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- Dogs have been a staple on seafaring vessels for thousands of years.
- The canine companions were first given official US Navy duties during World War II.
- Scot Christenson, author of 'Dogs in the Navy,' spoke to Business Insider about their history.
Man's best friend will follow him anywhere — even across the vast oceans.
Dogs had long been a staple on seafaring vessels even before the US Navy made them part of the official crew during World War II.
Decades later, many dogs continue to serve in military.