Re:White swollen spot on horses tail!

Pete Giwojna

Dear Ricky:

Yes, sir, it sounds as if your seahorse has an infected tail and it would be appropriate to treated for tail rot or white tail disease as soon as possible. Unfortunately, both Neosulfex and Wound Control are no longer available, but there are other antibiotics that are just as effective, or even more so, which you can substitute.

Tail rot, a.k.a. white tail disease or ulcerative dermatitis of the tail tip, can result from a number of causes. It can develop when a mechanical injury to the tail, such as a cut or scrape, becomes infected. Certain ciliates and protozoan parasites can attack the skin of seahorses, and when their integument is compromised, secondary bacterial and fungal infections may set in, resulting in tail rot. Likewise, cnidarian stings or the embedded spicules from a bristleworm can become infected and lead to tail rot. Many times an underlying bacterial infection (Vibrio, Pseudomonas or Mycobacterium) may be the primary cause of the tissue erosion and ulceration that’s so characteristic of tail rot. It is often associated with heat stress, particularly in temperate seahorses that have experienced a temperature spike during a summertime heat wave.

The tip of the tail is especially prone to infection because blood-oxygen levels are often deficient in the extremities — oxygen tension is lowest in the most distal part of the tail — and the bacteria that are responsible for tail rot prefer a low oxygen environment. A dirty substrate can be a contributing factor in some cases, and stress is almost always involved. The seahorse’s tail is prone to scrapes and abrasions as well as injuries such as stings from anemones or bristleworms spicules because it is used to grasp objects and often in contact with the substrate.

Disease-causing (pathogenic) bacteria such as the ones that cause tail rot are opportunistic invaders that are normally present in low numbers but don’t cause problems until the fish is injured, stressed, infested with parasites or otherwise weakened (Indiviglio, 2002). They will then take advantage of the overtaxed seahorse’s impaired immune system and reproduce extremely quickly, causing a variety of illnesses and problems (Basleer, 2000). Some of these are specific to seahorses, such as snout rot and white tail disease, and others are common to all fishes (Mycobacteriosis).

One of the best ways to prevent tail rot and other disease problems is to provide them with a stress-free environment. Many of the parasites and pathogens that plague our pampered ponies are ubiquitous — present in low numbers in most everyone’s systems or within the seahorse’s body itself (Indiviglio, 2002). As a rule, healthy fish resist such microorganisms easily, and they only become a problem when seahorse’s immune system has been impaired, leaving it susceptible to disease (Indiviglio, 2002). Chronic low-level stress is one of the primary factors that suppresses the immune system and weakens the immune response, opening the way to infection and disease (Indiviglio, 2002). Long-term exposure to stressful conditions is very debilitating. Among other effects, it results in the build up of lactic acid and lowers the pH of the blood, which can have dire consequences for seahorses for reasons we’ll discuss later.

A progressive loss of prehensility and increasing discoloration beginning at the tip of the tail are the initial stages of tail rot or white tail disease. As I mentioned, 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.

Here is an excerpt on tail rot from my new book (Complete Guide to the Greater Seahorses in the Aquarium, unpublished):

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.

Tetracycline antibiotics administered orally and immersion in the following antibiotics are known to be effective in treating tail rot: 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, Neosulfex is no longer available but you may be able to obtain Neo3 from the following vendor:

If not, 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 Fish Pharmaceuticals. You can order them online at the following site:

Kanamycin sulfate used alone or in conjunction with neomycin sulfate would also be an excellent choice for treating tail rot, both of which can be combined safely with triple sulfa.

Kanamycin sulfate powder

USE: Gram-negative bacteria for resistant strains of piscine tuberculosis and other bacterial infections. Works especially well in salt water aquariums.

DOSAGE 1/4 teaspoon per 20 gallons of water. Treat every 24 hours with a 25% water change before each treatment. Treat for 10 days. For piscine tuberculosis, use for up to 30 days.

This is a potent broad-spectrum, gram+/gram- antibiotic. It is
wonderfully effective for aquarium use because it is one of the few
antibiotics that dissolves well in saltwater and that is readily
absorbed through the skin of the fish. That makes it the treatment of
choice for treating many bacterial infections in seahorses. Kanamycin
can be combined safely with neomycin to further increase its
efficacy. Like other gram-negative antibiotics, it will destroy your
biofiltration and should be used in a hospital tank only.

Neomycin sulfate powder

USE: Gram-negative bacteria (Pseudomonas), piscine tuberculosis and other bacterial infections. Works well in freshwater or saltwater aquariums.

DOSAGE 1/4 teaspoon per 10 gallons of water. Treat every 24 hours with a 25% water change before each treatment. Treat for 10 days. For piscine tuberculosis, use for up to 30 days.

Neomycin is a very potent gram-negative antibiotic. Most of
infections that plague marine fish are gram-negative, so neomycin
sulfate can be a wonder drug for seahorses (Burns, 2002). As
mentioned above, it can even be combined with other medications such
as kanamycin or nifurpirinol for increased efficacy. For example,
kanamycin/neomycin is tremendous for treating bacterial infections,
while nifurpirinol/neomycin makes a combination that packs a heckuva
wallop for treating mixed bacterial/fungal infections or problems of
unknown nature. Keep it on hand at all times.

