What indicates whether my outdoor goldfish are healthy or ill?

Question

I keep goldfish in large outdoor pots (homemade ponds). Other than noting their swiftness when surfacing for food, it is difficult to determine if my goldfish are unwell. It is only obvious they are sick when they start to float sideways; they usually die soon after. I would like to be able to recognize sickness before they get to such a critical stage.

Is it a sign of good health when goldfish rise quickly and gobble up the food?

Are there other signs to indicate if my fish are healthy (or sick)?

Answer 1

If you are able to spot any damage, growths, or abnormal behavior like swimming on their side or gasping for air, it would be a sign. Lethargy and disinterest in food is probably the easiest way to tell.

Not sure what type of goldfish you are keeping, but unless the pots are huge, and you're providing some type of filtration, they're not very well suited for any type of fish. Your typical comet feeder goldfish are very messy and require about 30 gallons (114 liters) of water each for them to survive long term. Koi would need substantially more volume. Both need some mechanism of filtration.