56 puppies were discovered at Dublin Port on Thursday night, in the second seizure this week.
The Dublin Society for Prevention of Cruelty to animals has taken the puppies into care, after they were seized following a joint operation by the police and customs unit.
Police believe they animals were being sent to Britain from puppy farms in Ireland.
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A 46-year-old man was arrested on the scene and taken to Store Street Garda Station. He was later released without charge.
Last Tuesday up to 50 puppies were discovered in the trunk of two cars, when police conducted a search of the vehicle in the Collock area of North Dublin.
Spokesperson Gillian Bird told TheJournal.ie that the van was stopped as it was boarding a UK-bound ferry.
“The pups are in better condition than the animals rescued earlier this week,” she said. “But there are still a number of underlying problems and some of them are still quite young. We estimate the youngest is about six weeks old.”
Once the police investigation is concluded, the DSPA said they will be looking for new homes for the puppies. Potential owners looking to adopt one of the pups can register their details with the DSPCA here.
Puppy Fund Appeal October 2012: