Thousands of puppies are being illegally smuggled into the UK to meet demand at Christmas, a dog welfare charity has warned.
Nearly 100 puppies were seized at the border in a single week, the Dogs Trust said, which called the clampdown the "tip of the iceberg".
Demand for trendy breeds including pugs, dachshunds and French bulldogs fuels the "sickening trade", which can earn bootleg breeders tens of thousands of pounds.
Animals with behavioural and health problems are among those trafficked into the country in "shocking conditions" - many from central and eastern Europe, the charity said.
Last year, some 275,876 dogs travelled to Great Britain - more than treble the recorded number in 2011.
Dogs Trust veterinary director Paula Boyden said: "Buying an illegally imported puppy could potentially cost well-meaning but unsuspecting families thousands of pounds in quarantine and vet bills and emotional heartache for the family if the puppy falls ill or worse, dies."
The trust revealed that in one case, seven cane corso pups were found with infected wounds after having their ears and tails illegally cropped and docked with scissors and vodka.
It has compiled advice to help people avoid purchasing illegal puppies:
- Ask to see the mother and pup together, visit the new pup more than once and get paperwork before taking it home.
- Report suspicious sellers and take new puppies to their own vet for a health check as soon as possible.
- Do not meet anywhere that is not the pup's home, or buy from anyone who can supply various breeds on demand.
- Do not buy a puppy that looks too small or underweight, or feel pressured into buying.
The charity also highlighted concerns over a "shocking new trend" of smuggling heavily pregnant bitches into the UK to give birth.
Ms Boyden added: "We continue to be astounded at the lengths these deceptive breeders and dealers will go to in order to illegally import puppies to make huge profits with complete disregard for their wellbeing."
The maximum sentence for illegal importers is just three months. The charity is calling for an increase in penalties under the Non-Commercial Movement of Pet Animals (Amendment) Order 2011.
A spokesman for the Department for Environment, Food and Rural Affairs said: "We are cracking down on animal trafficking with one of the toughest pet border checking regimes in the world.
"Every pet dog travelling to the UK has both microchips and passports checked to make sure they are properly vaccinated and old enough to travel."