Oscars/ Mouth Rot

Question
I have an Oscar that i believe has mouth rot and I was wondering can Oscars even get mouth rot? If so what are some of the signs I should look for? Is it curable? If so how do i help my buddy get back to his best possible mating self? And can you give me a little background on this disease (where its from?, how do the fish get it? and how did my Osacar set it?)?

Answer
Hi Nicholas,
Mouth rot is called Columnaris Disease.  This disease is often caused by poor water conditions, tanks too small for the fish, lack of oxygen, and poor diet.
Check your water chemistry, and make sure you have no ammonia, no nitrites, and nitrates should be low.  Check your PH also.  Your Ph should be anywhere between 6.8 and 7.0  If your PH is too high, add driftwood to your tank to bring the PH down.  If it is too low, add a few sea shells or crush coral.  Bring it up or down slowly.  Never use chemicals.  The driftwood will bring it down slowly.  If it is too low, make a small bag, add crushed coral to it, and put it into your filter letting the water run over it.  Wait 24 hours, check your water, if it is still too low, add more crushed coral.  One handful at a time.  To make a bag, use white nylon stockings, and rinse the coral well.  You can have your water checked at the pet store, or you can buy these small test kits.  They are always useful to have, since ammonia, and nitrites are the number one reason why fish get sick, and sometimes die.  If you do have ammonia, or nitrites, do a 30% water change, siphoning from the bottom, and 10% everyday until your water chemistry is right.  You cannot cure fish in poor water quality.  Once your water is perfect, cure him with "Triple Sulfa."  This medication should help.  Follow the directions on the package, and be careful not to overdose.
Feed him good food.  Oscars need a good diet to stay healthy.  Clean water, and good diet go a long way in preventing disease.  Do 25% water changes every week, always siphoning from the bottom, and using a good water conditioner such as "Stress Coat" or "AquaPlus.
Food Oscars should have:
A good quality flake, pellet, and sticks
Frozen Bloodworms
Frozen Brine Shrimp
Crustaces that come from rivers
Crickets bought at the pet store
Worms that you have cleaned, and bought at the bait store.  To clean the worms, put them in oats for about one week.
Minnow, the regular kind, bought at the bait store
Frozen fish that come from lakes, and rivers.  Never give him fish from salt water, only fish that come from rivers, and lakes.  The fish must be frozen first, then you unfreeze a piece, and feed it to your Oscar.  He will love it.
Veggies such as peas, broccoli, carrots, and green beans.  I buy mine frozen, and blanch them first, let them cool, and feed these to my Oscar.  Veggies help them with their digestive system, and avoids Swim Bladder Disease, which always begins with constipation.  The day I feed them peas, I feed them nothing else for the rest of the day.  They should have peas once a week.
Fruit, such as mangoes, and bananas now and then.  Never feed him citrus fruit.
Never feed him feeder fish.  They are almost always full of disease, and have no nutritional value.
I hope this helps, and that your Oscar will pull through.
Lynda