Neomycin will destroy beneficial bacteria and disrupt your biological
filtration, so be sure to administer the drug in a hospital tank.

You can get both kanamycin sulfate and neomycin sulfate from the following vendor’s:

Click here: Fish Medications

As I mentioned above, tetracycline in 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), but administering the antibiotics orally can produce good results.

But if you can obtain it, Baytril administered as a series of baths may be the most effective medication for tail rot. Baytril is a powerful new broad-spectrum antibiotic that is effective against both gram-negative and gram-positive bacteria and is widely used to treat marine fish. It is a more potent antibiotic than aminoglycosides such as kanamycin or neomycin, but you will probably have to obtain it from your veterinarian. A 7-day treatment regimen for the liquid form of Baytril is recommended as follows:

Day 1: a five hour bath in Baytril at a concentration of 22.7 mg/ml.
Day 2: perform a 50% water change in the treatment tank and administer a 5-hour bath in Baytril at half strength (11.4 mg/ml).
Days 3-7: repeat the procedure for day 2 — a 50% water change followed by a five hour bath in Baytril at a concentration of 11.4 mg/ml.

If you cannot obtain Baytril, then treating the seahorse with Neo3 or else a combination of kanamyacin and/or neomycin used in conjunction with triple sulfa are the antibiotics that will produce the best results.

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:

I am not sure if it is of any help but I recently had a problem with vibriosis
in Hippocampus capensis coupled with a couple of gas bubbles in the end of the
tail. Having tried a number of treatments in the past that havn’t worked I took
a slightly more drastic approach this time and dropped the temperature from 23°C (73.4°F) down to 18°C (64.4°F) having first isolated the infected animals into a separate
tank. I then left them like this for 4 weeks after which I increased the
temperature slowly up to 21°C (70°F), which it still is. After the second week
the vibriosis had gone completely (and has not returned) and the gas bubbles
were gone after the third week. In all the time the temperature was low the
animals reduced their feeding and it has now increased with the raising of the
temperature and they since gone on to have two broods of fry.

Best wishes,
Neil Garrick-Maidment
Seahorse Project Co-ordinator

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.

One simple way to drop the water temp in your aquarium is to position a small fan so it blows across the surface of the water continually (Giwojna, Oct. 2003). This will lower the water temperature a several degrees via evaporative cooling (just be sure to top off the tank regularly to replace the water lost to evaporation). Leaving the cover/hood and light off on your seahorse tank in conjunction with evaporative cooling can make a surprising difference.

In a pinch, some hobbyists will even freeze plastic bottles 3/4 full of water and float the frozen bottles of water in their tank during the hottest part of the day. If necessary, that may worth trying in your case too, depending on how well your aquarium temp responds to the other measures.

Here are some additional suggestions on cooling down your aquarium from Renée at the org that you may also find helpful:

Some summer tips are:

• Use computer fans (you can wire them to AC adapters… we are making some this weekend for our tanks).

• Use a big ol clip-on-fan or a fan on a stand that you can set close. (Just be mindful of water evap.)

• Float ice containers in the tank (Use water/liquid that you wouldn’t care if it sprung a leak. Those blue lunch/picnic type cooling things are not acceptable IMO…. what if it leaks? It will kill everything. I would recommend using bottled ice water because it will stay frozen even longer than fresh water….. but if you do use fresh water make sure it is water you wouldn’t mind spilling into the tank…. good ole tap water is not acceptable.)

• If you have a hood or canopy on the tank…..keep it off or lifted.

• Cool down the room the tank is in by using a portable or window AC unit. The window units can be pretty cheap.

• If the sun really heats up this room, look into some window tinting. This is what I did when I lived in South Texas. It dropped the room temp TEREMENDOUSLY! (If ya wanna go the cheap method, foil was used in many windows in the city I lived in… wasn’t the prettiest method but it saved many people lives who lived in places without central AC and couldn’t afford well working window units.)

• Shorten your photoperiod…. if possible don’t have the lights on in the hottest past of the day. But at any rate, shorten the amount of hours the lights are on for.

When reducing the water temperature via evaporative cooling, I should also caution you to observe all the usual precautions to prevent shocks and electrical accident when you are using an electric fan or any other electrical equipment on your aquarium, Ricky.

One such precaution is to install an inexpensive titanium grounding probe in your aquariums. That will protect your seahorses and other wet pets from stray voltage and should also safeguard them electrocution in the event of a catastrophic heater failure or similar accident..

But the best way to protect you and your loved ones from electrical accidents around the fish room is to make sure all the outlets are equipped with Ground Fault Circuit Interrupters. And it’s a good idea to make sure all your electrical equipment is plugged into a surge protector as well to further protect your expensive pumps, filters, heaters, etc. from damage. Some good surge protectors, such as the Shock Busters, come with a GFCI built right into them so you can kill two birds with one stone. So when you set up your cooling fan(s) on the aquarium, be sure they’re plugged into a grounded outlet with a GFCI or a surge protector with GFCI protection.

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

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).

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 povidone iodine (brand name Betadine) can also be a useful addition to the other therapies for tail rot we have been discussing. In other words, Ricky, you can substitute Betadine for Wound Control and then treat the affected area of the tail topically just as described in Lisa Coit’s treatment regimen for neosulfex + Wound Control.

Best of luck resolving this tail infection, sir.

Pete Giwojna

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