Scratching as a result of skin problems could also be missed by owners.
Often pooches refrain from itching in front of their owners, Ms Caldwell said.
However, when "they're probably a little bit bored, there's no one to play with, then they start to scratch."
Nathan Lawrence, chief executive of Heyrex, the company that manufactures the devices, said they could help identify possible health problems. Research shows an animal's activity level is linked to how it feels and whether or not it is sick, he said.
Monitoring this over a prolonged period of time helps owners identify problems their pets may be having.
One Kapiti Coast owner found its dog needed treatment with a soothing aromatic remedy because "it just went absolutely mad" every time they returned home, Mr Lawrence said. Use of the Heyrex device revealed the dog was not doing anything during the day. After treatment, its moods evened out.
Anxious owners who disliked leaving their four-legged friends could also find the tracking device helpful.
One Wellington resident often took their dog to work because they found it too hard to be apart from him, he said. The owner was also reluctant to leave the pet at daycare. "We put a Heyrex unit on the dog and the dog's activity levels were actually heightened when he was at daycare. The owner could actually see that it was happier at the daycare than it was sitting at work."
Dogs recovering from surgery were also being fitted with the devices, Mr Lawrence said. A research unit at a North American veterinary surgery found the collar sensors useful in the immediate post-operative period. Between 15 to 20 per cent of dogs at the surgery were coming back with worn stitches, Mr Lawrence said.
Tracking revealed whether they were running around or staying inside as required - which often impacted on their recovery period.
He said cat-lovers could soon have access to a similar monitoring product, with a feline-friendly version expected to hit stores later this year.
