The deaths come as the RSPCA says that complaints about illegal puppy farming have increased dramatically over the past 10 years and that 87% of current puppy trade calls are about animals purchased online.

In a Reddit question-and-answer forum, Edwards said Piper took about a year and a half of "passive training" - plus three days or so of acclimation to the goggles - to be ready for his chasing and patrolling duties.