My 4 dogs and several of the cats are chipped. Worth the heartache should they become lost.
If you move, don't forget to call the company where your critter is registered and change your address. You would not believe how many folks do not do this, Fido gets lost, we scan, cannot trace the owner down because they moved and forgot to let the company know.
Although the needle is large, it is hollow allowing for the chip which is the size of a grain of rice. It is inserted between the shoulder blades just under the skin where it stays for the life of the dog for those who wondered.
Not all scanners work on all microchips. Even Universal ones can be persnickety. If your vets scanner does not read it, maybe try the shelter near you.
Did you know you can chip your quilts?