Those most commonly infesting the horse are the pin-worms or Ascarides. They are a small, round worm, pointed at both ends and from one to two inches long. They infest the large . intestines and rectum.

The next variety most common is the large round, or lumbricoid worm; the male may grow to twelve and the female to fifteen inches in length. They are mostly found in the intestines.

Symptoms. - There is generally a whitish-yellow deposit around the anus and the worms are occasionally seen in the manure.

Treatment. - A drachm of sulphate of iron given twice a day for a week then followed by a purgative is generally effective. A pint of raw oil and one ounce of turpentine given on an empty stomach will often dislodge them. Wood ashes mixed equally with salt and given daily will often answer the purpose. In treating for pin-worms the rectum should be injected twice a week with turpentine one part, and oil four parts.