black spots on a 10 year old goldfish

Question
hey my friend's goldfish which she has had for 10 years suddenly got tons of black spots all over his body. He seems to get better than worse. Right now the condition is staying the same and he seems to have temporary paralisis. please Please PLEASE help us figure out what is wrong with simba and how we can help him and the other 3 fish (who dont have it (yet))
Love Joelle

Answer
Hi Joelle,
Black spots are usually caused by poor water conditions.  If you have ammonia or nitrates in your tank, then do a major water change about 50%, wait a day, and check again..if there is still ammonia or nitrates change 25% of the water, then wait a day ..check again.  Do this until your water is free of ammonia, and nitrates.  You can buy ammonia and nitrate test kits at the pet store, and they should be number one in your fish cabinet.  Water changes every week is very important to fish.  Ammonia is the number one killer of fish.
Over crowding, overfeeding, not enough water changes leads to ammonia burn.  This is a killer for fish, so check your water first before you do anything else.
If the black spots are raised upwards, it is a fungal disease.  You must treat your tank with fungus medication that you will find at your pet store, and one tablespoon of aquarium salt to five gallons of water.  Dilute it first.
Other black spot diseases are fond in fish that live in ponds with snails. These black spots are a parasite. I don't think this is your problem since he is in an aquarium, and you have had him for a long time.  Hope he gets better quickly.
Hope this helps
Lynda