What’s in API’s Finrot and Body Cure

What’s in API’s Fin (Finrot) and Body Cure?

Answer: 250mg Doxycycline per packet.

Application to the water provides variable degrees of absorption. Dirty water, high organics, less absorption. Clean water and no gravel, like in a 5 gallon bath at 78 DF? better absorption.

So it’s a hit or miss. If the water is harder (more calcium), it will work “not as well” and if the water is softer (less calcium mineral content), it will work better.  The pH (alkalinity) of the water is irrelevant. Besides aiding fish immune systems when warmer, temperature of the water is also irrelevant.

You can test for literally EVERYTHING that might be impacting the fish, or thre treatment with the following kit, specifically:

columnaris bacteria
Checks nitrogen (all three ways) and pH and Hardness. Amazing.

The above test kit has the Ammonia reagent on the same pad – unlike Tetra’s *other* offering which has 6 tests on one strip and the Ammonia kit separately. Which is fine, whatevs, it’s just less convenient.

Finrot: Fin and Body Cure by API Ingredients

Finrot should respond well to a sufficient dose of Doxycycline (API Fin and Body Cure) in the water.

Doxycycline has a hard time killing much of anything except Columnaris bacteria / Flavobacterium –  the common cause of “FinRot” and “Tail Rot” with “Cotton Wool” disease which looks like tufts of white or off-white ‘fur’ sticking out of damaged tissues.

This is why they say it won’t hurt your biofilter. It’s just not geared to kill those types of germs. At least not meaningfully.

Fungus can look exactly the same way as Flexo/Flavo/Columnaris bacterial infections, but I have to admit, fungus is “bigger” and “puffier” than cotton-wool bacterial infections. Fungus is almost like a boofy, white ‘Fro’.

This isn’t a stupid product. I mean, it won’t work if you’re neglecting water quality. NOTHING CAN SAVE FISH IN POOR OR COLD WATER.

So you really need to make sure your water is clean, aerated, properly filtered, low in nitrogen byproducts, and neutral or otherwise appropriate in pH.

Then if you’re looking at cotton-wool ‘tufts’ of infection on tail, fins, mouth or body, TRY IT.

Does Doxycycline even WORK in water bath? Could we expect it to work on Finrot, Mouthrot, Tailrot?

Yep. (Reference)

Finrot Article

Dr Erik Johnson is a Marietta, Georgia Veterinarian with a practice in small animal medicine. He graduated from University of Georgia with his Doctorate in 1991. Dr Johnson is the author of several texts on Koi and Pond Fish Health and Disease as well as numerous articles on dog and cat health topics.