Page:The Zoologist, 4th series, vol 4 (1900).djvu/371

Rh also said to be found in the stomach. Although uncommon in this country, Tæniæ are often abundant in the Horses in Russia and Germany. Tænia perfoliata, the commonest species, infests the cæcum and small intestine, sometimes the colon. It is a small worm, seldom reaching more than two or three inches in length—Rudolphi records it as reaching 80 mm.; the head is provided with four suckers, and, like the other two species, is devoid of hooks; the proglottides are thick and short, and the colour creamy white.

Nematodes we find in all parts of the body. This group of worms, which contains so many parasites, is of much importance to those interested in Horses and Horse-breeding in all parts of the world, for they are often the cause of serious epizootic attacks, occasioning very considerable loss. These Round Worms are particularly plentiful in the intestines of the Horse, where perhaps they cause the gravest functional disturbances; but they also invade the kidneys, eyes, blood-vessels, serous membranes, skin, &c.In Europe our chief pests are intestinal in habit, often causing great mortality in foals. The following are those which are most prejudicial to the health of the host, and which may be considered general equine pests:—

Two species of so-called "Red Worms" are well known in the Horse, but observations made tend to show that we have evidently three species to deal with, for the common Small Red Worm, usually taken to be the S. tetracanthum of Diesing, does not agree with the detailed description of that species, which Mr. Theobald has observed only twice in England. He has therefore proposed provisionally the name rubrum for this Small Red Worm, as a distinct species from the one described by Diesing.

The Maw Worm (Oxyuris) is a very prevalent equine pest, but, as far as can be gathered, it only occasions slight functional disturbances in digestion, and violent burning and itching sensations in the rectum and around the anus. When present in large numbers the Maw Worms nevertheless cause emaciation, and cannot be otherwise than prejudicial to their host.

This is perhaps one of the best known worms in the Horse on account of its size, the female often reaching 14 in. in length, and the male from 6 to 10 in. It is a special parasite of Horses. In colour it is yellowish white and rigid; the oral region is restricted off from the body, and provided with three lips with teeth on their free margin. The ova are globular, and are produced by hundreds, and are passed out in the host's excreta; numbers also come away with the female worms that are frequently passed by the Horse.