Vetdle

Think. Diagnose. Play.

Vetdle Archive

Archive Case #48: Ovine Haemonchosis

Sheep veterinary case - Medium - April 20, 2026

Clinical Clues

  1. A mob of lambs is investigated for poor growth and increasing weakness during a warm grazing season.
  2. One affected lamb has obvious submandibular oedema.
  3. Mucous membranes are very pale despite minimal diarrhoea.
  4. Blood tests confirm marked anaemia and reduced plasma protein concentrations.
  5. Faecal testing finds many strongyle-type eggs, which cannot be identified to genus by their appearance alone.
  6. This pattern supports ovine haemonchosis, commonly caused by the blood-feeding abomasal nematode Haemonchus contortus.

Diagnosis

Ovine Haemonchosis

Marked anaemia, protein loss, bottle jaw and poor growth with little diarrhoea are most consistent with ovine haemonchosis. Routine strongyle eggs support gastrointestinal nematodiasis but do not by themselves identify Haemonchus. Larval differentiation or a targeted assay can strengthen identification; other parasites and nonparasitic causes of anaemia remain differentials. Remember: Routine strongyle egg counts do not identify the genus; anaemia and bottle jaw with little diarrhoea raise suspicion of haemonchosis.

Learning review

Review the case evidence

Use the paired clues to explain how the evidence in this sheep case supports the provided diagnosis, Ovine Haemonchosis, then compare your reasoning with the case explanation.

Evidence checkpoints

Clues 1-2

  1. Clue 1: A mob of lambs is investigated for poor growth and increasing weakness during a warm grazing season.
  2. Clue 2: One affected lamb has obvious submandibular oedema.

Clues 3-4

  1. Clue 3: Mucous membranes are very pale despite minimal diarrhoea.
  2. Clue 4: Blood tests confirm marked anaemia and reduced plasma protein concentrations.

Clues 5-6

  1. Clue 5: Faecal testing finds many strongyle-type eggs, which cannot be identified to genus by their appearance alone.
  2. Clue 6: This pattern supports ovine haemonchosis, commonly caused by the blood-feeding abomasal nematode Haemonchus contortus.

Self-review prompts

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

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.