HELP my zebra looks sick

Question
I have 6 zebra danios, and one of them has always been bigger but about 2 weeks ago it started to look really Fat and Scaly the scales look white and he hardly swims anymore he just stays at the corner of the tank

Answer
Hi German
Well hard to say for sure, but from what you described, it sounds like it may be dropsy.  Dropsy is a condition in fish, basically they're kidneys are shutting down for whatever reason(internal bacterial or parasitic infection, poor water quality, old age, cancer etc.), and they start retaining water.  Towards the end stages the fish's scales will stand out and give it the classic pinecone appearance.  Usually when that happens, they end up dying within a few days.  Dropsy is generally not treatable, probably because it's difficult to tell what's causing the problem.  Sometimes a medicated food can help, but honesly, it probably won't.  It is possible it's a constipation issue, I really don't think so, but maybe.  Anyway, the treatment won't hurt to try, just feed the fish(all of them, won't hurt any of them and it's good for them)a pea split open so they can eat the inside.  Do that for 2 or 3 days and see if it helps any.

Good luck!

Christy