Bloated Betta! Is this dropsy?

[morganville]

Housing
What size is your tank? 2.5 gallons
What temperature is your tank? 71 to 75 degrees
Does your tank have a filter? yes
Does your tank have an air stone or other type of aeration? no
Is your tank heated? yes
What tank mates does your betta fish live with? none

Food
What type of food do you feed your betta fish? pellets
How often do you feed your betta fish? once a day, 2 pellets

Maintenance
How often do you perform a water change? weekly
What percentage of the water do you change when you perform a water change? 25%
What type of additives do you add to the water when you perform a water change? tap water conditioner

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? bloated stomach suddenly
How has your betta fish's behavior changed? not much still active
When did you start noticing the symptoms? he was fine this morning and when i came back from classes he was bloated
Have you started treating your fish? If so, how? rushed out and bought some medicine, tetra fungus guard said it treated dropsy so he is in fresh clean water with a bit of that treatment right now just in case i also have tetracycline and erythromycin on hand just in case
Does your fish have any history of being ill? no
How old is your fish (approximately)? ive had him for a few months

[LittleFish2012]

Are the betta's scales raised and "pineconing"? If they are, then this is definitely dropsy.
It's hard to say whether or not this is dropsy. It can be caused by bacteria, a virus, or even parasites.
This may just be something as simple as constipation, but just in case, keep an eye on him. Perhaps fast him for a day. I fast all my fish for a day once a week.
You could also have him in an epsom salt bath- 1-2tsp per gallon (dissolved before adding). This helps with swelling of bodily fluids, should dropsy be the case.

[Pataflafla]

I don't see any bloating. He actually looks a tiny bit skinny. He could be constipated though from the temperature fluctuation. 4 degrees may not seem like a lot, but to a betta it is.

Try to keep it at a steady 78-80 instead since they are tropical fish. In a 2.5, you'll be wanting to do more water changes too. 1 50% and 1 100% is a good weekly schedule for water changes for your tank size.

This doesn't look or sound like a dropsy case, so I wouldn't use any medication. Epsom salt at 1 tsp/gal will be beneficial if he's constipated and won't be harsh on him at all. Always use medications as a last resort.