I got my Canon EOS 7D in India in 2011 and have clicked some great snaps with it. And to be fair, it hasn't given me any trouble since purchase. So much so that I never had to take the camera for repair or any major overhaul.
Apart from a slight decline in photo sharpness over the years, there hasn't been anything majorly wrong with it.
Should I take the camera to the service center for an overhaul? Is there a concept of getting your DSLR serviced? If yes, what should I tell the repair guy, considering that there is nothing really wrong with the Camera.