Vetdle

Think. Diagnose. Play.

Vetdle Archive

Archive Case #212: Bovine Leukosis

Cattle veterinary case - Medium - October 1, 2026

Clinical Clues

  1. On a North American dairy farm, a seven-year-old cow steadily loses condition and produces less milk.
  2. Several firm swellings are found where superficial lymph nodes are normally examined.
  3. Rectal examination also identifies enlarged internal lymph nodes, indicating a multicentric process.
  4. A node aspirate contains large atypical lymphoid cells rather than a mixed reactive population.
  5. Biopsy confirms a malignant lymphoid tumour involving the node.
  6. BLV testing is positive. In this adult cow with confirmed multicentric lymphoma, the combined findings support the enzootic, virus-associated form of bovine leukosis.

Diagnosis

Bovine Leukosis

Tumour tissue establishes lymphoma, while the adult presentation and BLV result support enzootic bovine leukosis. A positive BLV test alone would only establish infection; many infected cattle never develop tumours. Remember: Separate evidence of viral infection from evidence of cancer—you need to interpret both.

Learning review

Review the case evidence

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

Evidence checkpoints

Clues 1-2

  1. Clue 1: On a North American dairy farm, a seven-year-old cow steadily loses condition and produces less milk.
  2. Clue 2: Several firm swellings are found where superficial lymph nodes are normally examined.

Clues 3-4

  1. Clue 3: Rectal examination also identifies enlarged internal lymph nodes, indicating a multicentric process.
  2. Clue 4: A node aspirate contains large atypical lymphoid cells rather than a mixed reactive population.

Clues 5-6

  1. Clue 5: Biopsy confirms a malignant lymphoid tumour involving the node.
  2. Clue 6: BLV testing is positive. In this adult cow with confirmed multicentric lymphoma, the combined findings support the enzootic, virus-associated form of bovine leukosis.

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 Leukosis?
  3. How do clues 5-6 align with the case explanation for Bovine Leukosis?

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.