Signalment: Four healthy adult mix breed dogs, weighing 30.0–40.5 kg, age 1–8 years.

History: The four dogs were presented on the same day after ingestion of 17 g of a maleic acid containing descaling agent accidentally mixed with food.

Diagnostic investigation: All four dogs underwent clinical and laboratory investigation and abdominal ultrasound. Creatinine values were increased (282–1502 µmol/l) on day 4. Glucosuria and decreased urine specific gravity was detected in urine analysis. The abdominal ultrasound showed enlarged, hyperechoic kidneys.

Therapy: All four dogs were treated as out-patients hospitalized at day 4. Treatment consisted of intravenous lactated Ringer´s, furosemide, metamizole, omeprazole, sucralfate, ranitidine and maropitant. After 2 days creatinine values decreased in two dogs. Two dogs did not respond to treatment. Creatinine increased to 1467 and 1723 µmol/l at day 6. One of these dogs was referred for hemodialysis at day 6, the other at day 8 in a worse clinical condition. Intermittent hemodialysis was performed with a Fresenius 4008 machine, pediatric tubing and a FX 60 dialyzer at day 7, 8, 9, 11 and 15 for the first and at day 8 and 9 for the second dog. Heparin was used for systemic anticoagulation. Conventionally treated dogs were discharged at day 16 with creatinine values in the reference range. The dog referred at day 6 was discharged at day 22 with a creatinine of 179 µmol/l. The dog referred at day 8 was euthanized at day 9 due to sepsis and worsening of the clinical situation on owner’s request. At 2, 4 and 6 months after maleic acid ingestion creatinine of all surviving dogs was within the reference range.

Discussion: Maleic acid led to acute kidney injury (AKI) in all four exposed dogs. Two dogs could be managed conservatively. In two dogs, dialysis was mandatory to control uremia. The AKI due to maleic acid intoxication is of good prognosis if uremia can be controlled either conventionally or by dialysis.