A second K9 police dog has died after being stuck in a car during sweltering temperatures.

The tragedy happened when the dog, named Aron, who had been working as a K9 police dog for two years, was left behind with the engine running and the air conditioning working in Houston, Texas, USA.

But the police cruiser’s air conditioning unit failed when the engine cut out unexpectedly, causing the temperatures in the car to quickly rise and causing the four-year-old dog severe difficulties.

The dog was still alive when the handler returned and rushed the distressed pet to a vet, but it was too late to save him.

A police spokesman said that the dog handler was being treated for shock and that a K9 is like family to a police officer.

In a statement, Houston Police Department said that all cars are fitted with a system that sounds the horn, activates cooling fans and roll down the windows if the vehicle shuts down. However, for some reason, this failsafe device was not triggered on this occasion.

Aron and his handler worked on duty in the specialist bomb-sniffing unit operating at the local George Bush International Airport.

The tragedy follows on from another incident involving a K9 in Georgia when Chase, a dog assigned to the Cork County Police Department, was left in a car in sunny weather when the air conditioning unit also failed.