Senator Ensign's training as a veterinarian has motivated his animal advocacy as a legislator. One of only two veterinarians in Congress, Ensign is working at the federal level to stop the neglect and mistreatment of animals. His Captive Wildlife Safety Act, signed into law by President Bush on December 19, 2003, protects exotic animals by preventing people from keeping them as pets. More recently, the Animal Fighting Prohibition Enforcement Act, which was originally authored by Ensign in 2002, was signed into law by President Bush on May 3, 2007. This legislation will help stop animal fighting by making the transportation of animals across state lines for the purpose of fighting a felony under federal law.

Ensign earned his Doctorate of Veterinary Medicine from Colorado State University in 1985. He immediately began practicing veterinary medicine and opened the first 24-hour animal hospital in Las Vegas. For Ensign, it was very rewarding to help people by helping their pets.

Although Ensign continues to advocate for the protection of animals in the United States Senate, he encourages people who love animals to communicate within their communities the importance of treating animals well.