Chronic kidney disease (CKD) is a common progressive disease in elderly cats and inappetence is frequently reported as a clinical sign. Mirtazapine is an appetite stimulant that a previous Winn study demonstrated it to be useful in the management of appetite and weight in cats with CKD. Since poor body condition is associated with a poor prognosis, maintaining nutrition is a key goal of medical management. The medication is currently available in pill form, which presents a problem for cats resistant to pill administration, and potentially interferes with the bond between owner and pet. The purpose of this study is to assess the efficacy of transdermal mirtazapine in stimulating appetite in cats suffering from inappetence associated with CKD.