(CNN) A dog being flown by Delta Air Lines from Phoenix to Newark, New Jersey, died during the trip Wednesday, according to a spokeswoman for the airline.

The owners, Michael Dellegrazie and his girlfriend, were traveling from Phoenix to New York and decided to put their 8-year-old Pomeranian, Alejandro, on a plane so they could pick the dog up at the Newark airport.

During the layover in Detroit, Alejandro was held in a cargo facility.

"There was a stop in Detroit at 6 a.m. Alejandro was checked on. He was alive. Then between 8 a.m. and 8:30 a.m. he was checked on again and he was dead," said Dellegrazie's attorney, Evan Oshan.

A Delta official said the dog was discovered with vomit and fluids in the cage.

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