Dreamcatcher Alpacas
Alpaca health · Skin & fleece

Photosensitization & Sunburn in Alpacas

Updated 2026-10-02By the Dreamcatcher Alpacas editorial team6 peer-reviewed references
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Book a vet visit soon

Not usually an emergency, but it needs a diagnosis and a plan.

Sunburn-like damage on lightly pigmented skin caused by toxic plants or liver damage, or by sun on freshly shorn pink skin.

Category
Skin & fleece
Urgency
Book a vet visit soon

Signs & symptoms

  • Red, swollen, peeling skin on face, ears and legs
  • Itching and seeking shade
  • Eye irritation

Related symptom guides: Fleece Loss & Itching, Crusty Nose, Eyes or Ears.

What causes it?

Primary photosensitization (St. John's wort, buckwheat) or secondary to liver disease (pyrrolizidine alkaloid plants, lantana).

Risk factors

  • Toxic plants in pasture or hay
  • Close shearing in strong sun

How vets diagnose it

History, plant identification and liver function blood tests.

Treatment

Shade, removal from the plant source, wound care and treatment of liver disease.

Prevention

  • Remove St. John's wort and ragwort
  • Leave 1/2 in (1 cm) of fleece when shearing in very sunny areas

Background

Photosensitivity is an abnormal skin reaction to direct sunlight exposure. It is unrelated to a sunburn. These reactions are due to photosensitization, the accumulation of photosensitive compounds beneath the skin. In some cases, the photodynamic substances come from ingested plants or drugs, after being metabolized or not. In other cases, the photodynamic substances may be produced in the body itself due to inborn errors in pigment metabolism, especially those involving the heme synthesis. Photosensitivity reactions are usually seen in herbivorous or omnivorous animals, though such reactions are known among carnivores.From Wikipedia — “Photosensitivity in animals”, licensed under CC BY-SA 4.0.

Research & references

PubMed lists 11 peer-reviewed papers on this topic in camelids. The most relevant include:

  1. Llama dermatology. Rosychuk RA The Veterinary clinics of North America. Food animal practice, 1994. PubMed 7953956 · DOI · cited 12×
  2. Applications of nanobodies in brain diseases. Zheng F, Pang Y, Li L et al. Frontiers in immunology, 2022. PubMed 36426363 · DOI · Free full textOpen access · cited 56×
  3. Nanobodies and Nanobody-Based Human Heavy Chain Antibodies As Antitumor Therapeutics. Bannas P, Hambach J, Koch-Nolte F Frontiers in immunology, 2017. PubMed 29213270 · DOI · Free full textOpen access · cited 471×
  4. Self-Assembling VHH-Elastin-Like Peptides for Photodynamic Nanomedicine. Pille J, van Lith SA, van Hest JC et al. Biomacromolecules, 2017. PubMed 28269985 · DOI · Free full textOpen access · cited 38×
  5. Nanobody-Based Immunosensor Detection Enhanced by Photocatalytic-Electrochemical Redox Cycling. Trashin S, Morales-Yánez F, Thiruvottriyur Shanmugam S et al. Analytical chemistry, 2021. PubMed 34585567 · DOI · cited 10×
  6. Advances in Nanobody-Based Platforms for Precision Cancer Diagnosis and Therapy. Yuan Y, Zhuoga C, Zeng C et al. Polymer science & technology (Washington, D.C.), 2025. PubMed 42256247 · DOI · Free full textOpen access · cited 4×

Frequently asked questions

What is photosensitization & Sunburn in alpacas?
Sunburn-like damage on lightly pigmented skin caused by toxic plants or liver damage, or by sun on freshly shorn pink skin.
What are the signs of photosensitization & Sunburn?
Red, swollen, peeling skin on face, ears and legs, itching and seeking shade and eye irritation.
How do you prevent photosensitization & Sunburn?
Remove St. John's wort and ragwort. Leave 1/2 in (1 cm) of fleece when shearing in very sunny areas.
Is photosensitization & Sunburn an emergency?
Book a vet visit soon. Not usually an emergency, but it needs a diagnosis and a plan.

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.