Horse palisade worm
| Horse palisade worm | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Strongylus vulgaris | ||||||||||||
| ( Looss , 1900) |
Palisade worms, also blood worms and strongyles, are endoparasites that live in the large intestines of horses, donkeys, mules and zebras. They belong to the roundworms and are divided according to size into the parasite group Small Strongyles ( Cyathostominen ) and Large Strongyles ( Strongylus vulgaris , Str. Equinus , Str. Edentatus ).
About 50 species of palisade worms are known in horses. Palisade worms sometimes develop outdoors and are ingested orally by the host as larva without an intermediate host.
features
The male reaches a size of 1.9 cm, the female a size of up to 2.5 cm.
Life cycle
The infectious larva is ingested with food. In the appendix and large intestine, the larvae then drill into the lower intestinal mucosa and develop into the adult animal in the intestinal arteries. Representatives of the large strongyles (e.g. S. vulgaris ) migrate into further intestines before they return to the intestines. After this development, they migrate back into the intestines. There eggs are formed again, which are then excreted with the feces . There the larva develops up to its third juvenile stage.
Harmful effect
Small strongyles
A mass infestation of the larvae in the intestinal arteries leads to vasodilation. It can lead to blood clots there. Since the horse palisade worm sucks blood, this can also cause damage. However, there is usually only minor inflammation.
The larvae encapsulate during the winter months, after which there can be mass infestation (simultaneous emigration, so-called larval cyathostominosis ) with colic, diarrhea and emaciation - serious mucosal erosions occur in the large and appendix.
Large strongyles
The large strongyles ('especially S. vulgaris ) migrate through the body as larvae and cause considerable tissue damage.
Treatment and control
Oral anthelmintics ( anthelmintics ) show different effectiveness. Some substances cannot fight the encapsulated stage , the parasites have already developed resistance to others ( benzimidazoles ).
Attempts are made to limit the transmission through hygiene (removing excrement, changing pasture), but wild animals are also carriers. Horses have very different infestation intensities, most are carriers, but certain and especially older horses shed significantly more eggs than others. Attempts are made to reduce the development of resistance by only giving animals worming agents that exceed a certain egg concentration in the feces (e.g. 200 per gram).
literature
- A. Kaestner: Textbook of special zoology. Gustav Fischer Verlag, Jena 1993, ISBN 3-334-00339-6 , p. 516ff.
- ↑ http://www.pferdeschuppen.de/palisadenwurm_strongyliden.htm Nadine B. Taubenheim: Palisade worms (blood worms, strongylids) , online article, accessed on October 23, 2018
- ↑ a b c d e http://www.vetmed.fu-berlin.de/einrichtungen/institute/we13/dienstleistungs/Informationen/Wurminfektion-beim-Pferd.pdf G. v. Samson-Himmelstjerna: Worm infections in horses: Current problems and recommendations for sustainable and health-preserving control , in Tierärztl. Umschau 71 (2016), pages 247 ... 256, accessed on Oct. 22, 2018
- ↑ a b https://www.barnboox.de/pferdewissen/gesundheit/vorsorge/wurminfektion-beim-pferd-endoparasiten-arten/ Meike Bölts: Worm infection in horses: Endoparasite species , accessed on October 22, 2018
- ↑ a b http://www.uni-giessen.de/fbz/fb10/institute_klinikum/institute/parasitologie/informationen/entwurmung Christian Bauer: Selective deworming in horses , information sheet for veterinarians and horse owners (2017) of the Department of Veterinary Medicine at the University of Gießen , accessed on Oct. 22, 2018
- ↑ http://www.entwurmungpferd.de/zeitgemaesse-selektiven-entwurmung/ A. Becher: Selective worming , accessed on October 22, 2018