Geriatric Betta Fish

Question
I have had my male betta fish for five years now. He has had a good long
life, and has survived (miraculously) a bout of popeye as well as another
infection that I was not able to identify. For the past two weeks his behaviour
has changed drastically. Where he used to swim around and protect his
bowl, even jumping out of the water to attack anything above his bowl (my
finger included) he now mostly lays on his side on the bottom of his bowl and
then will vigorously swim to the top of his bowl, zoom around with his head
out of the water a few times and then float down to the bottom, where he
lays motionless. Usually after about 5 minutes he will right himself. However,
his swimming is very laboured.
So I am just wondering, is he just at the end of his life and his body is failing
him, or is there something I can do?  I have considered making the depth of
his bowl less- so that he can get to the top to breath easier ( knowing
ofcourse that I will have to change the water much more frequently..)
Any suggestions would be appreciates!

Answer
Hi Amanda,
Can you see if his tummy is swollen.  His tummy is just below his chin.  If it is, he has Swim Bladder Disease which is due to constipation, and sometimes poor diet.  Try feeding him a frozen cooked pea.  Remove the outer layer, and cut it into tiny pieces.  Feed the pieces to your betta one at a time, making sure he eats it.  Do not feed him anything else for two days.  He must waste.  You should put a little silk plant in his bowl for him to rest on.  
If he won't eat, and does not waste, try Kanamycin which is very good for SBD.  If you cannot find Kanamycin, then buy Tetracycline or Furan 2.  Follow the directions on the package, do not overdose, and remove any salt if any in his tank.
Does he have clamped fins?  or are they ragged?  Have you seen a change in colour?  Is his water cold?  Look for any sign of stress. Any information you can give me will help identify what is wrong.
When we are lucky enough to buy our bettas young, they may live up to 7 or 8 years.  Unfortunately we do not know their age when we buy them.
Watch him carefully, and get back to me with more details if you can.
Lynda