GShorty, just found this online:
From what I have been able to gather what is commonly referred to as "Duck Lips" is a bacterial infection. The info below was copied from an old post on a FH forum. (I don't recall which one?) It makes more sense to me than anything else I have ever read on the subject. In some cases it can act very swiftly, so I suggest that you treat ASAP and DO NOT RAISE THE TEMP of your tank, flexibacter bacteria thrives at higher temps.
And as Cam stated once it hits a certain stage, your fishes days are probably numbered.
The cause of your fish's "duck-lips" or more commonly called "mouth rot" is because of the pathogen Flexibacter columnaris (Flavobacterium columnare) that is very common with imported FH, Bettas, and Livebearers.
This is a disease that acts quickly in the acute form & slower in the chronic form.
You do NOT want to raise the temp at all!!! nonono
The reason is because Flavobacterium columnare thrives and reproduces faster in warm water especially at 84-86 degrees!
Keep the water between 75-76 degrees.
Treat the fish with Maracyn AND Maracyn 2. This is a safety caution to wipe out this nasty bug. It is completely safe and as a bonus it will kill off any Aeromonas which is very often apart of a Flex infected FH.
Because you treat with antibiotics you must have the medication at the proper level or it will not work at all, thus dose at FULL strength.
With FHs having the tendency to get this bug in virulent forms I advise to have the treatment continued to 15 days for serious infections/10 days for less serious infections even if all looks fine during the early stages of treatment.
Here is a slide show showing treatment of Flex on a small Betta fish:
http/www.flippersandfins.net/Flexshow.htm (http
/www.flippersandfins.net/Flexshow.htm)
Here is an article that goes into further detail about this bacterial horror.
http/www.flippersandfins.net/flexibacter.htm (http
/www.flippersandfins.net/flexibacter.htm)
Here's more info on the same disease, and another plan of action with meds that should be effective.
http/www.americanaquariumproducts.com/Columnaris.html
Treatment - Furan 2 (60 mg Nitrofurazone and 25 mg Furazolidone per packet) & Kanaplex (Kanamycin Sulfate) combination.
HTH