He was also shocked to find the valuable dog isn't microchipped. However, working dogs aren't required to be microchipped.
"If it was the tools of my trade I'd certainly be looking for it," he said. "If she had a microchip we'd be able to return her to owner straight away."
The dog ranger urges all pet owners to ensure not only their dogs were microchipped in case of an accident or being lost, but to make sure the microchipping number and owner's details are lodged with the council against the dog's registration or on a national database.
Veterinarians aren't responsible for doing this - the dog owner is.
It costs $20 to have a dog microchipped through Masterton District Council or about $80 if a vet inserts the chip.
"It's disturbing dogs aren't microchipped," said Mr Falk.
Meanwhile, the wandering dog is making quite an impression.
"She has a lovely nature. She's a really lovely dog."
If you think the dog is yours, call Hannah at Masterton council on (06) 370 6300.