Scientific name: Cyathostomum spp., Cylicostephanus spp., Cylicocyclus spp., Cylicodontophorus spp
Common name: Small Strongyles

Description: Small strongyles are bright red parasitic worms that range in size from 0.25 to 2.0 in. (1.3 to 5.1 cm) in length. There are over 40 species of small strongyles, 29 of which are found in the U.S. They live within the intestinal wall, potentially causing mild colic and intestinal ulcers. Small strongyles are much less harmful to horses than large strongyles because larval migration is limited to the intestinal wall. However, it is not uncommon for horses to have large numbers of small strongyles, which can adversely affect gut motility. Some species of small strongyles have developed a resistance to benzimidazole class of compounds. Several studies over several years have shown ZIMECTERIN to be highly effective at controlling small strongyles with no documented resistance.

Life cycle: Adult female worms lay eggs in the intestine of an infected horse. The eggs pass with manure and hatch into larvae. Infective larvae attach to grass and are eaten by other horses. Once ingested, larvae migrate along the intestinal wall for a period of 6 to 7 months. Eventually, they return to the large intestine as adults, where they feed and lay eggs.

Symptoms: Small strongyle infection can lead to chronic conditions of mild colic, weight loss, diarrhea and loss of appetite.

Click here to access detailed information in PDF format.