomach the embryo attaches itself to the mucous membrane, moults three times, increases in size and changes from a blood-red to a yellowish-brown
