Australians now have a preference for smaller pedigree dogs with shorter, wider heads like pugs and bulldogs, according to trends in canine ownership.
Researchers from the University of Sydney analysed 180 breeds from registration statistics of the Australian National Kennel Council between 1986 and 2013.
The results have been published in the journal Canine Genetics and Epidemiology today.
They looked at demand for Australian purebred dogs of varying characteristics such as height, size and head shape and were put into four groups -- small, medium, large and giant.
Of those studied, there were 54 small breeds (less than 10kg), 62 medium (10-25kg), 42 large (25-40kg) and 22 giant (40kg and over) registered over that time.
Over that period, the registration of small and medium breeds increased by 4.2 percent and 5.3 percent respectively, relative to large breeds and 10 percent and 12.1 percent compared to giant breeds.
Lead researchers Kendy Teng says the trend from the 28 years of data showed a move toward smaller dogs every year from 1986.
They suggest the trend reflects a shift in people's lifestyles where they see dogs for companionship rather than specific jobs like hunting or guarding which tend to be filled by larger canines.
It could also be because of smaller living spaces or even fashion choices.
Between 1995 and 2010, many first-home buyers in Australia bought flats or apartments rather than houses, meaning potential owners wouldn't have had enough space for a big dog.
Whatever the reasons may be, the information will be helpful to veterinarians who are concerned about brachycephalic dogs which have shorter, wider heads, because of a number of medical conditions they can suffer from.
These include breathing difficulties, skin and eye infections and digestive problems.
In New Zealand, brachycephalic breeds are number four of the top five dog breeds considered by veterinarians to be unsuitable for continued breeding due to compromised health and welfare.
"We expect to see vets in Australia treating more dogs with the conditions described," Ms Teng says.
It's a similar story in the US and UK, where in recent years, bulldogs, boxers and pugs have become increasingly popular.
Between 2004 and 2013, the number of UK kennel club registrations for pugs and bulldogs have grown significantly.
There were 1675 pugs registered in 2004 compared to 8017 in 2013. During the same period, the numbers of French bulldogs from 350 to 6990.
In the US, the number of bulldogs and French bulldogs increased by 69 percent and 476 percent respectively in the past decade.
However, the authors note that while their results are accurate based on the Australian kennel club, it might not be truly representative of either the purebred or general dog population.