Howdy!

This isn't a disease. It is one of two things, and probably a combination of the two. Bird damage and thorn damage. Birds peck at the rind. Further, squirrels, rodents, and other animals might do the same, but this damage looks like bird pecking. Further, if you have thorns along the trunk and larger branches, these can scar the fruit when the move around in the wind. One image shows a little leaf miner insect damage in the leaf, but that isn't a cause to worry. So,...

Simply look for thorns and just cut them with a pruner or bend them back to snap off. For the birds...well, try bird netting or maybe get a cat.

Hope this helps. Good day,

Boone