Acute Kidney Injury Refractory to Conventional Treatment in a Cat: The Reversal Impact of Peritoneal Dialysis

Abstract

Background: Acute kidney injury (AKI) in cats is associated with various causes, including poisoning, infectious diseases, ischemia, and tumors. Clinically, it presents with anorexia, vomiting, diarrhea, prostration, and dehydration. Laboratory findings often include azotemia, metabolic acidosis, and hyperkalemia. Standard treatment focuses on fluid therapy and correction of electrolyte disturbances. Peritoneal dialysis (PD) is indicated in cases of anuria, severe azotemia, or poisoning with dialyzable toxins. Although AKI is widely recognized in cats, there are few reports of PD used as a therapeutic tool in these cases. The present report aims to address this gap.
Case: This report describes the case of a cat presented with anorexia, emesis, and diarrhea, possibly associated with the ingestion of a plant, although this was not clearly explained in the anamnesis. On physical examination, the patient was dehydrated (12%), jaundiced, and hypotensive (90 mmHg). Laboratory tests showed azotemia (creatinine 11.7 mg/dL), metabolic acidosis (pH 7.159; bicarbonate 11.1 mmol/L), hyperkalemia (potassium 7.40 mmol/L), direct hyperbilirubinemia (25 mg/dL), and increased liver enzyme activity. Ultrasound showed bilateral kidney, liver, and spleen enlargement. All the findings reported were in line with a diagnosis of intoxication, AKI, and cholangiohepatitis. Therapy with antiemetics, antioxidants, and correction of dehydration and systolic blood pressure was started, followed by dialysis. Twelve PD cycles were carried out using Dianeal PD-2® with 1.5% glucose. After the initial sessions, the patient became alert and normorexic. By the end of therapy, azotemia (creatinine 2.07 mg/dL), metabolic acidosis (pH 7.286; bicarbonate 13.8 mmol/L) were corrected and serum potassium concentration (4.06 mmol/L) was normalized. The patient remained clinically healthy with
normal laboratory values one year later.
Discussion: Owing to the multiple etiologies of AKI, the identification of the exact cause remains undetermined in approximately 1/3 of patients, as in this case. More than 50% of cases involve nephrotoxic substances, and because the anamnesis reported possible interaction with the aloe vera plant, there probably is a correlation between this and kidney damage. There is a lack of studies proving the nephrotoxicity of Aloe vera in cats. In humans and rodents, the association between substances in this plant and impaired kidney function has already been reported. PD was an effective treatment, with the patient surviving for >365 days, similar to other reports. The positive response included rapid correction of acidosis and hyperkalemia and a reduction in creatinine levels within 15 days. Therapeutic success is related to the reversible nature of the disease and the early onset of polyuria. Despite the good results, peritonitis is a common complication of PD, particularly with prolonged treatment. In the case reported herein, the patient developed peritonitis after 15 days with the abdominal drain, and the isolated bacteria were different from those usually described. This reinforces the importance of culture and antibiogram in the management of infections. It is concluded that PD was an effective and  affordable alternative for the management of AKI in this cat. Although it involves an invasive technique, it requires fewer resources than hemodialysis and can be routinely performed by a trained team. The literature is still scarce on the subject, which highlights the importance of reports like this one to build clinical knowledge.

Keywords: cats, AKI, azotemia, dialysis, nephrotoxicity.