
Briefly:
Assuming they are a country covered by the PETS travel scheme the earliest you Will be able to bring pup in would be at 10 months of age.
Pup will first have to be Microchipped, then Vaccinated for Rabies, then blood tested (depending on vaccine used between 21 and 30 days after).
If the blood titre comes back at a high enough level then the dog is eligible to enter the UK 6 months after the blood sample was taken that gave a satisfactory titre.
An EU Pet Passport needs to be completed.
The dog when being imported will have to be wormed for Tape Worm using a product containing Praziquantel, and treated for ticks using a Licensed product for this.
This has to be done more than 24 hours but less than 48 hours before checking in for travel to UK on the Ferry route, channel tunnel or the Approved Airline/route.