Ireland’s new dog microchipping laws have just come into affect: in essence, you cannot sell puppies now if they are not microchipped and registered.
The new compulsory dog microchipping laws in Ireland
Related articles:
Article
A balanced risk-benefit discussion on microchipping of dogs | The Telegraph
New Dog Microchipping Laws | East Coast Radio
TV3 Video
Please note that I am unable to answer veterinary questions in comments. If you have questions or concerns about your pet's health it is always better to contact your vet.