Mystery Bloat Demystified?
New Information on Troubling Condition
The members and staff of UB have been trying tirelessly to devise a treatment or discover a cause, but without input from a veterinarian, we are only hobbyists stabbing blindly at a problem that is frankly above our level of expertise. However, the answer we have been seeking may have been found. Member Dixiesportster generously informed the staff team of a case of this condition detailed on another forum wherein veterinary expertise was gained. The full text can be found in this thread at Aquamaniacs forum. The summary of the findings is as follows:
A necropsy of the fish indicated that the cause of the bloat was fluid retention from organ failure caused by widespread systemic infection with an acid-fast bacteria, thought to be some form of mycobacteria. The bacteria were most abundant in granulomas in the intestines, kidneys, and adipose tissue; the first finding suggests possible oral introduction of the microbe, meaning that it could have come from the betta's food source or from consuming matter in the aquarium.
(Mod note: Mycobacteria are omnipresent in aquatic environments but are generally not pathological in the populations present; I would almost wonder if pernicious populations didn't emerge in waste at the bottom of the tank, which when consumed by the fish caused infection. Purely speculation on my part, of course)
Mycobacteria are very difficult organisms to combat, notorious for diseases such as tuberculosis, and tend to be highly anti-biotic resistant. What's more, the symptoms only become apparent for this specific condition when the fish begins to bloat, which is a sign of kidney failure, meaning that most treatments will be too little, too late. A very early case could possibly be remedied while enough of the kidneys are still functional for recovery if it is caught very early on if aggressively treated with -mycin family anti-biotics, but most OTC fish medications are fairly weak. Until actual treatment attempts occur, it can't be said if any treatment would work, and heavy medication could hasten kidney damage (ironically, the same family of drugs that may be effective is also very toxic to the kidneys).
The symptoms of the disease can be managed by anesthetizing the fish with Finquel, a fish anesthesia compound available legally only through vendors such as Drs. Foster & Smith.com, then using a small insulin syringe to gently draw off excess fluid. This is not a cure - it will simply lessen the fish's discomfort. In many cases, euthanasia may be more kind an option, particularly if you are not comfortable with such a delicate procedure.
This is only one necropsy result from one fish, but the suspicion of the condition being one of mycobacterium origin should be taken very seriously. Fish should be stringently quarantined - information on how can be found here; the article is intended for new fish but is highly applicable to sick fish as well. Also remember that many mycobacterium species can harm humans. This means that you are potentially putting your health at risk working with these animals, so take appropriate safety precautions. Humane destruction of infected animals may be a prudent choice if you have a compromised immune system or live in an environment where young children may have access to the tank and its inhabitant; this is a "better safe than sorry" situation since so little is known.
Hopefully this helps some of you seeking answers. It may not be "the answer," but it IS the most significant finding to date on this terrible condition.
P.S. If anyone with fish who suffered or are suffering from "mystery bloat" would like to share photos for this thread, please PM me! It would be nice to have some pictures for those trying to visually diagnosis.
According to the National Fish Pharmacy, the cause of this condition could be protozoal parasites as those seen in Malwai bloat. The damage to the GI caused by the protozoans could cause native mycobacterium common in aquatic environments to be introduced to wound sites, becoming pathogenic in turn. This could account for the widespread myco infections in the body that would result in kidney failure, the cause of the rapid onset bloating we observe in this condition. Because there has not been an in-depth study of the condition in bettas, this is conjecture - but it is logically sound conjecture by an experienced research organization. The treatment for internal protozoal parasites is food soaked in metronidazol, as well as in the water supply.
Furthermore, a member of another forum had luck treating the symptoms of this condition with GelTek's Ampicillin medicated food. We will post more information on this if it becomes available, but this does suggest that IF myco is causative, it may be possible to manage with anti-biotics if kidney damage is not too severe for survival. This is anectdotal evidence from one fish, but should not be utterly disregarded; it may be valid to attempt duplicating the results, especially if other treatments have failed.