While there was nothing to stop people travelling in a car with an unrestrained dog, it made sense to "buckle up" a dog to stop it becoming a flying missile in the event of a crash.
"It's common sense. Buckle up your child. Buckle up your dog."
Ms Pine said there was a variety of safety harnesses on the market.
Unsecured dogs could also prove a distraction to the driver, she said.
Ms Pine was approached for comment after a recent Otago Daily Times observation of drivers pulled up at a set of Princes St lights when, in the space of about 15 minutes, three cars containing unrestrained dogs were seen.
One driver was seen kissing a dog sitting on her lap, another was supporting a dog which was standing on the front seat, with its front paws on the dashboard, and the third had two small dogs sitting on the parcel tray.
Ms Pine said dogs travelling with their heads out the window could also run the risk of eye infections or damage as they were subjected to dust, "bugs in the air" and debris.
A dog behaviourist, who did not wish to be named, said when a dog was travelling with its head out the window there was also the risk it would get a broken neck if "you hit the brakes".
Dogs should either be buckled in, or contained behind a grille in the back of a vehicle, but if there were no other options they should be on the floor in the front on the passenger's side, with the lead shut in the door so they could not go anywhere.
Dogs could also be at risk if they leapt out of the car into traffic on arrival at their destination.
In her training classes, the behaviourist taught dog owners not to let their dogs leave the car without a command.
Dunedin police emergency response group manager Inspector Alastair Dickie said it did not appear unrestrained dogs in vehicles were "up there" as a cause of accidents, but there was potential for that.
If it was considered an unrestrained dog had caused an accident, a charge of careless use of a motor vehicle could result, but he was not aware of instances of this.
People needed to use common sense.
Ms Pine said it was hard to know how many dogs might be injured as a result of not being transported safely.
Dogs travelling on the back of utility vehicles and trucks were legally required to be secured, either in a container on the deck or by a lead.
However, if the lead was too long the dog could get dragged.
Some vet clinics spoken to by the ODT said most of the dogs they saw from vehicle-related injuries were as a result of being run over, rather than from trips with their owners.
Balclutha vet Dr Suzanne Craig said she did not see many dogs as a result of falls from vehicle decks, but those she had treated had injuries ranging from minor pad abrasions to large amounts of skin stripped from their hind quarters.
She also knew of cases where dogs had choked and died.
One animal she had treated a couple of years ago had been dragged about 1.5km before the driver realised.
That dog required six weeks' treatment but was restored to "perfect health", she said.
The harm caused was not intentional.
Often, people did not realise the lead was too long.
Ideally, if the dog was tied on the back of a vehicle, rather than in a secure cage, it should be secured in the middle of the vehicle with a lead that would not allow it to get its hind quarters off the deck when it was straining against the lead.
"Once you get the hind quarters over, there is a risk of strangling."
Dr Craig said in the past she had also seen quite a few cases where dogs had broken toes when their paws caught on the bars at the back of four-wheeler motorcycles used on farms.
She had not seen any recently so hoped this indicated increased awareness of this risk.
If dogs travelling in cars were secured, they did not become a weighty projectile if the driver had to brake suddenly, and were also more settled, unlike the "yo-yo dog" which could be seen bouncing from one side of the car to the other.
Because it was buckled in from a young age, her own dog now associated being strapped in with the excitement of the journey.
