How long is too long for a pet to be in a car?

Gale, a border collie like the one shown above, survived nine days in the trunk of a car. See more pet pictures.
Doug Pensinger/­Getty Images

­October 2007 was a rough month for Gale, a border collie from Yorkshire, England. For more than a week, Gale went missing from her humans' farm. While residents in her hometown of Fylingthorpe searched for her, Gale was 245 miles down the isle in London -- hidden behind a tool box in the trunk of a local handyman's Vauxhall hatchback.

An airplane flying overhead startled Gale into taking refuge in the car's trunk. She went unnoticed by the car's owner, who left the farm where Gale lives for a weeklong trip to London. When the man returned to Fylingthorpe, he opened his trunk and discovered the dog lying motionless but alive. The border collie had survived nine days trapped in the trunk of a car [source: Daily Mail].

­By all measures, Gale should have been dead by the time she was found. Dogs can go for days and possibly weeks without food, but dehydration can begin to set in after 12 hours without w­ater [source: DEFRA]. The veterinarian who examined the lucky dog reasoned that condensation or rain must have entered the trunk, giving Gale just enough hydration to survive.

Gale was certainly a fortunate pup, and her harrowing tale of survival raises a question -- just how long is too long for a pet to be in a car at one time? This might not be much of an issue when you're running a few quick errands around town with your pet in tow, but there are some factors you should consider if you two decide to take that cross-country road trip. Find out what they are on the next page.