High demand for trendy breeds like pugs, dachshunds and French bulldogs helps fuel the "sickening trade".
'Backstreet breeders' will face jail for selling puppies under eight weeks old.
More than 100 puppies have been seized by Irish police during an attempt to smuggle them out of the country.
Six puppies have been found in a wheelie bin shelter in Glasgow, where they were left in a box amid freezing temperatures.
The six-week-old male and female crossbreeds are now being cared for by Scottish SPCA staff at the Glasgow Animal Rescue and Rehoming Centre in Cardonald
Read more about the abandoned puppies on the STV website.