There are two types of infections that can develop depending on the route of infection. Although there are multiple species of cestodes, this paper will focus on three particular species that cause human disease: Taenia solium (pork tapeworm), Taenia saginata (beef tapeworm), and Diphyllobothrium (fish tapeworm). They represent a small, but avoidable, risk in certain types of colic.Cestodes are flat, parasitic, hermaphroditic tapeworms with complex life cycles that infect animals, including humans. The role of tapeworms in equine colic should be kept in perspective. Generally, treatments directed against tapeworms should be given every six months, with treatment in the fall and again in late spring. perfoliata – the common tapeworm – is better understood, it is difficult to decide when to provide horses with appropriate anti-tapeworm drugs. Its presence can lead to decreased intestinal motility and colic. The tapeworm can cause severe damage inside the horse’s intestinal tract. Until recently, few studies had been done of the damage caused by tapeworms. It is in this small area of the horse’s intestinal tract that changes attributable to tapeworms are found. The equine tapeworm usually congregates around the ileocaecal valve in the intestinal tract, at the junction between the large and small intestines. There appears to be little seasonal variation in the number of horses infected with tapeworms or in the magnitude of infection. They can begin shedding segments full of eggs in 6-10 weeks. Larvae then develop within the primary host – the horse – to mature tapeworms. Inadvertent ingestion of mites containing infective larvae occurs as horses graze, and it can result in tapeworm infection. Inside the mite, the tapeworm egg undergoes cellular division and development to become a larva. This mite is found in very large numbers on pastures and often even in hay and straw. perfoliata is the free-living oribatid mite. This means it requires an intermediate host in order to develop. The tapeworm is different from many other parasites because it has an indirect life cycle. Sometimes, however, tapeworm specimens can be found in the feces of infected horses after they have been treated with drugs active against these parasites. Most veterinary practices and labs aren’t equipped to do these tests, so, in many cases, the diagnosis is missed. More sophisticated tests are needed to visualize tapeworm eggs. They don’t float well in the testing medium, so they are often missed in routine fecal egg-count analysis. They occur in very small numbers and often in packets rather than individual eggs. One textbook describes unthriftiness and anemia as consequences of heavy infestation, but moderate infections may go unnoticed.Īnother factor making diagnosis difficult is the nature of tapeworm eggs. Most infections have no symptoms, but cause subclinical damage that may be present for some time before causing visible disease. Tapeworm Diagnosisĭiagnosing tapeworm infection is difficult. Nutrients are absorbed through the parasite’s cuticle. perfoliata is equipped with four suckers with which the parasite can secure itself to the mucosa of its host. The size of mature worms varies from three to eight centimeters – tapeworms smaller than this are either immature worms or P. perfoliata is a short, yellow/green tapeworm with a triangular body. perfoliata to be the most common tapeworm in the horse. Anoplocephala perfoliata, Anoplocephala magna and Paranoplocephala mamillana. Three species of tapeworms are known to infect the horse. Add to this several studies showing tapeworm infection rates as high as 81.5 percent, and an interesting story emerges about a parasite that was previously considered harmless. Recent studies, however, have defined this parasite as a significant risk factor for spasmodic colic and impactions at the terminal end of the small intestine. Infections usually went undetected because of the difficulties of fecal egg examinations and because no clearly defined clinical symptoms were associated with tapeworms. The equine tapeworm was considered for many years to be an incidental finding in the intestinal tracts of horses at postmortem examination and rarely associated with clinical disease. The natural infection is hard to diagnose in the living animal, and no successful experimental infections have been reported. Much uncertainty surrounds the significance of tapeworm infections in horses.
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