Poor fishie. If he is suffering from poisioning, I would think ammonia poisining would be the most likely suspect - every single betta i got from petco had an ammonia reading of over 4.0
I am wondering if they took water from one of the larger fish tanks and used it for the bettas - that would explain the nitrAte poisioning symptoms...
I got one from walmart that was in about the same condition. what I did was I slowly took out his tank water and replaced it with clean water using a syringe. He could not swim at all the 1st few nights. I kept him in the cup and floated him in a heated tank and used amquel plus as I heard it may help with ammonia poisioning. I also used IAL. After 4 or so days he started eating and would try and flair with is "tank mate". At this point I moved him into his own tank with about 2 inches of water with epsom salt. It took about 5 weeks but he can swim normally now. I dont really know what happened to cause him to swim with a straight back. I left alaska it was crooked and when we got to New York - 10 days later, he could swim fine
The night I took him home
About a week ago