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Case report: management of acute renal failure in a gravid bitch by peritoneal dialysis

An 18 month old female pregnant Springer Spaniel was referred with a history of acute severe azotaemia and oliguria. On physical examination, she was bright, and in good bodily condition. Initial blood results revealed a urea of 53.0 mmol/l and a creatinine of 896 umol/l. Potassium was 3.9, suggesting the urine production was sufficient to prevent hyperkalaemia. Urinalysis showed a specific gravity of 1014, glucose ++++ and protein ++, consistent with glomerular and proximal tubular dysfunction. Ultrasonography showed a relatively normal appearance to the kidneys, with no sign of thrombosis, hydronephrosis or nephrolithiasis. A titre for Leptospirosis was negative.

Under anaesthesia, a peritoneal dialysis catheter was placed through a keyhole incision. The first day of dialysis produced a poor recovery rate of dialysate fluid, so on the second day, a repeat anaesthetic and caudal laparotomy was carried out. The catheter had become completely entrapped by omentum, so a partial omentectomy was performed. From this point on, the catheter worked well. Aggressive dialysis was instituted, with 12 exchange cycles per day of hypertonic dialysate. Medications included metoclopramide and ondansetron, ranitidine, clavulanate-amoxycillin and cyproheptadine. It was also decided to abort the puppies in order to reduce the stress on renal function. Cabergoline and dinoprost were given, but cabergoline seemed to worsen vomiting, so this was discontinued and dinoprost alone was used. After 7 days of treatment, a single large puppy was passed. Ultrasonography and radiography confirmed no pups remained behind.

Over the course of the first week of therapy, urea levels fell steadily (see figure below). Creatinine climbed slightly initially, stabilised, and then fell consistently. Dialysis was discontinued after 6 days, at which point urea was down to 26.3 and creatinine to 663. The dog then entered the polyuric phase of the disease.

She remained extremely bright in herself throughout, apart from one day where she became quite dull in herself. Intensifying the fluid therapy regime improved her demeanour and vital parameters rapidly. Frequency of vomiting reduced and then stopped, but she remained anorexic. Under light general anaesthesia, the dialysis catheter was removed and an oesophagostomy tube placed to assist with feeding.

After 2 days of tube feeding, the dog began to eat spontaneously. Intravenous fluid therapy was discontinued, but biochemical and clinical parameters suggested that despite a reasonable fluid intake, there was a net fluid loss. An indwelling subcutaneous catheter was implanted under sedation.

She was discharged 13 days after admission, and the owners found subcutaneous fluid administration straightforward and well tolerated. They are very pleased with the dog’s progress. She is bright, putting on weight and eating well.

Often in acute renal failure, the injury to the nephrons is sublethal, allowing recovery. This dog may return to full normal renal function over time, or she may suffer from chronic renal failure. Peritoneal dialysis is useful for the management of acute renal failure, as well as certain other conditions such as acute poisonings with dialyzable toxins (eg ethylene glycol) and overhydration. If instituted early in the course of the disease it can often improve the prognosis significantly.