Diamond Farrier USA - 9” pad shears This is the best tool for trimming hoof pads that I have found.  They grip the pad to avoid movement and the easily slice through rubber, plastic and leather pads.

• Easily cuts and shapes all hoof pad materials such as leather, hard plastic and soft plastic
• Teeth on cutting surface grip material to prevent slippage while cutting
• Spring loaded handle for easy, 1-handed operation
• Locking mechanism on base of handle for storage
• German made from high quality steel