mouth stuck open

[noop]

this morning one of my male guppies was dead. his mouth was wide open and his face looked a bit mad. and one of my zebra danios seems to have its mouth stuck open, its lower jaw protruding a bit. it also has a few rusty coloured spots down its flanks. can anyone tell me what disease this is?

i've just treated the water with anti-fungus/fin-rot stuff. should i isolate the sick fish?

 

[snowyangel]

when you say "rusty" do u mean sort of red spots? those could be sores/burns caused by bad water conditions(like ammonia). Have you tested your water for ammonia, nitrite or ph?

 

[noop]

levels were ok on sunday. will test again when i get home from work

spots were browny-red