Dyspnoea during transfusion in a cat with chronic anaemia
15-year-old cat with chronic kidney disease (IRIS stage 3), chronic non-regenerative anaemia with a haematocrit of 11%, normovolaemic and with a grade II/VI murmur. She receives type A whole blood with a compatible crossmatch, 20 mL/kg over 2 hours. At the end she develops tachypnoea, crackles and jugular distension.
| Parameter | Result | Reference |
|---|---|---|
| Systolic pressure | 185 mmHg (previously 150) | 120–160 |
| Heart rate | 230 bpm (previously 190) | 140–220 |
| Temperature | 38.4 °C (unchanged) | 38.0–39.2 |
| Plasma | No haemolysis | — |
| Focused ultrasound | Diffuse B-lines; LA/Ao 1.7 (previously 1.4) | < 1.5 |
What is the most likely diagnosis?
chevron_right Show answer and explanation
A. Acute haemolytic reaction due to antibodies against the Mik antigen
A compatible crossmatch detects this incompatibility, and there is no haemolysis in the plasma and no fever.
B. Transfusion-associated circulatory overload (TACO)
Correct. Hypertension, tachycardia, jugular distension, B-lines and an atrium that enlarges during the transfusion indicate volume overload. Cats with chronic anaemia are normovolaemic and in a high-output state, often with heart disease or CKD. Stop the transfusion, give oxygen and furosemide.
C. Transfusion-related acute lung injury (TRALI)
TRALI is a non-cardiogenic oedema: it usually causes hypotension and fever, without jugular distension or left atrial enlargement.
D. Anaphylactic reaction to donor plasma proteins
Anaphylaxis causes hypotension, and in cats respiratory and gastrointestinal signs, but not hypertension or atrial enlargement.
lightbulb Key takeaway
In a cat with normovolaemic chronic anaemia, transfuse packed red cells rather than whole blood, at a slow rate, and monitor respiratory rate and blood pressure every 15–30 minutes. Consider echocardiography before transfusing if there is a murmur or gallop.
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Updated: November 1, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.