seahorse not using her tail

Dear Mel:

If your female is holding her tail stiffly rather than curling it as usual, and is unable to use it to grasp hitching posts, that is often the first indication of a tail infection. A progressive loss of prehensility and increasing tenderness of the tail are the early stages of a bacterial infection usually known as tail rot or white tail disease. It often affects the most distal portions of the tail first, where the oxygen tension is lowest and the circulation is the poorest, which seems to make the tail tip particularly susceptible to such infections.

Has your seahorse tank experienced a temperature spike or been running warmer than usual lately, Mel? That’s been a common problem for seahorse keepers recently due to the summertime heat waves that most of the country has been experiencing, and heat stress is often associated with this condition (i.e., tail rot).

Here is an excerpt on tail rot from my new book (Complete Guide to the Greater Seahorses in the Aquarium, TFH Publications, unpublished). It will describe the affliction in greater detail and explain how it can be treated:

White Tail Disease (Tail Rot)

As you might expect, this problem is due to an infection that attacks the tails of seahorses. The tip of the tail typically turns white and, as the infection spreads, the whiteness moves progressively up the tail and ulcers or open sores begin to form where the skin peels away (Giwojna, Oct. 2003).

Hobbyists usually refer to this problem as Tail Rot or White Tail Disease, but the disease is already well advanced by the time whitening or tissue erosion occurs (Giwojna, Oct. 2003). Early detection makes it much easier to get these infections under control. Some of the early indicators of a tail infection to watch for are discussed below.

The disease begins with a loss of prehensility in the very tip of the tail (Giwojna, Oct. 2003). At this stage, the seahorses can grasp large objects just fine, but cannot take hold of slender objects with a small diameter (Leslie Leddo, pers. com.). Next the loss of prehensility spreads further up the tail and the seahorses begin to act as if their tails are very tender and sensitive. They will drape their tails over objects rather than grasping onto them and begin to drag their tails behind themselves, often arching the end of their tail upward in the shape of "U" (rather than the usual "J" or tight coil) as if to lift it off the ground and keep it from touching anything (Leddo, pers. com.).

This is usually when the tip of the tail becomes white and the loss of coloration starts advancing further and further up the tail (Giwojna, Oct. 2003). At this point, the discolored skin begins to flake or lift up and open wounds and ulcers develop on the most distal portions of the tail (Giwojna, Oct. 2003). The infection attacks the underlying tissues, and the tail is gradually eaten away, often all the way to the bone, exposing the vertebrae (hence the name Tail Rot). Survivors may end up missing the last few segments of their tail (Giwojna, Oct. 2003).

White tail disease is highly contagious disease. I have seen it often in temperate seahorse species suffering from heat stress, as well as in crowded nursery tanks where it spreads through the fry like wildfire (Giwojna, Oct. 2003).

Infected seahorses should be treated with antibiotics in isolation at the first sign of a loss of prehensility in the tip of their tails (otherwise the antibiotics may harm the biofilter in your main tank, creating more problems). There are a few treatment options to consider. Feeding the seahorses with live shrimp that have been gut-loaded or bio-encapsulated with tetracycline/oxytetracycline or minocycline sometimes produces good results (Giwojna, Oct. 2003).

But the treatment I recommend is gradually dropping the temperature of the aquarium, hitting the infection hard with broad-spectrum antibiotics in a hospital tail, and administering Beta Glucan orally to stimulate the seahorse’s immune system and help the affected seahorse fight off the infection.

Neosulfex and Neo3 — both broad-spectrum antibiotics consisting of neomycin combined with sulfa compounds to produce a potent synergistic combination of antibacterials — are the antibiotics available to hobbyists that seem to work best for tail rot. Unfortunately, both of these combo antibiotics have recently become unavailable.

In their absence, most hobbyists have been getting similar results by creating their own version of these medications by combining neomycin sulfate with various sulfa compounds. One that seems to work well is combining neomycin sulfate with triple sulfa. You may be able to get neomycin sulfate and triple sulfa compound at a well-stock LFS. If not, you can obtain both neomycin sulfate powder and triple sulfa powder from National Aquarium Pharmaceuticals. You can order them online at the following site: http://www.fishyfarmacy.com/products.html

Kanamycin sulfate used alone or in conjunction with neomycin sulfate would also be an excellent choice for treating tail rot. Both of these antibiotics are often available at pet shops and fish stores, and they can both be obtained from National Aquarium Pharmaceuticals as well.

As I mentioned above, tetracycline and oxytetracycline can be effective treatments for tail rot when they are administered orally. However, they are useless as bath treatments for marine fishes. This is because calcium and magnesium bind to tetracycline and oxytetracycline, rendering them inactive (Roy Yanong, US Department of Agriculture). Adding tetracycline or oxytetracycline to saltwater in a hospital tank is therefore completely ineffective (Yanong, USDA).

