sick kissing gourami

Question
Hi Chris,
I have two pink kissing gouramis in a large tank with a small tiger barb, a huge plecosthemus and one tiny neon. They have lived together for several years and have always been healthy. I recently did a major cleaning on the tank, which is the only change in their habitat that has been made in over a year (no new tank decorations or anything like that). The larger of the two pink gouramis is now looking unhealthy. His tail and some of his other fins look a little ragged, and he seems to be lethargic. It looks to me like his face might be a little swollen, but I'm not sure. The other gourami is harassing him and "kissing" around the areas on the tail that look a little discolored. I don't see any obvious parasite or fungus, and for the moment he's still swimming and active at least some of the time. I don't think he's eating much. Should I be treating him for some type of illness or do you think he's just old? I have had him for only two years, but before that my friend had the tank and she had him for at least a couple of years...maybe more like 5 or 6. Any help you could provide would be appreciated!

Answer
The kissing action of Kissing Gouramis do is actually aggression, its not affection like most people think, sounds like you have 2 males that have been in a territory standoff for the last year and when you changed the tank around it broke up the Territories, one established his new area first and was able to dominate the other and is now showing his dominance by beating the crap out of the other one, often this will stop after a while but in your case it sounds like the male is going to continue until the other male is gone.  If you have another aquarium you can put the damaged male into I would go that direction, otherwise its likely he will be dead soon.