Hey look! A quote from that page!
Possible cures
This disease must be caught early to maximise the chance of saving an affected fish, and even then the disease is difficult to cure. Previously, antibiotics prescribed by a vet were the only means of treatment for those countries (including the UK) where antibiotics cannot be purchased over-the-counter. There are now commercially available remedies which may help. These include Interpet #9 Anti Internal Bacteria and Waterlife's Octozin. The addition of salt (1 tsp/gallon) may also be beneficial.
Dropsy is not usually considered to be particularly contagious, so it should not spread to other healthy fish - dead fish should be removed immediately however, to avoid cannibalism. However, bear in mind that there is more than one cause of dropsy, so in some cases the infective agent could be contagious. It is preferable to carry out treatment in a hospital tank where available.
Hmm let's see...
"This disease must be caught early to maximise the chance of saving an affected fish, and even then the disease is difficult to cure."
Said that already..
The addition of salt (1 tsp/gallon) may also be beneficial.
Wow.. right again.. no proof.
in some cases the infective agent could be contagious. It is preferable to carry out treatment in a hospital tank where available.
Holy poop batman! I'm right again!