Dreamcatcher Alpacas
Alpaca health · Infectious diseases

Listeriosis in Alpacas

Updated 2026-10-02By the Dreamcatcher Alpacas editorial team6 peer-reviewed references
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Emergency — call your vet now

This condition can kill within hours. Get veterinary help immediately.

A bacterial infection of the brainstem usually linked to spoiled silage or haylage, causing circling and facial paralysis.

Category
Infectious diseases
Urgency
Emergency
Spreads to people
Yes — see below

Signs & symptoms

  • Circling, leaning, head tilt
  • Drooping ear, eyelid or lip on one side
  • Drooling and difficulty eating
  • Fever and depression

Related symptom guides: Head Tilt or Circling, Fever (High Temperature).

What causes it?

Listeria monocytogenes multiplies in poorly fermented silage, haylage, wet hay and soil-contaminated feed.

Risk factors

  • Feeding silage or haylage
  • Moldy, soil-contaminated feed

How vets diagnose it

Clinical signs, feed history and spinal fluid testing.

Treatment

Urgent high-dose antibiotic therapy and supportive care by a vet.

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 silage/haylage or use only excellent-quality product
  • Discard spoiled feed

Can people catch it?

Listeria can infect people, particularly pregnant women. Use gloves.

Background

Listeriosis is a bacterial infection most commonly caused by Listeria monocytogenes, although L. ivanovii and L. grayi have been reported in certain cases. Listeriosis can cause severe illness, including severe sepsis, meningitis, or encephalitis, sometimes resulting in lifelong harm and even death. Those at risk of severe illness are the elderly, fetuses, newborns, and those who are immunocompromised. In pregnant women, it may cause stillbirth or spontaneous abortion, and preterm birth is common. Listeriosis may cause mild, self-limiting gastroenteritis and fever in anyone.From Wikipedia — “Listeriosis”, licensed under CC BY-SA 4.0.

Research & references

PubMed lists 15 peer-reviewed papers on this topic in camelids. The most relevant include:

  1. Identification and characterization of species-specific nanobodies for the detection of Listeria monocytogenes in milk. Tu Z, Chen Q, Li Y et al. Analytical biochemistry, 2016. PubMed 26456330 · DOI · cited 33×
  2. Septicemia and meningoencephalitis caused by Listeria monocytogenes in two neonatal llamas. Hawkins IK, Ilha M, Anis E et al. Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc, 2017. PubMed 28677403 · DOI · cited 2×
  3. Neurologic diseases in llamas and alpacas. Whitehead CE, Bedenice D The Veterinary clinics of North America. Food animal practice, 2009. PubMed 19460647 · DOI · cited 28×
  4. High affinity anti-Internalin B VHH antibody fragments isolated from naturally and artificially immunized repertoires. Gene RW, Kumaran J, Aroche C et al. Journal of immunological methods, 2015. PubMed 25450000 · DOI · cited 15×
  5. Anti-InlA single-domain antibodies that inhibit the cell invasion of Listeria monocytogenes. Yamazaki T, Nagatoishi S, Yamawaki T et al. The Journal of biological chemistry, 2023. PubMed 37716701 · DOI · Free full textOpen access · cited 6×
  6. Listeria associated mural and valvular endocarditis in an alpaca. McLane MJ, Schlipf JW Jr, Margiocco ML et al. Journal of veterinary cardiology : the official journal of the European Society of Veterinary Cardiology, 2008. PubMed 19036668 · DOI · cited 3×

Frequently asked questions

What is listeriosis in alpacas?
A bacterial infection of the brainstem usually linked to spoiled silage or haylage, causing circling and facial paralysis.
What are the signs of listeriosis?
Circling, leaning, head tilt, drooping ear, eyelid or lip on one side, drooling and difficulty eating and fever and depression.
How do you prevent listeriosis?
Avoid silage/haylage or use only excellent-quality product. Discard spoiled feed.
Is listeriosis an emergency?
Emergency — call your vet now. This condition can kill within hours. Get veterinary help immediately.
Can people catch it from alpacas?
Listeria can infect people, particularly pregnant women. Use gloves.

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.