Goldfish Disease

Question
Hi,
I recently purchased a black moor goldfish from petco and I'm not sure if something is wrong with it. His dorsal fin is down. I have had goldfish before that have put down their dorsal fin and then 2 days later, died. If this is a disease please let my know the name of it and the treatment.
Thank you.

Answer
Hi Sarah:  Usually goldfish and other fish will show signs of clamped fins is when the water quality is poor. Monitoring water quality in goldfish is very important because they tend to be rather messy fish.  pH is another issue that you must check because it will also cause clamped fins especially if the pH has dropped significantly. Internal Parasites can also be a cause of clamped fins. I would first start with a water test to check your water chemistry.  Most aquarium stores will do this for you for free.  If your water chemistry levels are ok then I would look for signs of aggression from other fish.  The last possibility would be a disease called Flukes and that can be treated with medication.

So Check your water chemistry and let me know the values of the ammonia, pH, and nitrites.  Do a 30% water change regardless and make sure you are cleaning the gravel.  Goldfish poop a lot and the poop will lay in the gravel and cause all kinds of issues.  Keep me posted... dave