When designing a catio for senior cats or cats with mobility issues, prioritize easy access and safety. Install ramps or gentle slopes instead of stairs to facilitate movement. Ensure that resting areas are low to the ground and easily reachable. Provide soft, supportive bedding to accommodate joint issues. Avoid placing items that require jumping or climbing. Incorporate non-slip surfaces to prevent falls. Ensure that the catio is protected from extreme weather and includes shaded, warm spots for comfort. Regularly monitor and adapt the space to meet the evolving needs of senior or mobility-challenged cats.