A protein called Mab 4B12 was found in boar sperm that also exists in dogs. This protein may affect boar sperm's ability to fertilize eggs in a lab setting. When tested on dog sperm, Mab 4B12 only stained the acrosome of active sperm, not inactive or reacted sperm. This suggests Mab 4B12 plays a role in binding dog sperm to egg cells. The results hint that Mab 4B12 could be used to prevent dog fertilization.