Life cycle studies showed that third stage larvae of Chabertia ovina undergo an extensive histotropic phase in the wall of the small intestine prior to the third. Pathogenicity studies in sixteen 4-month-old Merino cross wethers maintained on a low plane of nutrition and given , and C. ovina larvae showed. Int J Parasitol. Dec;1(3) The pathogenic importance of Chabertia ovina (Fabricius, ) in experimentally infected sheep. Herd RP.
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It is found worldwide but is more frequent in regions with a temperate climate. These worms do not affect dogs and cats. The disease caused by Chabertia worms is called chabertiasis or chabertiosis.
Predilection site of chaberria Chabertia ovina is the large intestine.
The parasitic life cycle of Chabertia ovina (Fabricius, ) in sheep.
Chabertia ovina adults are 1 to 2 cm long, whereby females are larger than males. The worms have a tubular digestive system with two openings, the mouth and the anus.
Characteristic for these worms is a large cup-shaped mouth capsule, without teeth. They also have a nervous system but no excretory organs and no circulatory systemi. The female ovaries are large and the uteri end in an opening called the vulva.
Males have a rather large copulatory bursa with two long and thin spicules for attaching to the female during copulation. The eggs are ovoid, about 50×90 micrometers, have a thin shell and contain more than 16 cells Blastomeres.
Chabertia ovina has a direct life cyclei. Adult females lay eggs in the large intestine of the host that are shed with the feces. Once in the environment the eggs release the L1-larvae that complete development to infective L3-larvae in about 7 days.
The parasitic life cycle of Chabertia ovina (Fabricius, 1788) in sheep.
By moist weather these larvae can chabertiaa on pasture and remain infective for up chabrtia 10 months. Livestock becomes infected after ingesting infective larvae with pasture, but also indoors with contaminated hay. Immature larvae attach to the wall of the small intestine and feed voraciously on the tissues.
About a week later they detach and migrate to the cecum, where they complete development to adult worms, which move to the colon, their predilection site. There they attach to the wall with their ovnia capsule and females start laying eggs up to 10′ eggs daily! L4 larvae can become arrested dormant, hypobiotic in the tissues to survive the cold or the dry season.
In most regions Chabertia ovina is not the most harmful among the gastrointestinal worms that affect sheep and goatsbut worsens the damage caused by other species e.
Haemonchus spp, Ostertagia spp, etc. Adults and larvae do not suck blood but may ingest some if a blood vessel is damaged.
Nevertheless they harm the gut’s lining where they attach, whereby they often change their attachment site multiplying the lesions. These causes small but numerous local ulcers, sometimes also bleeding, which can be significant in case of massive infections. Seriously affected animals can show diarrhea mucous or hemorrhagicanemia, weight loss, and can even die.
In less severe cases they may loose weight and produce less wool. Chabertia ovina does not seem to be pathogenic for cattle. Since most infections are mixed with other gastrointestinal roundworms e. Haemonchus sppOstertagia sppTrichostrongylus sppetc. Diagnosis is based on the clinical signs and confirmed after detection of characteristic eggs in the feces.
Being quite resistant to adverse environmental conditions, Chabertia larvae can survive up to 10 months on pasture, which makes it quite difficult to reduce the populations.
Or they spend the winter as dormant larvae. This ensures re-infection of the pastures during the next spring. As a general rule, whatever reduces pasture contamination with infective larvae e. Such preventative measures are the same for all gastrointestinal roundworms and are explained in a specific article in this site click here. Livestock exposed to these worms often develop natural resistance progressively and may recover spontaneously.
Such resistant animals do not become sick if re-infected, but continue shedding eggs that contaminate their environment. Numerous broad spectrum anthelmintics are effective against adult worms and larvae, e. But not all of them are effective against arrested larvae of Chabertia ovina. Read the product label carefully to find it out. L evamisole and most macrocyclic lactones are usually also available as injectables.
In some countries e.
Chabertia ovina – Wikipedia
It is effective against Chabertia ovina adults and immature L4 larvae, but not against inhibited larvae. It is not approved for cattle or goats. Numerous commercial products contain mixtures of two or even more active ingredients of different chemical classes.
This is done to increase the chance that at least one active ingredient is effective against gastrointestinal worms that have become resistant, or to delay resistance development by those worms that chzbertia still susceptible.
Excepting slow-release bolusesmost wormers containing benzimidazoles e. This means that they have a short residual effector no residual effect at all. As a consequence treated animals are cured from worms but do not remain protected against new infections.
To ensure that they remain worm-free the animals have to be dewormed periodically, depending on the local epidemiological, ecological and climatic conditions. An exception to this are macrocyclic lactones e. Lvina are so far no true vaccines against Chabertia ovina.
To learn more about vaccines against parasites of livestock and pets c lick here. Biological control of Chabertia ovina i. Learn more about ovna control of worms.
You may be interested in an article in this site on medicinal plants against external and internal parasites. Cooperia sppHaemonchus sppOstertagia sppTrichostrongylus sppetc. This means that if an anthelmintic fails to achieve the expected efficacy against Chabertia ovinathere is a low risk that it is due to anthelmintic resistance.
I t is well known that many cases of product failure are due to incorrect use of a product, or to the use of an unsuited product, not to resistance. Learn more about parasite oovina and how it develops.
Ask your veterinary doctor! If available, follow more specific national or regional recommendations for Chabertia control. Control of Flies Biol. Control of Ticks Biol. Biology, prevention and control. Details Written by Ovia. Also in this site: