Hello!

[billybass]

Hi! I've been keeping fish since I was seven, and now, I'm 17, so I've learned a lot through experiences. I used to keep a betta fish, but after he died, I got guppies. Currently, I have a 10 gallon tank with 5 guppies (2 females, 3 males), and they have been through a lot. One of the fish got dropsy, but after quarantine and medical treatment, she's all good now! She had babies, but many of them died; however, two of them make up the 5 guppies in the tank. Currently, two of my guppies are having issues, and one female has a flat belly and very arched spine, while one of the males swims diagonally with a drooping back. They're both eating though. Any advice really helps.

 

[lewis.r]

Happened to my guppies, and a couple of other fish I have had. To be honest it sounds quite common but I'm 90% this is fish TB (search it on google) I have had experience with these symptoms on a few of my fish and they never seem to get better.
And after searching on google there doesn't seem to be any cure available either.
Best my is to cull or let nature take its course I'm afraid.
But google fish TB and see if it sounds like what your fish have... to me it does