Immune-mediated haemolytic anaemia in dogs: diagnosis
6-year-old Cocker Spaniel with acute weakness, pale and icteric mucous membranes and dark urine.
| Parameter | Result | Reference |
|---|---|---|
| Haematocrit | 18% | 37–55 |
| MCV | 78 fL | 60–77 |
| Reticulocytes | 280,000/µL | < 60,000 |
| Blood smear | Numerous spherocytes | — |
| Saline agglutination | Positive | Negative |
What is the most likely diagnosis?
chevron_right Show answer and explanation
A. Immune-mediated haemolytic anaemia (IMHA)
Correct. Strongly regenerative anaemia with spherocytes, agglutination persisting after saline dilution and icterus is the classic picture of IMHA. Cocker Spaniels are predisposed.
B. Anaemia of chronic inflammatory disease
It is a mild to moderate, normocytic, non-regenerative anaemia. Here there are 280,000 reticulocytes/µL: the marrow is responding strongly.
C. Iron deficiency anaemia from chronic blood loss
Iron deficiency causes microcytosis and hypochromia, without spherocytes or icterus. Here MCV is raised because of the reticulocytes.
D. Bone marrow aplasia or hypoplasia
An aplastic marrow does not produce reticulocytes: the anaemia would be non-regenerative and probably accompanied by other cytopenias.
lightbulb Key takeaway
Distinguish agglutination from rouleaux with a saline test (1 drop of blood + 4 of saline). If agglutination persists, a Coombs test is not needed for the diagnosis. Always look for triggers (drugs, infections, neoplasia) and consider thromboprophylaxis.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.