Skrjabinema is a genus of roundworms that belongs to the group of pinworms and has sheep, goats and American camelids as main hosts.

They are found worldwide. The most relevant species for domestic animals are Skrjabinema ovis, Skrjabinema caprae and Skrjabinema alata.

Adult Skrjabinema spp (A) and anterior end (B). © J. Kaufmann / Birkhäuser Verlag

The disease caused by Skrjabinema worms is called skrjabinemosis.

Are animals infected with Skrjabinema worms contagious for humans?

NO. The reason is that these worms are not human parasites.

You can find additional information in this site on the general biology of parasitic worms and/or roundworms.

Final location of Skrjabinema worms

Predilection site of adult Skrjabinema worms is the large intestine (cecum).

Anatomy of Skrjabinema worms

Egg of Skrjabinema spp. Picture from

Skrjabinema worms are rather small (<10 mm long), whereby females are twice as long as males. As other roundworms, their body is covered with a cuticle, which is flexible but rather tough.

The worms have no external signs of segmentation. They have a tubular digestive system with two openings. Characteristic for these worms is that the esophagus ends in a large spherical bulb.

They also have a nervous system but no excretory organs and no circulatory system, i.e. neither a heart nor blood vessels. Males have only one chitinous spicule for attaching to the female during copulation.

The eggs are about 35x55 micrometers, contain a larva and have an oval but asymmetric shape, one side being flat, which makes the easy distinguishable from eggs of Strongyloides papillosus.

Life cycle and biology of Skrjabinema worms

Skrjabinema worms have a direct life cycle, i.e. there are no intermediate hosts involved. Adult females lay embryonated eggs around the anus of the hosts.

These eggs fall to the ground. Other hosts ingest them and the larvae hatch in the small intestine and move to the large intestine where they complete development to adults and begin to lay eggs.

The prepatent period (time between infection and first eggs shed) is about 25 days.

Harm caused by Skrjabinema infections, symptoms and diagnosis

Skrjabinema is considered as non-pathogenic for sheep and goats. However, it could contribute to worsen the effects of other more harmful gastrointestinal worms. It can also be mistaken for Oesophagostomum worms.

Diagnosis can be done after detection of eggs in the feces. However, due to their particular egg laying behavior eggs are often very scarce or not at all present in the feces of infected animals.

Prevention and control of Skrjabinema infections

Preventative measures are the same for all gastrointestinal roundworms and are explained in a specific article in this site (click here). Considering the little harm caused by these worms it is usually advisable to orient such measures to the control of other gastrointestinal worms (e.g. Haemonchus spp, Ostertagia spp, Trichostrongylus spp, etc.) more harmful than Skrjabinema worms.

Virtually no anthelmintic is approved for the control of Skrjabinema worms. Based on a cost-benefit basis it is usually not recommended to use anthelmintics only to control Skrjabinema worms.

There are so far no true vaccines against Skrjabinemaworms. To learn more about vaccines against parasites of livestock and pets click here.

Biological control of Skrjabinema worms (i.e. using its natural enemies) is so far not feasible.

You may be interested in an article in this site on medicinal plants against external and internal parasites.

Resistance of Skrjabinema worms to anthelmintics

So far there are no reports on resistance of Skrjabinema worms to anthelmintics.

This means that if an anthelmintic fails to achieve the expected efficacy, chance is very high that either the product was unsuited for the control of Skrjabinema worms, or it was used incorrectly.

Ask your veterinary doctor! If available, follow more specific national or regional recommendations for Skrjabinema control.