As pets age, the number of dogs and cats experience mobility issues or paralysis due to joint degeneration. Many female owners hesitate to care for medium- to large-sized elderly dogs because of limited physical strength. Currently, single-function assistive devices—such as wheelchairs or carts—are relatively simple but cannot provide both care and emergency transport. To address this, the multifunctional pet cart design combines four functions into one device: a cart, stretcher, transport frame