Central nervous system disorders after renal transplantation in cats

Objective - This study describes the incidence and severity of postoperative central nervous system (pCNS) disorders in feline renal transplant recipients. Study Design - A retrospective study based on the medical records of cats that received renal allografts from 1987 to 1996. Animals or Sample Population - Fifty-seven client-owned cats received renal allografts for the treatment of renal failure. Methods - The frequency, duration, severity, and treatment of episodes of pCNS disorders were recorded from the medical records. Results - Twelve (21%) of 57 cats had pCNS disorders 1 hour to 5 days after the surgical procedure. Seven cats survived; four had single or multiple seizure episodes, and two had seizure episodes or disorientation followed by a period of coma. One cat became temporarily ataxic and blind after restraint for venipuncture. Five cats died; all had episodes of disorientation or seizures, or both, that progressed to a nonrecoverable comatose state, respiratory arrest or cardiac arrest, or both. There were no significant differences between the two groups in preoperative serum creatinine, blood urea nitrogen, or cholesterol levels, and intraoperative blood pressure measurements. There were no significant differences in the postoperative serum glucose levels, electrolytes levels, or osmolality between the two groups. The cats with pCNS disorders had a mean preoperative trough cyclosporine A (CyA) whole blood level of 429 ng/mL; cats without pCNS disorders had a significantly (P = .0116) higher mean preoperative trough CyA whole blood level of 736 ng/mL. Conclusion - Central nervous system disorders are a common and often fatal complication of renal transplantation in cats. Clinical Relevance - Recognition of pCNS disorders, and possible causes, will help develop hypotheses to investigate the problem.