Injuries and Parasites
To keep your goldfish happy, you need to protect your fish from parasites.
When it comes to an injury, the most common would include eye inflammation and scale loss. Fish that have telescopic eyes are more prone to eye injuries, sometimes resulting in the whole eye being inflamed. You will need to treat this by swabbing the area with a boric-acid solution, mixed at the same strength as used for humans. Cuts or abrasions should be swabbed with kerosene. A salt Water treatment is also good for promoting healing, as well as scale re-growth.
These are a list of parasites that can harm your fish:
• Anchor worm
• Flukes
• Ichthyophthirius
• Itch
• Leeches
• White Fungus
• Lice
Insects and Other Enemies:
Besides the above list, you need to be aware of other insects or enemies that can harm your fish. Dragon fly larvae and hydra can be a annoying to your fish, but normally a dealt with simply. Beetles and giant Water bugs are the worst insects for your fish. These bugs are rather large, and can bite your fish, handle them carefully, as they can bite humans as well.
The water Scavenger Beetle and the Predacious Diving Beetle are the worst enemies of your goldfish. The beetles, and their larvae, can hurt your fish. Luckily they are easy to spot and kill, even in large ponds. Destroy the larvae as soon as possible, and figure out what it is later!
Be aware of threats from frogs, rats, and birds as well. Cats can be another threat, as well as your own children. If a fish has disappeared, one of these is the best bet over an insect!