Clam disease

[Tanzy]

We need to confirm what type of bacteria, if any, we are dealing with there. Different kinds of antibiotics are for different type of bacteria. If you are not sure, then the only shot is broad spectrum antibiotics like cipro (which is not available at GP or the average pharmacies).

[TTBoy]

Just curious, isnt Cipro used for anthrax?

[Achilles Tang]

I got this info to share:

This problem is caused by a bacterial infection. Two years ago it was isolated by a lab in Florida to by a bacterial in Vibrio strain (gram-negative). Vibrio bacteria cause a number of human ailments including cholera and acute bacterial diarrhea. More specific pathology for the exact bacteria causing harm to our clams will be available for the San Francisco area outbreak later this week as some dying clams have been sent into a pathology lab specializing in marine organisms. This bacterial problem in ornamental reef clams is not new. It (or something very similar) happened about two years ago too.

As it turns out, Sprung and Delbeck are recommended the tetracycline family of antibiotics for this problem. I just happened to have something on hand, so after I lost 2 of my 3 clams to this problem, I tried an antibiotic from the tetracycline family called minocycline. My last clam, which just yesterday was showing gaping and the classic mucus, seems fine today living in a bath of antibiotics. Treatment was given at 100 mg minocycline per 5 gallons (I read this is close to the common dosage for fish). After 24-48 hours, the water should be replaced in the bucket and treated again at the same dosage for two more days. After that the clam should be returned to a tank separate from the one it caught the disease. In several months, the clam might be able to be returned to the main tank, but the amount of time to wait is anyone's best guess. I AM BASING THIS ROUTINE ON WHAT I'VE READ ONLY! It is NOT proven yet to me personally!

Of the tetracyclines, Delbeck recommends doxycycline in particular probably because of its relatively low affinity to calcium (good in a high-calcium organism). Where does one get that stuff without holding your local doctor hostage? The answer was found about as far from my mind as possible as I set out on the search.

The answer is in racing pigeon care. Racing pigeons are sometimes given a doxycycline solution to prevent respiratory infection after coming home from a race. The concentration of such a solution is, I have read, 500 to 1000 mg/gallon of water. This is 20 to 40 times the strength recommended by fish experts in treating fish bacterial infections. That might be expected too as saltwater organisms are constantly processing water since they have to counter the osmotic pressure that forces them to dehydrate all the time.

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Tetracycline is well known to be effected by calcium, hence the recomendation for double dosage for it and it's derivatives such as maracyn 2 for use in marine aquaria

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The concentration of the doxycycline liquid is 20% doxycycline HCL (by weight) in their formulation. That would mean that 1 teaspoon would treat about 40 gallons. A ml would be 200mg of doxycycline, or enough to treat 8 gallons of clam water. I ended up canceling my own order, though, since I got some doxycycline from a doctor locally.

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Doxycycline is sold as "Bird Biotic" for $11 for 30 or $20 for 100 100mg caps at Lambriar Animal Health Care without a prescription for animals. 100 mg will treat about 4 gallons per day given the routine I used. So, for $20 you get enough to treat about 400 day-gallons from those guys.

I also found a place in Savannah, Georgia called Global Pigeon Supplies that sells a liquid preparation that is enough to treat 800 day-gallons for $22.95 + shipping. One ml of the liquid is 20% doxycycline by weight so I figure 200 mg. That means one ml of that liquid should be added to 8 gallons or so of water for the treatment bath (and, as above, the water has to be swapped out each day and re-treated to stay effective in medicating your clam).

In either case, I doubt the exact dosage is really that important. If you use twice the amount or half, it probably will work either way. But there are some guidelines that I'd follow:

1) Treat the clam in a separate bucket or tank. Antibiotics introduced in the main tank will kill off your biologically filter and crash your tank.

2) I treated my clam for 5 days. I would recommend you treat for AT LEAST 5 days. Even a week or more is not out of the question. Antibiotics do not work well on a "dip" basis. And the clam very well could look perfectly fine after a day or two. DON'T STOP THE TREATMENT PREMATURELY! If you stop the treatment fast, you greatly reduce your chances of the clam being cleared of the infection sufficiently to survive.

2) Treat the clam in darkness or very low light, and provide a phytoplankton food source each day. This is because the tetracycline family of antibiotics break down in bright light, and your clam will need some form of food to get well. Use vinyl tubing and an air pump to keep bubbles rising and moving the water around (use a powerhead if the tank is large enough but not in a few gallons as the temperature can go too high). Use a small heater to keep the water at normal tank temperatures.

3) Don't introduce lots of calcium structures into the treatment tank. I would not, for example, coat the entire bottom with an inch of crushed coral. Keep the crushed coral in a small bowl if you need it to place the clam. This is because doxycycline binds weakly to calcium, and I can imagine that lots of calcium carbonate might bring up the calcium ion concentration in the water very slightly.

4) Change the water and the medication out each day. I would recommend you get the water from the main tank rather than make it fresh. Freshly-made saltwater tends to stress stuff out, and you don't want your clam to be more stressed than it already is.

5) When the clam is put back into the tank, introduce as little as possible water from the treatment tank into the main tank. Again, this antibiotic is poison to the bacteria responsible for your tank's biological filtration.

I hope this helps folks!

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I just lost a crocea to an unknown cause, but it hasn't affected my other clams, knock on wood. In any case, ReefDream, it's funny how you stumbled onto the Doxycycline. I was just reading an article in May's FAMA in Julian Sprung's Reef Notes. He recommended using the same antibiotics to cure ailing elegance corals. He also suggested that it was applicable to a lot of different invertebrates. Good job at finding a cure... hopefully

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[Tanzy]

Just curious, isnt Cipro used for anthrax?

You could. Cipro is wide spectrum, kills almost everything.

AT,

Good luck with the treatment and when are you going to start? Ya, forget to mention that tetracycline binds to calcium thats why they stain teeth yellow, so the clam shell might get stained yellow too.

[Achilles Tang]

I rather have yellow clam shells than dead clams... I hate looking at my collection of bleached white clam shells.