Ten of 17 working dogs died on a roadtrip from Indiana to the Borderland on Monday.
The other seven are reportedly sick.
The dogs were bound for Customs and Border Protection k-9 training center at Fort Bliss.
Fort Bliss spokesman Maj. Joe Buccino told ABC-7 defective air conditioning is blamed for the deaths.
ABC-7 contacted the Indiana-based vendor, a kennel called Vohne Liche, to ask if they or a third party vendor was driving the dogs, but they have not responded to our inquiry.