Anoplocephala perfoliata
Anoplocephala perfoliata | |
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Beginning of patent period during the invasion of Anoplocephala perfoliata on a horse. Immature tapeworms (arrows) and tapeworms with gravid segments (arrow heads) | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Platyhelminthes |
Class: | Cestoda |
Order: | Cyclophyllidea |
Family: | Anoplocephalidae |
Genus: | Anoplocephala |
Species: | A. perfoliata
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Binomial name | |
Anoplocephala perfoliata (Goeze, 1782)
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Anoplocephala perfoliata is the most common intestinal tapeworm of horses, and an agent responsible for some cases of equine colic.[1]
Description
Between 8 and 25 centimeters long, Anoplocephala perfoliata is part of the order
Life cycle
This parasite follows the general Cyclophillidean life cycle diagrammed in Figure 1. These parasites prefer rich, grassy areas and are not often found in arid, desert climate areas such as Arizona. This life cycle is indirect, and requires an intermediate host, typically an
Pathology
A light infection within a horse will likely not exhibit any symptoms of infection.[2] However, a horse with a heavy infection can experience GI issues, weakness and anemia.[2] Immunocompromised horses (ex: extremely old and extremely young) can have only a light parasite load, but experience infection symptoms associated with extreme pathology.[3] The tapeworm perforating through the intestinal wall and ulcerating the mucosal layer of the stomach at the site of attachment has also been seen with this parasite leading to the intussusception.[2] Horses that have cases of infection Anoplocephala perfoliata are at an increased risk of suffering from colic while infected and after being treated.[2] An infected horse can also suffer from peritonitis (inflammation of the peritoneum) as well as secondary infections and abscesses at the site of attachment.[2] Impaction of the intestine is also a possible symptom.[3] In rare cases, the intestinal tract itself can twist and even rupture.[3]
Diagnosis
A fecal float can diagnose the presence of an infection however they may not always be present in a sample, especially if the host has a light infection.
Treatment
The typical
Praziquantel at a dose of 1 mg per kg is 89-100% effective at eliminating an infection of Anoplocephala perfoliata.[2] Ivermectin or Moxidectin in combination with Praziquantel are extremely effective against this parasite.[2]
No documentation of resistance to these treatments has been recorded yet.[3]
Prevention
Horses cannot develop immunity to these parasites, so prevention is a key step in maintaining their health.[3]
Interval deworming is a common practice among horse owners to prevent heavy parasite infections from occurring and is a safe, effective way to prevent an infection in a horse. The typical drug for this is Ivermectin.[2]
Pyrantel salts can be administered every day that horses are grazing.[2] The daily dose to eliminate A. perfoliata and A. magna is about 2.65 mg per kilogram.[2]
Lastly, rather than treating every day or sporadically, horses can be dewormed right before grazing season begins and after at the end of the season in areas where horses are not out year round due to climate.[2] This seems to be the most beneficial plan of prevention for horses as it can remove any parasites left over from the winter months and then after grazing season, eliminates the parasites they may have become infected with over the summer.[2]
For young horses that are just getting weaned off mother's milk, tapeworm treatment is highly recommended to prevent infection, as when infection occurs this early in life, it can put them at a high risk for ileocecal colic.[3]