Serious infections like bacterial gill infections are possible if this was rapid onset. If you have been seeing the gills looking weird or laboring awhile it could be a bad case if gill flukes or if the fish has been exposed to excessive chemicals like formalin or Potassium permanganate it can cause scar tissue that makes it look like the gills are protruding.
Can you post some profile pics so we can see the gills better?
Al