All NGA registered greyhound are tattooed at around 3 months of age, then registered with the NGA.

So all my crew have tat's. One tat in each ear. The right ear has the month, year and letter. Augie who is 5 his right ear reads 79A= July 1999 and was letter A pup out of his litter.
The left ear has the litter number. So every pup in his litter will have the same left ear number.

I've heard that the chips can sometimes get lost or misplaced in the dogs system. Has anyone ever had this trouble?

If my crew wasn't tattooed I would chip them

Better safe than sorry