Reducing the water temperature in the hospital tank will further increase the effectiveness of the antibiotics and help your seahorse recover faster. Heat stress is often associated with tail rot and is especially debilitating and dangerous for seahorses due to a number of reasons (Olin Feuerbacher, pers. com.). For one thing, elevated temperatures can have a very detrimental effect on the immune system of fishes. This is because many of the enzymes and proteins involved in their immune response are extremely temperature sensitive (Olin Feuerbacher, pers. com.). Some of these protective enzymes can be denatured and inactivated by an increase of just a few degrees in water temperature (Olin Feuerbacher, pers. com.). So when seahorses are kept at temperatures above their comfort zone, their immune system is compromised and they are unable to fend off diseases they would normally shrug off.

At the same time heat stress is weakening the seahorse’s immune response, the elevated temperatures are increasing the growth rate of microbes and making disease organisms all the more deadly. Research indicates that temperature plays a major role in the regulation of virulence genes (Olin Feuerbacher, pers. com.). As the temperature increases, virulence genes are switched on, so microorganisms that are completely harmless at cooler temperatures suddenly become pathogenic once the water warms up past a certain point. Thus both the population and virulence of the pathogens are dramatically increased at higher temperatures (Olin Feuerbacher, pers. com.).

This is true of Columnaris and certain types of Vibrio. At cool temperatures these bacteria are relatively harmless, but at elevated temperatures they become highly contagious, virulent pathogens that kill quickly. Neil Garrick-Maidment, director of the Seahorse Trust in the UK, reports that he stopped a deadly outbreak of Vibrio among his Hippocampus capensis dead in its tracks and cured the seahorses simply by cooling their aquarium down to 18°C (64.4°F) for a period of weeks. The bacteria simply no longer presented a problem at that temperature.

In short, it makes a lot of sense to reduce the aquarium temps while trying to get an infection such as this under control. Cooling down the microbes and slowing their metabolism and rate of reproduction accordingly can slow any bacterial infection (Giwojna, Oct. 2003).

Tropical seahorses will be fine as low as 68°F (20°C) providing you drop the water temperature gradually. But the temperature does not need to be reduced markedly to have a very beneficial effect on a bacterial infection; just dropping the water temperature a few degrees will be very helpful.

Finally, adding beta glucan to your treatment regimen to boost the healing seahorse’s immune system can also help them fight off this infection. The best way to administer the beta glucan is simply to enrich frozen Mysis with Vibrance and feed it to your seahorse as usual. The Vibrance formulations now include Beta Glucan, a potent immunostimulant, as a primary ingredient. As a result, we can now boost our seahorse’s immune systems and help them fight disease as part of their daily feeding regimen. Enriching our galloping gourmets’ frozen Mysis with Vibrance will give them a daily dose of Beta Glucan to stimulate phagocytosis of certain white cells (macrophages). If the research on Beta Glucan is accurate, this could be a great way to help prevent infections from bacteria, fungus, and viral elements rather than attempting to treat disease outbreaks after the fact.

Not only should Vibrance + Beta Glucan help keep healthy seahorses healthy, it should also help ailing seahorses recover faster. Research indicates that it helps prevent infections and helps wounds heal morfe quickly (Bartelme, 2001). It is safe to use in conjunction with other treatments and has been proven to increase the effectiveness of antibiotics (Bartelme, 2001). It will be great for new arrivals recovering from the rigors of shipping because Beta Glucan is known to alleviate the effects of stress and to help fish recover from exposure to toxins in the water (Bartelme, 2001) . Good stuff!

For more information on the potential benefits of Beta Glucan for aquarium fish, please see the following article:

Click here: Advanced Aquarist Feature Article
http://www.advancedaquarist.com/issues/sept2003/feature.htm

Adminstering Beta Glucan orally via Vibrance-enriched frozen Mysis, which are so naturally rich in highly unsaturated fatty acids (HUFA), is the perfect way to boost the immune response of our seahorses since vitamins and HUFA enhance the capacity of immune system cells that are stimulated by the use of beta glucan (Bartelme, 2001).

You did well to detect this problem while it is still in the early stages, Mel. It’s good that you are so observant and noticed that your female was not using her tail normally right away. If the tail rot is detected early, it should respond well to a treatment regimen consisting of antibiotic therapy, reduced temperature, and beta glucan administered orally. Topical treatments consisting of dipping the tail of the seahorse in disinfectants such as Betadine can also be a useful addition to the other therapies for tail rot we have been discussing.

Best of luck resulting your seahorse’s tail problem, Mel!

Respectfully,
Pete Giwojna

Post edited by: Pete Giwojna, at: 2006/08/22 17:00