Rod Bacterium & Secondary Infections


Niles, originally uploaded by SecretAgent99.

Q: LP wrote,

[I] just discovered your site and blog. So well done and informative. Thank you for your interest and time in sharing with others. I understand you probably have tons of ??? sent your way so I understand if you cannot answer here or on your blog. My 5 yr old son has a Betta for a year in an unfiltered 2.5 gallon tank with a live plant, snail and weekly water changes. Happy, lively fish until we noticed tiny fin on top of body was white and a bit fuzzy – more white than fuzzy. This was about 4 weeks ago.

1. I did a 75% water change and found some yukky debris under the plant and stones and realized his water was not as clean as I thought and assume his illness was brought about by the bad water.

2. Started doing water changes every 3rd day and he seemed to be okay but still white stuff.

3. Treated with Tetracycline (fish store guy recommeneded) according to directions for 2.5 gallon tank. White stuff seemed improved.

4. Continued frequent water changes and treated 1 more time the following week.

(Sadly, didn’t know to take out snail and now he looks really bad. I think he’s dying and I don’t kmow how to help him. Live and leaarn.)

5. Went away this weekend and returned to find Betta on his side. Can’t get down to the bottom of tank. (swim bladder now affected???) and has a shadow of white under his skin beneath fiin area as if the problem is spreading under his skin or maybe it’s on surface and it just looks underneath.

He’s eating and swimming but I fear he’s going to die if this keeps spreading. Short of attempting surgery which I’ve read about and am not at all comfortable trying, do you think I should treat the water again according to instructions. In other words, how many times should I repeat the med? I changed the water again yesterday.

Any advice is appreciated and if Bozyie makes it, we’ll be thrilled. If not, I’ve learned so much from your site and will be back for more ideas on how to set up a little more sophisticated aquarium for my little boy. We don’t have much space for a big tank with lots of filtration gadgets but I’ve seen some nice smallish set ups on your blog.

A: I will help as best I can but it can be difficult to understand exactly what is happening to your fish. It sounds like some sort of infection, possibly bacterial. Your betta may have been infected with some sort of rod bacterium like Flavobacterium columnare or something similar. These are a gram-negative bacterium and would best be treated with an antibiotic like minocycline. The tetracycline may have helped with a secondary infection (possibly gram-positive) but wasn’t effective against the entire problem. It’s also possible that the infection was resistant to the tetracycline. A third possibility is that a second course of the antibiotic was needed to be totally effective. If you feel the tetracycline was effective then you may want to continue a second course. If you’re not sure you could do a combination treatment of gram-negative and gram-positive treating antibiotics like a combination of Mardel’s Maracyn and Maracyn-Two or an equivalent depending on where you live.

Whenever treating sick fish it is best to remove them from the community tank and to treat them in a hospital tank. This keeps other fish (or snails in your case) safe from the effects of harsh medication. It will also ensure your biological filtration (helpful bacteria) aren’t effected if your tank is cycled. I hope your snail was able to recover. Fortunately, antibiotics are less dangerous to snails then many other medications like anti-parasitics. Still, they can be hard on any aquatic animal.

The swim bladder problem may be a subsequent symptom of an internal secondary infection. If you can get your antibiotics in food form (some fish stores carry it) then you will have a head start treating any internal infections. Antibiotics that you add to the water often work well with external infections but aren’t always as effective inside the fish.

Keep up with your water changes but more importantly, be sure to follow the directions closely on the medication package. Once he recovers, those water changes will be important for maintaining good health.

I hope your little guy bounces back and is exploring and blowing bubble nests again soon.

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Christie F is a Betta splendens hobbyist that enjoys spending time caring for her fish and helping new betta keepers learn the ropes. More posts by:

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