Tapeworm-Colic Link Discovered

At long last, evidence supporting a link between the equine tapeworm Anoplocephala perfoliata and colic in horses was identified by a group of Italian researchers from the Universita degli Studi di Perugia.

Earlier thought held that A. perfoliata did not actually cause disease in horses, but that the parasites were simply an incidental finding in horses' guts.

According to the researchers, "since the 1980s, an increasing prevalence of case reports describing a close association between specific causes of equine colic, such as impaction, intestinal rupture, intussusception, volvulus, and large intestine obstructions and severe A. perfoliata infestations has increased the interest in the pathological effects of this parasite."

The researchers therefore sought to investigate changes in the equine gut associated with tapeworms at the junction between the last part of the small intestine (ileum) and the first part of the large intestine (cecum), referred to as the ileocecal junction. The team randomly selected 31 horses (11 parasite-free and 20 horses with spontaneous A. perfoliata infections) and evaluated the ileocecal junctions.

A significant relationship between parasitic burden and microscopic grade of damage to multiple layers of the intestine (mucosa and submucosa) was noted. In addition, hypertrophy (abnormal enlargement) of circular muscular layer of the intestine was obvious. Finally, injury to intestinal nervous elements, referred to as the enteric nervous system, was noted in horses with moderate to high parasitism.

According to the study authors, "our results might support a close correlation between colic and A. perfoliata infestation in the horse."

They also noted that the enteric nervous system lesions suggest that the use of "well-timed diagnostic tests and orderly preventative deworming programs" are indicated in horses with moderate infestations to "prevent or minimize the risk of colic caused by A. perfoliata."

The study, "Pathological changes caused by Anoplocephala perfoliata in the equine ileocecal junction," was published in the journal Veterinary Research Communications in May 2010.

The abstract is available on PubMed.

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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