Cyclosporine A (CsA) is an immune-modulating medication. In veterinary medicine, CsA has been classically used as an immunosuppressive agent in kidney transplantation in cats. More recently, CsA has been reported to be effective for the management of several skin diseases, including allergic skin diseases. Allergy is a chronic, frustrating disease to manage, with few effective treatments available. Although steroids are an effective therapy for allergy in cats, side effects are common. A recent study reported CsA as an effective alternative to prednisolone in cats with allergic skin disease. Absorption of CsA is variable when given by mouth, making monitoring strategies difficult to implement. Additionally, for clients with cats that are difficult to medicate, giving medications by mouth for several weeks or longer, which is often the case with cyclosporine treatment, can be a problem leading to poor compliance and treatment failure. CsA injected under the skin may allow more steady blood concentrations, facilitating monitoring and dose adjustment. In addition, because of the small volume needed, this type of administration is expected to be well tolerated in cats. The objective of this study is to determine blood levels of CsA after subcutaneous administration. It is anticipated that subcutaneous administration will result in more predictable blood cyclosporine concentrations, reduce side effects, and decrease the need for expensive monitoring.