[bananafish]

I'm terrified I'm going to lose him!

Housing
What size is your tank? 3 gallon
What temperature is your tank? 78
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? N/A

Food
What type of food do you feed your betta fish? Bio-Gold pellets and occasional blood worms
How often do you feed your betta fish? 3 pellets 2x daily, fast on weekends

Maintenance
How often do you perform a water change? 1x weekly
What percentage of the water do you change when you perform a water change? 75%
What type of additives do you add to the water when you perform a water change? API Stress Coat +

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

Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: about 2.5ppm
pH: 7.0
Hardness: --
Alkalinity: --

Symptoms and Treatment
How has your betta fish's appearance changed? His mouth appears swollen and cauliflower-like
How has your betta fish's behavior changed? He's hiding a bit and listing slightly to one side when relaxing
When did you start noticing the symptoms? This morning
Have you started treating your fish? If so, how? No
Does your fish have any history of being ill? No.
How old is your fish (approximately)? No idea. 8-10 months maybe?

 

[bananafish]

Here's a better pic of poor Wraith's mouth.

 

[Pataflafla]

Not sure what the cause might be, but maybe try treating with aquarium salt at 1 tsp/gal and move up to 2 tsp/gal if no improvement is shown in a few days.

Since it's his mouth that is the problem, if t gets worse it might inhibit his ability to eat. f he's not showing improvement with the higher dose of salt after a few days of it, I'd stop salt and start on an anti-bacterial medication to see if that would help.

Has there been any change in the area at all? Nothing stringy attached to it or cauleyflower-like growth?