
The leg tattoo can be quite easily altered as they are done the same way human tattooes are, the now long defunct UK tattoo register(nothing to do with the NDTR)used this method & I remember a friends dog having scabs(or similar) afterwards over the tattoo site just as I am told human tattooes heal.
When a dog is tattooed it is the norm(actually a requirement)of the NDTR that the tattooist has an assistant to hold the dog whether it is a puppy or an adult. Because the person holding the dog is
not the owner/breeder & experienced with dogs, the dogs don't struggle & it's only more difficult when the dog is an adult, if the dog has huge ears as an adult(like Basset for example)to get the tattoo into the centre of the ear.
The ear tattoo is designed to prevent anyone even attempting to alter the numbers-the 9 is an odd shape & the 5 has a flat top so they could not be altered to an 8 for example
As the main reason for dog theft is for resale removing an ear would make the dog unsellable-something the thieves that stole 4 Gayville GSD puppies found, they wwere recovered unhurt within hours of the theft
My BC screamed the place down when he was chipped(for his PP) yet he only squeaked when he was tattooed & his tattoo was readable after less than 48 hours(have a look on his page on my website in my profile)one year on his tattoo is still clear & not very intrusive as his ears are not erect, he does of course have a an NDTR tag stating he is ear tattooed as well as his obligatory address tag, chip tag & missing pet bureau tag