[MyBettaJack]

I had to euthanize one of my orange tetra's this afternoon due to what I believe is Columnaris. :blueworry: First off, I want to say that he was suffering greatly. After you see the pictures I hope you'll understand why I opted to put him out of his misery. It wasn't an easy thing to do. On 4-17 I noticed he had a clear, fuzzy "beard." It was very slight and I had to look at him with a flashlight to really see it. I immediately placed him in a hospital tank. Suspecting Columnaris I began treating both the main and QT tank on 4-18 with Furan-2. After I gave the first dose I left to visit relatives out of state and entrusted my father to treat the tanks in my absence. I returned today to find the orange tetra had gotten MUCH worse! The clear fuzz had turned whitish and spread to his gills and mouth. Not good. I know all the symptoms say Columnaris BUT I'm starting to second guess myself and wonder if it's something fungal instead. I've never dealt with Columnaris so I haven't seen it up close and personal. I really want to make sure I do everything I can to give the rest of the fish a fighting chance. SO FAR NO OTHER FISH APPEAR INFECTED. I could really use a second opinion. Here are the pic's and more detailed info. Sorry the picture quality is bad. I put him in a clear plastic bowl to take them. It broke my heart to see him struggling. Poor guy....

1. Size of tank? 13 gallons

2. Water parameters
a. Ammonia? less than .25
b. Nitrite? 0
c. Nitrate? 0
d. pH, KH and GH?
e. Test kit? API Master Test Kit

3. Temperature? currently 75
4. FW (fresh water) or BW (brackish)? FW

5. How long the aquarium has been set up? 4+ months

6. What fish do you have?
~ 3 Neon Tetra's
~ 2 neon Tetra's
~ 3 Guppies (temporarily)
~ 1 Cory Catfish

How many are in your tank? Total of 9. Please note that I normally don't have the guppies in that tank. I have been cycling a five gallon for those three.
How big are they? less than 1 inch with the exception of the catfish who is 1 1/2 in.
How long have you had them? Guppies for 7 months and tetra's 4 months


7. Were the fish placed under quarantine period (minus the first batch from the point wherein the tank is ready to accommodate the inhabitants)? They have always been in the same tank minus the guppies.

8. a. Any live plants? Fake plants? both
b. Sand, gravel, barebottom gravel
c. Rocks, woods, fancy decors? Any hollow decors? Treasure chest, pirate ship, and driftwood with live plants attached

9. a. Filtration? Yes
b. Heater? Yes

10. a. Lighting schedule? What lights are used? LED's on from 7am - 7pm
b. Any sunlight exposure? How long? Not much, not direct light.

11. a. Water change schedule? Approx 2x week
b. Volume of water changed? 50% and a 25%
c. Well water, tap water, RO water? Tap
d. Water conditioner used? Prime.
e. Frequency of gravel/sand (if any) vacuumed? Every water change

12. Foods? Omega one Flakes/Hikari Shrimp 2x week/sinking pellets for catfish
How often are they fed? 2x day

13. a. Any abnormal signs/symptoms? YES. On 4-17 I Noticed a clear fuzz (beard) around the mouth area of one of my orange tetra's. It was VERY slight and hard to see without a flashlight. He wasn't eating which was why I took such a close look at him to begin with.
b. Appearance of poop? Normal
c. Appearance of gills? breathing is slightly rapid

14. a. Have you treated your fish ahead of diagnosis? On thread posted 4-17 I highly suspected Columnaris and chose to treat the tank with Furan-2 in addition to lowering the temp and AQ to aid breathing. Finished Furan treatment yesterday so performed pretty hefty WC today and re-inserted carbon filter.

 

[LittleBlueFishlets]

Here's how to differentiate Columnaris (a type of gram negative bacterial infection) from Saprolegnia (a fungal/mold infection):
Columnaris - White or light colored, cotton-like fuzz that is growing on healthy tissue.
Saprolegnia - Can start out white or light colored, but then darkens within 1 or 2 days. Grows on tissue that has been previously injured, infected or diseased (such as a wound, abrasion or cut).

The white fluff on him looks like Columnaris to me. Columanaris, as I wrote in my other post, is opportunistic. When a fish becomes stressed, it can take hold and cause an infection. It can be aggressive, so if not caught in time, it can kill a fish quickly. It's possible that his immune system was weaker than that of the other fish in the tank, which made him more susceptible to an infection - and then less able to fight it off.

You've already treated the tank with Furan 2, and it looks like none of the other fish are showing any signs of illness. Furan is very effective at killing the gram-negative type of bacteria that causes Columnaris.

At this point, I would just monitor the tank. Also, I would:
- Do frequent water changes. This will physically remove any bacteria or toxins in the water.
- Minimize stress. (For example, if there's any fin nipping, remove the offender, etc.)
- Feed quality food. This will help support their immune system, which will allow them to fight off any bacteria.

Generally, if the fish remain healthy and free from stress (environmental, physical, etc), then their immune systems are usually capable of fighting off the bacteria that causes Columnaris. Since you've used the Furan 2, it should have killed the bacteria in the tank. And the frequent water changes will also remove bacteria or toxins.