Fluid overload in the dog with anuric kidney injury
6-year-old Labrador with anuric acute kidney injury after eating grapes, on intravenous fluids for 48 hours. Its weight has risen from 30 to 33.5 kg, and it has serous nasal discharge, chemosis, tachypnoea and pulmonary crackles.
What is the most appropriate course of action?
chevron_right Show answer and explanation
A. Continue fluids and add high-dose furosemide, because without fluids the kidney will not recover
In established anuria furosemide rarely works, and continuing fluids worsens the oedema. The kidney does not recover by being 'flushed' with more volume.
B. Switch to a synthetic colloid to maintain volume without causing oedema
A colloid is still volume and does not remove the excess. Moreover, hydroxyethyl starches have been associated with kidney injury in critically ill people.
C. Switch the fluids to the subcutaneous route so they are absorbed more slowly
Subcutaneous fluid still ends up in the vascular and interstitial spaces: it does not correct the overload and makes it worse.
D. Stop the fluids, give oxygen and refer urgently for haemodialysis or ultrafiltration
Correct. Weight gain > 10% with signs of oedema is severe overload, associated with higher mortality. In an anuric patient, the only way to remove that volume is extracorporeal (or peritoneal dialysis).
lightbulb Key takeaway
In oliguric or anuric kidney injury, once the patient is rehydrated, fluids should match losses: insensible losses (about 20 mL/kg/day) plus measured urine and vomit. Weigh the patient at least twice daily: a gain of more than 5–10% over the rehydrated weight is a warning sign.
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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.