pond fish

[alegna#45]

one of my koi has a very swollen belly and has now developed a black spot on one side, does anyone know what this could be? Thought it might be pregnant at first but its been like this for over a month now.

[hammerman]

Swollen bellies in fish can indicate several things.

1) Dropsy....this is usually accompanied with the scales sticking out like a pine cone. This is a bacterial infection and is very hard to treat. A vet may be able to help.

2) general bacterial infections can cause this too....a broad spectrum bacteriacide may be able to help.

3) The fish may be a female and be full of eggs. This doesn't mean the fish is "pregnant" to some degree...it's just that she's ready to spawn. If conditions are not right or there are either no males present or un-willing males, the female will usually absorb the spawn back into her body.

If your water conditions are good, the fish is eating well and behaving normal, i'd leave well alone before reacing for the bottle of chemicals.

Your fishes behaviour is always a good indicator of any problems....fish gulping for air, not feeding, swimming constantly in the flow from the filter ot air bubbles or swimming with clamped up fins are always a good sign something is wrong.

As for the black spot....koi can go through many colour changes depending on what variety it is. I have had yellow ogons turn into ki matsuba and platinum ogons turn completely black !!!

Good luck

[alegna#45]

hammerman, many thanks for your very detailed reply, I have taken note of all you said and as the fish seems to be quite happy, eats well, still mixes with the other fish and doesn't seem to be having any problems, I will just keep watching to see if anything progresses further, thanks again.