Revenue officers at Dublin Port have seized three puppies and an adult dog that were being shipped to the UK.
The animals were taken into custody because the person accompanying the dogs did not have pet passports for the animals and nor were they microchipped.
The German Shepherd puppies were transferred into the care of the DSPCA where they are receiving veterinary attention.
It follows the rescue and return to Ireland of 27 puppies after they were found in a van in Scotland.
The Irish Society of the Prevention of Cruelty to Animals (ISPCC) said the puppies were intercepted on arrival at Cairnryan ferry port.
“The dogs and puppies which include Chihuahua x, Spaniel x and Collie type puppies of various ages are believed to have originated from the Republic of Ireland,” the group said in a statement.