Page:Encyclopædia Britannica, Ninth Edition, v. 24.djvu/226

Rh 206 V E T V E T In the Pig- than in cattle. For a full description of its anatomy and develop ment, see TREMATODA, vol. xxiii. p. 535. Strongylus micrurus is the husk-producing worm of cattle. The common earthworm is the intermediate bearer. S. filaria, or the common lung strongyle of sheep, is distinguished from S. micrurus by having no papillae on its head. The males are 1 inch to 1 inch 2 lines long and the females nearly 3 inches. The development is unknown ; but Cobbold thought that in its larval form the creature infested snails, &c. The symptoms of its presence in the sheep are a dull expression, quickened breathing, fcetid breath, foaming at the mouth and nostrils, violent and spasmodic cough, loss of appetite, and emaciation. Of various specific remedies the most successful is a mixture of oil of turpentine, linseed oil, and sulphuric ether, administered two mornings in succession, followed by a third dose on the fourth morning. This causes coughing, and consequent freeing of the tubes of the larvae and mucus. Good results have been derived from inhalation of chlorine gas, &c., which acts in the same way. The intratracheal injection of oil of turpentine is said to be followed by favourable results. The system should be supported with as much good nourishing food as possible. S. rufescens, or gordian strongyle (males 5 to 6 inches long, females 6 to 7 inches), is very often associated with S. filaria. The principal Cestode of ruminants is Tsenia expansa, which, when fully mature, is more frequently found in sheep than in cattle. Its body consists of about one thousand segments, each more broad than long. It is the longest of all tape -worms, being (according to Cobbold) in sheep from 8 to 30 feet and in oxen from 40 to 100 feet in length. Its maximum width is f inch ; it is found in the large and small intestines. Cobbold thought its larval form was developed in the louse of the ox. The symptoms are emacia tion, with dysentery, and loss of appetite. Male fern ought to be given in doses according to the size of the animal. For a full account of the development of Cysticercus bovis, the beef measle, see TAPE-WORMS, vol. xxiii. pp. 50-52. 0. ovis is supposed by Cobbold to be the larval form of his so-called T. tenella of the human subject. Another bladder worm, found only in the mesentery of the sheep, is C. tenuicollis, the larval form of T. marginata of the dog. An other important hydatid of ruminants is Camurus ccrebralis, which gives rise to gid ; it is generally found in the brain of sheep, cattle, goats, deer, &c., and also in the soft structures of rabbits. It is the larval form of T. ccenurus of the dog. The symptoms of gid are these. The animal has a rotatory motion ; it does not graze freely ; there is paralysis on the opposite side to the vesicle ; the head is elevated or depressed if the hydatid is situated in the centre ; and the animal is easily frightened. Medical treatment is of no avail ; but the hydatid may be removed by a surgical operation. Trichocerihalus affinis, the common whip-worm, sometimes gives rise to severe symptoms in ruminants, particularly in sheep. The males and females are each about 2 inches long. The helminths of the pig, although not very detrimental to the animal itself, are nevertheless of great importance in respect to the Entozoa of the human subject, being the intermediary bearers of some dangerous human parasites in their immature state. Allusion must be made to Trichina spiralis (see PARASITISM, vol. xviii. p. 270). The development of this parasite requires about three weeks after being taken into the stomach, where the capsule is digested ; it then passes into the intestines of the pig, principally the duo denum, where it takes two days to become mature ; then after about a week the embryos leave the body of the female worm, and immedi ately commence penetrating the walls of the intestines in order to pass into some voluntary muscles. About fourteen days elapse from the time they begin their wandering. Each is generally enveloped in a capsule, but two or even four have been found in one capsule. The male is -jVth, the female ^th inch long, and the larvae ^yth to -jth inch. They have been known to live in their capsules from eighteen months to two years. Cysticercus celluloses is the larval form of Tsenia solium of man (see TAPE-WORMS, vol. xxiii. p. 52). &quot; Measly pork &quot; is caused by the presence in the tissues of the pig of this entozoon, which is bladder-like in form. It has also been discovered in the dog, ape, bear, rat, and deer. Other important parasites of the pig are Stephanurus dentatus, or crown-tailed strongyle, and Echinorhyn- chus gigns. This latter is the only thorn-headed or acanthocepha- lous worm infesting the domesticated animals (Cobbold). The commonest of all parasites infesting the dog is Ascaris mystax (males 2 to 3^ inches, females 3 to 8 inches long). It is also found In the in the cat and larger canines. The symptoms are wasting, voracity, dog. irregularity of bowels, short cough, and irritation at anus ; in the cat, more particularly, large quantities of mucus, with numerous parasites, are vomited. The treatment consists of the administra tion of castor oil, with santonine, according to the size of the animal. Filaria immitis, another Nematode, infests the heart of the dog, and its larvae circulate in the blood, giving rise to fits, which often end in death. Twnia serrata is a moderate-sized Cestode, from 2 to 3 feet in length ; it is found in about 10 per cent, of all English dogs, most frequently in sporting dogs, especially greyhounds and harriers, owing to their eating the intestines of rabbits, &c., in which the larval form (Cysticercus pisiformis) of this parasite dwells. It takes two months to pass through the first stage and one month to pass through the second when it is artificially produced, but much longer when produced naturally (Cobbold). T. ccenurus gives rise to gid in sheep, as previously stated. It is 18 to 24 inches long, and is principally seen in the small intestines. T. marginata is the largest Cestode infesting the dog. It varies in length from 5 to 8 feet, and is found in the small intestines of about 30 per cent, of dogs in Great Britain ; its larval form, C. tenuicollis, is found in the mesentery, &c. , of sheep. In the treatment of Cestodes extract of male fern has been found the most effectual remedy ; areca nut and a pill consisting of colocynth and jalap, varying according to the size, age, and condition of the dog, have also proved efficacious. Com paratively small doses of any vermifuge have often been found to give rise to violent symptoms, and all vermifuges if taken in large doses produce death ; too much care cannot, therefore, be exercised in administering vermifuges to young animals. Another order of parasites which cause numerous diseases of the Dennato- skin in the domesticated animals may be classed under two heads, zoa. -viz., animal parasites or Dcrmatozoa and vegetable parasites or Dermatophyta. The animal parasites are those which produce scab, itch, mange, &c., in all animals. This class may be again divided into three varieties, viz., Sarcoptes, which burrow in the skin ; Dermatodectes, which bite the skin ; and Symbiotes, which simply pierce the epidermis (Gerlach). All these parasites live on serous fluids, produced by the irritation which they excite. Either one or more of these varieties infest all our domesticated animals : all three varieties have been found on the horse and sheep, the last two on the ox, and one in the pig, dog, and cat respectively. The sarcoptic variety of the horse and dog is easily transmitted to man. To distinguish between the different varieties, it is only necessary to place a few fresh scales in the sun ; if Sarcoptes are present, they will soon be found on the under surface, whereas Dermatodectes are on the upper surface. Again, the Sarcoptes are isolated, whereas the Symbiotes and Dermatodectes live in clusters or colonies. Thirdly, the Symbiotes do not burrow, but merely bite the skin, and principally invade the limbs. An effectual cure for those which infest the horse is a mixture of sulphur, hellebore, oil of turpentine, whale oil, and carbolic acid, applied for three successive days, then washed off and applied again. For the dog a very useful remedy is made from creosote, olive oil, solution of potassium, and sulphur, also train oil and spirits of tar. The first is an almost sure cure for cats. A good remedy for destroying lice may be compounded from staphysagria powder, soft soap, and hot water, applied warm to the skin. Vegetable parasites are of two kinds, namely, Tinea tonsurans, Dermato or the common ringworm, seen in most of our domesticated animals, phyta. and Favus, or honeycomb ringworm. The latter is seldom seen. T. tonsurans is due to a cryptogamic parasite, Trlcopliylon, and is lodged in the interior of the roots of the hairs, which after a time lose their elasticity and break off, leaving the fungi in the form of a greyish white bran-like incrustation. In this they differ from Favus, which is yellow and covers the epidermis. It may affect any part of the body, but occurs principally on the head, face, neck, and hindquarters ; it is very prevalent amongst young cattle. Ringworm is very contagious, and may be communicated from one animal to another, and from animals to man. It mostly attacks badly-fed and ill-cared-for animals. The affected parts should be well washed with soft soap and warm water, removing as much as possible of the bran-like scales, and then with Stockholm tar oint ment, and finally with either iodine (in tincture or ointment) or carbolic acid (in solution or ointment). (G. FL.) VETO. By this expression (Lat. veto, &quot; I forbid &quot;) is understood in public law the constitutional right of the competent authority, or in republics of the whole people in their primary assembly, to protest against a legislative or administrative act, and to prevent wholly, or for the time being, the validation or execution of the same. It is generally stated that this right was called into existence in the Roman republic by the tribunicia potestas, because by this authority decisions of the senate, and of the consuls and other magistrates, could be declared in operative. Such a statement must, however, be qualified by reference to the facts that interdico, interdicimus were the expressions used, and, in general, that in ancient Rome every holder of a magistracy could check a negotiation set on foot by a colleague, his equal in rank, by his opposition and intervention. This was a consequence of the position