Vetdle

Think. Diagnose. Play.

Vetdle Archive

Archive Case #106: Bovine Photosensitisation

Cattle veterinary case - Medium - June 17, 2026

Clinical Clues

  1. Several light-skinned cattle develop painful crusting lesions after a spell of bright sunny weather.
  2. The worst affected areas are on the teats, muzzle, and white facial skin.
  3. The animals are restless and seek shade during the day.
  4. The skin becomes red, swollen, and then peels.
  5. The syndrome is linked to accumulation of photodynamic compounds in susceptible skin.
  6. Photosensitisation in cattle commonly affects unpigmented areas exposed to sunlight.

Diagnosis

Bovine Photosensitisation

This case is most consistent with Bovine Photosensitisation because the cattle have painful sun-exposed lesions limited to lightly pigmented skin. The most important clues are the shade-seeking behavior and lesion distribution, which make a simple contact dermatitis less likely.

Learning review

Review the case evidence

Use the paired clues to explain how the evidence in this cattle case supports the provided diagnosis, Bovine Photosensitisation, then compare your reasoning with the case explanation.

Evidence checkpoints

Clues 1-2

  1. Clue 1: Several light-skinned cattle develop painful crusting lesions after a spell of bright sunny weather.
  2. Clue 2: The worst affected areas are on the teats, muzzle, and white facial skin.

Clues 3-4

  1. Clue 3: The animals are restless and seek shade during the day.
  2. Clue 4: The skin becomes red, swollen, and then peels.

Clues 5-6

  1. Clue 5: The syndrome is linked to accumulation of photodynamic compounds in susceptible skin.
  2. Clue 6: Photosensitisation in cattle commonly affects unpigmented areas exposed to sunlight.

Self-review prompts

  1. After clues 1-2, what evidence from this cattle case shaped your initial interpretation?
  2. When you compare clues 3-4 with clues 1-2, what changed in your reasoning about Bovine Photosensitisation?
  3. How do clues 5-6 align with the case explanation for Bovine Photosensitisation?

Educational Use

Vetdle archive cases are educational veterinary games for diagnostic reasoning practice. They do not provide veterinary advice, diagnosis, treatment, or professional medical guidance.