Dreamcatcher Alpacas
Alpaca health · Parasites

Nematodirus in Alpacas

Updated 2026-10-02By the Dreamcatcher Alpacas editorial team6 peer-reviewed references
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Urgent — contact your vet today

Early treatment makes a big difference. Don't wait more than a day.

A small-intestine worm that can cause sudden, severe diarrhea in crias, sometimes before eggs appear in feces.

Category
Parasites
Urgency
Urgent

Signs & symptoms

  • Sudden profuse diarrhea in crias
  • Rapid dehydration
  • Weakness, sunken eyes
  • Death in untreated crias

Related symptom guides: Alpaca Diarrhea (Loose Stool).

What causes it?

Nematodirus species (including N. battus) have eggs that survive cold and hatch in large numbers when conditions are right, exposing young animals to a sudden heavy dose.

Risk factors

  • Crias grazing pastures used by last year's crias
  • Spring weather after cold winters

How vets diagnose it

Fecal flotation (distinctive large eggs), history and clinical signs.

Treatment

Prompt vet-directed deworming and fluid therapy.

Do not wait to see if it improves. Camelids hide illness, and by the time signs are obvious the problem is often advanced. Call your veterinarian.

Prevention

  • Avoid grazing this year's crias on last year's cria paddocks
  • Fecal-test crias from 6-8 weeks of age

Background

Trichstrongyloidea is a superfamily of nematodes under the order Strongylida.From Wikipedia — “Trichostrongyloidea”, licensed under CC BY-SA 4.0.

Research & references

PubMed lists 28 peer-reviewed papers on this topic in camelids. The most relevant include:

  1. New parasitological findings for pre-Hispanic camelids. Taglioretti V, Fugassa MH, Rindel D et al. Parasitology, 2017. PubMed 28679457 · DOI · cited 7×
  2. Apex Predators, Rockshelters, and Zoonoses in the Patagonian Holocene. Fugassa MH, Petrigh RS The Journal of parasitology, 2017. PubMed 28783428 · DOI · cited 3×
  3. Parasitic diversity found in coprolites of camelids during the Holocene. Taglioretti V, Fugassa MH, Sardella NH Parasitology research, 2015. PubMed 25859925 · DOI · cited 11×
  4. Presentation, Clinical Pathology Abnormalities, and Identification of Gastrointestinal Parasites in Camels (Camelus bactrianus and Camelus dromedarius) Presenting to Two North American Veterinary Teaching Hospitals. A Retrospective Study: 1980-2020. Locklear TR, Videla R, Breuer RM et al. Frontiers in veterinary science, 2021. PubMed 33829053 · DOI · Free full textOpen access · cited 16×
  5. Gut parasites of alpacas (Vicugna pacos) raised in Poland. Szopieray K, Templin J, Osten-Sacken N et al. Journal of helminthology, 2024. PubMed 39665131 · DOI · cited 3×
  6. Postmortem diagnoses in South American camelids and factors influencing diagnostic rate in the Upper Midwest USA, 2009-2019. Clarke LL, Breuer RM Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc, 2022. PubMed 35394374 · DOI · cited 12×

Frequently asked questions

What is nematodirus in alpacas?
A small-intestine worm that can cause sudden, severe diarrhea in crias, sometimes before eggs appear in feces.
What are the signs of nematodirus?
Sudden profuse diarrhea in crias, rapid dehydration, weakness, sunken eyes and death in untreated crias.
How do you prevent nematodirus?
Avoid grazing this year's crias on last year's cria paddocks. Fecal-test crias from 6-8 weeks of age.
Is nematodirus an emergency?
Urgent — contact your vet today. Early treatment makes a big difference. Don't wait more than a day.

This page is educational and does not replace advice from a veterinarian who has examined your animals. Camelid medicine uses many drugs “extra-label”, so dosing must come from your vet. In an emergency, call your vet first. Read our disclaimer · How we write and review content.