Plasma cell pododermatitis is a condition in which the paw pads become swollen, discolored, cracked, and occasionally ulcerated, due to infiltration by plasma cells. As the paw pad lesions are commonly considered characteristic of FPP, and often considered localized skin disease, diagnostics for systemic health are uncommonly performed. A subset of young feline patients presenting clinically for evaluation of kidney disease have either historical or current evidence of FPP, several of which were confirmed to be immune complex mediated glomerulonephritis (ICGN) when comprehensive renal pathologic assessment was performed. ICGN is a serious and potentially life-threatening disease that requires immunosuppressive therapy. The purpose of this study is to further investigate the link between these two diseases, determine over a two-year period how frequently cats with pododermatitis develop kidney disease, and monitor response to therapy. Your cat will participate in this study for a duration of 2 years, during which time they will be evaluated by a veterinarian and have blood and urine samples collected every 6 months (if they do not have evidence of kidney disease) or every 3 months (if they have evidence of kidney disease). If at any point during the 6 month rechecks your cat has new evidence of kidney disease, re-check appointments will move to every 3 months. These appointments may occur either at your regular veterinary office or a specialty veterinary practice. Your cat will receive complimentary lab work for two years as described and if applicable, the availability of medical consultation about management of kidney disease from a board-certified specialist in feline chronic kidney disease.

Clinical signs of nausea, vomiting, and dysrexia (abnormal appetite behaviors) are common in feline patients with chronic kidney disease (CKD). Weight loss and loss of lean body mass in these patients is likely attributable to changes in appetite as well as processes such as cachexia (weight loss due to an underlying illness) and sarcopenia (loss of muscle mass and function associated with aging). Poor appetite is perceived as an important aspect of quality of life and can cause significant emotional distress to caregivers. A better understanding of the effect of management of inappetence in CKD on quality of life will improve our ability to help feline patients with CKD. Therefore, the purpose of this study is to assess the effect of appetite stimulation on quality of life in cats with CKD.What does enrolling my pet in this clinical trial involve? At the time of screening, your cat will receive a physical examination and comprehensive laboratory screening to confirm stage of CKD and exclude other newly diagnosed conditions. They will then be randomized to receive either mirtazapine transdermal ointment or placebo. Both are an ointment that will be administered transdermally to the inner surface of the ear flap once daily. Cats will be randomized into one of two groups (mirtazapine or placebo) and then switch to the other group after two weeks. We will follow up via phone one-week following enrollment to address any questions or concerns. You will bring your cat back for two recheck visits (Week 2 and Week 4) for a physical exam, blood and urine collection, and blood pressure measurement. From the time of initial screening to the completion of the study, you will be asked to complete the online Vetmetrica Quality of Life survey* - a validated instrument to assess quality of life in cats - on a weekly basis, as well as a daily log of appetite.Client Compensation:There is no cost to you for enrolling your cat in this study. The exams and diagnostics performed at enrollment, Weeks 2 and 4, and the cost of the mirtazapine transdermal ointment medication used, are covered by the study alone. In the unlikely situation that an adverse event that requires treatment occurs as a result of taking part in this study, the cost of treatment will be covered by the study. 

Evidence exists to suggest that aging of the kidney may contribute to the onset and progression of chronic kidney disease (CKD). Rapamycin is a drug that is a potential modulator of the aging process and additionally may decrease the formation of fibrosis (scarring) in the kidney. A feline formulation of the drug is available and the purpose of this study is to assess the potential benefit of the drug in cats with CKD. Your cat will receive complimentary assessment and management of disease by a board-certified specialist in feline CKD as well as standard of care laboratory monitoring regardless of study group. Cats randomized to the study drug group will possibility benefit from this therapy. There is no cost to you for enrolling your cat in this study. You will receive complimentary physical examination for your cat and diagnostic testing. You will also receive $25 per visit incentive.