Bloated Betta

My female Betta is pretty bloated on the under side of her stomach, she has lost an appetite and will not eat dried bloodworms or Hikari pellets that she usually loves. She also is slightly less active and stays more near the top making a bubble nest. Is this swim bladder or does she just have eggs, I’m planning on doing a water change and then feeding her frozen bloodworms a day or two down the line.

The fish is not having eggs. Although it’s difficult to tell why she's bloated, she’s in a very bad shape. Sorry to be a bearer of bad news, but she’s unlikely to survive. If the fish doesn’t eat it may be better not to feed as uneaten food would only pollute the water.

She's very swollen and chunky, so she was likely getting too much food. Dried bloodworms are also not a good staple food for bettas because they have little nutritional value and expand in the stomach which can cause bloat/constipation issues.

What size tank is she in? How often do you change the water and how much?

Water changes should be done weekly in the most appropriately sized tanks, which for a betta is 5 gallons+ (preferably 10). Smaller tanks need more water changes each week because toxic compounds accumulate more quickly in the smaller volume of water. The only way to remove them is through water changes. If you have some accumulated in the tank that could make her lethargic and contribute to digestive issues.

To help her you could try to do some frequent water changes, every 2 days or so. Vacuum the gravel really well too, and if you can find some frozen or live daphnia, I would suggest trying to feed that. Daphnia has a laxative effect on betta's and is easy for them to digest.

If you can I would recommend testing the water in the tank to see what your water parameters are. With that information, you can change your water change schedule as needed to keep parameters in check.