According to Amazon's policies, there are some restrictions on selling pet urinal pads. These restrictions include, but are not limited to, the following:

1. Standards: Pet urinal pads must meet the standards and requirements set by Amazon to ensure the quality and safety of the product.

2. Packaging and labeling: The packaging and labeling of pet urinal pads must be clear and provide necessary information, such as product size, purpose, material, etc.

3. Advertising and descriptions: Advertising and descriptions of pet urinal pads must be true and accurate, and must not mislead consumers or provide false or exaggerated product information.

4. Product classification: Pet urinal pads must be correctly classified in the pet products category.

5. Product compliance: Pet urinal pads must comply with relevant laws and regulations, such as consumer product safety standards. Please note that the above restrictions are only general guidelines, and specific restrictions and requirements may vary by region and country. To ensure compliance with Amazon's sales policies, please read and comply with the regulations of the Amazon platform in detail before selling pet urinal pads. At the same time, you can also contact Amazon's customer service team to get more accurate information and guidance.