Missing scales

As you know I now have two goldfish ( well one fantail and one black one), and all seems to have been ok with them. Today though I noticed that the fantail has lost a couple of scales off its side. Its swimming ok and is active as usual.

Could they have been fighting ( I have never seen then being aggressive), or is there something wrong with it? How should I treat it and what could have caused it??

Sorry for all the questions but I would welcome some advice

This happened with my Black Moor a while ago, carole. It was missing some scales off its body - never figured out whether it was down to fighting or if it just scraped itself off something. Anyway, clean water and adding some Melafix/Pimafix to help prevent infection meant they grew back fine.

My fantail lost a few scales when he decided to jump out of a container on the kitchen worktop, and fell 3ft onto the floor! .

Surprisingly it survived the experience apart from losing the scales, and as Mary has said Melafix seems to work well. Also they do seem to scrape themselves on ornaments, so be careful what you have in the tank.