Disease or just elderly??

[Rampage]

Hello,
I purchased my betta about 3 years ago. Up until approx 2 weeks ago he has been extremely active, eating, healthy... I first noticed him staying at the top of his tank in a vertical position, he then lost appetite, I've noticed in the last week his left eye has become grey and swollen, and now he prefers the bottom of the tank resting on his side only to surface for air and sometimes does a lap and rests om the bottom else where. I'm taking the water in tomorrow for testing but I've never had a problem with the water previously? Is there a chance to save him? Or should I find a way to euthanize? He has t eaten for two weeks and I'm concerned he's suffering. Any help would be appreciated :)

[ShyDog]

Sorry to hear about your fish :(

would you mind filling this out? It'll help the experts when they come around.

Housing
What size is your tank?
What temperature is your tank?
Does your tank have a filter?
Does your tank have an air stone or other type of aeration?
Is your tank heated?
What tank mates does your betta fish live with?

Food
What type of food do you feed your betta fish?
How often do you feed your betta fish?

Maintenance
How often do you perform a water change?
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change?

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?
How has your betta fish's behavior changed?
When did you start noticing the symptoms?
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?

[Myates]

Aww poor guy, welcome to the forum, sorry it's under this condition though.

Yes, filling out the above will help greatly. But right now I would place him in a smaller container/tank. If he is in a 1 gal, you can keep him in that.

For now, with the swollen eye and vertical position I would suggest using Epsom Salt which you can purchase anywhere there is a pharmacy at, such as Walmart.

I'd start out with 1 tsp of Epsom Salt per gallon (dissolve it prior to adding him in it, also dose for full volume of the tank with water conditioner), daily 100% water changes with like-temp water until you notice an improvement in him, I'd say about 10 days.
3-5 years is their average life span, so he is up there, but could still go on for a couple years possibly.

Also his lethargy and not eating may be temp related, which once you fill out the questions above, we can get an idea on if there is anything else happening with him.

[Rampage]

Size of tank? 2.5 us gallon tank/8.57 liters
Temp? 26? In the middle of the green zone?
That's it for housing...
Food? Was once a day 5 pellets maybe 2 blood worms... Haven't seen him eat for approx 2 weeks but there are bits of food I have put it that he maybe eating but haven't caught him in action?
Water change probably every two weeks, 75% new water probably, I just use the tap water and add a liquid neutralizer from pet store.
Waiting for results of water testing as we speak...