FISH ARTICLES: AEROMONAS (hole in the side disease)

This disease is a severe gram-negative bacterial infection that starts out as small red spots, and soon develops into large ulceration's that eat their way through the fish. As the severity increases and the fish's immune system is being destroyed, multiple symptoms will start to appear. One of the diseases that is caused by Aeromonas bacteria is: Bacterial Hemorrhagic Septicemia (red streaking in fins and body, swelling, bloat, loss of scales, skin eaten away, abscessed ulceration's etc.)

There are several different forms of Aeromonas bacteria. Including viral strains of Aeromonas that cannot be cured with the medications we have today.

We like to use a combination of Oxytetracycline mixed into the feed, and Forma-Green in the water to prevent a secondary fungal infection from developing on the ulceration's. Many people cure the Aeromonas infection with the Oxytetracycline and then find after the completion of the treatment, the sores are still open and red. This is due to saprolegnia fungus that has invaded the ulceration's and is acting like a parasite, eating away at the sores. This is why it is important to use an anti-fungal medication in the water along with the Oxytetracycline in the feed. We like the Forma-Green the best, but you can use a 0.75% Malachite Green solution instead.

If you can separate the infected fish early on and treat them in isolation tanks, you can prevent your whole pond from being infected in most cases. I like to bump up the temperature in the isolation tanks to 75-80° when possible. This will speed up the treatment. We have cured some severe cases of Aeromonas in two weeks with this method.

TREATMENT

OXYTETRACYCLINE

DOSAGE: 2 teaspoons (7.5 Grams) of Oxytetracycline Powder for every 1 pound of koi pellets. Mix the medication with approximately 2 ounces of water. Add this to a spray bottle, and spray the entire contents over the feed. Let air dry. Note: It is important that you do not use any heat element to dry the feed because it will destroy the medication. Use a fan to expedite the drying process if necessary. Feed the medicated feed to the fish once a day for two weeks. Do not feed any other food except for the medicated food during treatment time. You do not need oil or gelatin to get the medication to stick to the food. This is a waste of time, and it pollutes the water.

FORMA-GREEN

We use this solution at 2 drops per gallon, which works out to be 100ML per 1,000 gallons (milliliter measurements can be found on a standard kitchen measuring cup). Dosing this product may vary depending on your water composition. In some areas the water will stay green colored for a week, and in other area's the green is gone in 24 hours. It is important to keep the water green colored, during the entire duration that you are using the antibiotic (which will be around 2 weeks). Plan on using the Forma-Green once every three days. This will prevent a secondary infection from developing in the sores.

Also, remember to sterilize all of your pond equipment with bleach to prevent spreading the disease to any other tanks or ponds. It is also important to obtain a gram scale (diet scale) which can be found at most local retail stores for about $7.00. These medications need to be accurately measured out for effectiveness and to prevent over treating the pond.

Sometimes cases of Aeromonas are so severe that no treatment can reverse the damage done by the bacteria. In these cases I suggest that you remove the infected specimens and give them a humane solution to their suffering by putting them in a bag of water, and then put them in the freezer. We have had customers call us and say that they see bones sticking out of the fish. This is an example of a fish that cannot be saved.

Important differences in Bacterial infections with Koi & Goldfish

Ok, so you saw that picture above with the large ulcer on the Koi. There is another bacteria that will do just as much, or more damage to your fish that is called Pseudomonas bacteria. The way to tell the difference is, that with the pseudomonas bacteria: You will also have fin and tail damage. To treat for pseudomonas, instead of using the treatment listed above... use Neomycin or Kanamycin in the feed instead. Also use the Forma-Green in the water.

A couple of pictures of pseudomonas bacteria. This bacteria is often identified as an aeromonas bacteria and treatments are unsuccessful