
I have had an adult done and the tattooist has runa session at training classes to do adults. some wimp out and squeal, but I had the same when I had one of mine chipped.
My youngest was chipped as a pup and was none to keen on the Vet at next vet visit. The Vet beeing bright and freindly soon won ehr over.
I am sure your dogs will have plenty of necessary but unpleasnat expereinces like jabs having blood taken etc over the years. What I find is important is your reaction.
A bit like when a toddler falls over and wils. My Dad always used to say look at the hole ypou have made or what have you, thus distractin the tot from it's hurt.
We all know that when pups show fear it is never a good iddea to sympathise.
MY TATTOOIST ALWAYS RUBES THE EARS VIGOROUSLY TO SOOTHE
AND TO GET THE INK IN WELL, also has a bright and freindly attitude, and pups quickly forget especilly if given something to play with or a treat. After all they inflict much worse on each other regulary while playing, nipping wears and tails, and the victim squeals goes off and forgets about it.