In Canada, any pup that is registered with the CKC must be either micro-chipped or must be tattooed by the breeder before it is sold.
Baxter was tattooed by his breeder, but I did have Baxter chipped at the same time of his neuter. It was the AVID chip.
I agree with Gretchen, most people will not look in the groin of an adult Rottweiler to check for a tattoo.
I have never heard of any dogs having problems with the chips.
Gina