Greyhound Protection Act of 2021 This bill modifies the federal criminal statute commonly known as the Wire Act. Currently, the Wire Act contains four prohibitions on the use of a wire transmission facility (e.g., the telephone or internet) for certain gambling activities. All four prohibitions apply to sports gambling. However, there have been conflicting interpretations of the applicability of the prohibitions to nonsports gambling (e.g., state lotteries). This bill amends the Wire Act to expressly state that the statute does not authorize the use of wire communications to gamble on commercial greyhound racing or permit the transport of animals for commercial dog racing or related activities.