I’m sorry to hear about the problems with Gas Bubble Syndrome (GBS) your seahorses have been having. Tail bubbles or subcutaneous emphysema (external GBS) usually respond very well to treatment with Diamox (i.e., acetazolamide), and if you don’t want to treat them in the hospital tank, then I would suggest administering the Diamox orally, which is often a more effective mode of delivery anyway.
The easiest way to get your seahorses to ingest the Diamox is to inject the solution of the medication into live feeder shrimp, as discussed below:
Administering Acetazolamide/Diamox Orally
I have found that the Diamox is often more effective when it’s ingested and administering the medication orally allows you to treat the seahorse in the main tank where he’s most comfortable and relaxed.
If you can obtain a small syringe with a fine needle, the acetazolamide solution can simply be injected into feeder shrimp or even frozen Mysis. Mic Payne (Seahorse Sanctuary) used this method of administering Diamox successfully when he had recurring problems with GBD due to maintaining a population of Hippocampus subelongatus in shallow tanks only 16-inches (40 cm) deep:
"Seahorses maintained in this system are susceptible to gas bubble disease. Specimens with bubbles around the eyes or under the epidermis of the tail are readily treated with acetazolamide (Diamox tablets 250 mg). Mix a very small amount of crushed tablet with water and inject it into several glass shrimp that are then frozen. These are then fed to the target animal at the rate of two per day for four days. Bubbles disappear on the second day."
Volcano shrimp or red feeder shrimp from Ocean Rider (iron horse feed) work great for this. If a fine enough needle is used, they will survive a short while after being injected — long enough for their twitching and leg movements to attract the interest of the seahorse and trigger a feeding response.
Leslie Leddo has cured seahorses with tail bubbles and pouch gas using this technique. She found that a 1/2 cc insulin syringe with a 26-gauge needle was ideal for injecting frozen Mysis or live red feeder shrimp. They plump up when injected and ~1/2 cc is about the most of the solution they can hold. There bodies will actually swell slightly as they are slowly injected and excess solution may start to leak out. The 26-gauge needle is fine enough that it does not kill the feeder shrimp outright; they survive long enough for the kicking of their legs and twitching to assure that they will be eaten. So if your Vet or family doctor will prescribe the Diamox for treating your seahorse, ask them also to provide a 1/2 cc insulin syringe with a 26-gauge needle.
If you are using 250-mg tablets, Leslie found that 1/8 of a tablet provides enough Diamox for several days’ worth of injections. In other words, 1/8 of a 250-mg Diamox tablet provides enough of the medication to inject two shrimp daily for about 5 days. So each day, I would take 1/8 of a tablet and shave off approximately 20%-25% of it to make the Diamox solution for that day’s injections. (NOTE: if you are using 125-mg Diamox tablets, adjust your dosage accordingly — that is, start with 1/4 of a tablet and then shave off 20%-25% of it to make the Diamox solution.) Then crush the Diamox you have shaved off and to a very fine powder and dissolve it in a very small quantity of water.
Use the resulting solution to inject two of the live feeder shrimp and feed them to the affected seahorse immediately after injecting them. You don’t want the healthy seahorses to ingest the medicated shrimp, so target feed them to the affected seahorse only.
Diamox doesn’t dissolve especially well in water; there’s always a residue of undissolved material left behind. Try to avoid this residue when you draw up the medicated solution in your syringe, the particles can sometimes clog up the fine bore needle when you are trying to inject the shrimp.
Each day you will have to prepare fresh Diamox solution to inject the shrimp for that day’s treatment, so just repeat the steps above each day. The affected seahorse should show improvement rapidly, with 2-3 days. If not, after you have fed him injected shrimp for 3 straight days, give him a break from the Diamox for a few days and try again. (Diamox can suppress the appepitite, so feed him unmedicated/uninjected shrimp for a few days to keep him eating and help restore his appetite.) Then feed him Diamox-injected shrimp again at the rate of 2 per day for a total of 3 more days, but this time increase the dosage of Diamox slightly (shave off a bit more of the tablet each day when you mix the new Diamox solution).
Since you’ve been having an outbreak of GBS and related disease problems lately, Seagazer, in addition to treating your seahorses, we should run through the factors that are most commonly associated with bacterial infections and gas bubble disease, and then go over some suggestions on how to minimize such health problems in your aquarium.
Disease-causing (pathogenic) bacteria 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, such as Mycobacteriosis or popeye.
A bacterial infection almost always indicates that there is another problem that is stressing the fishes and weakening their immune response (Indiviglio, 2002). In addition to treating the infection itself, the hobbyist must also identify and correct the underlying problem in order to restore health. Check your water quality and aquarium parameters. A water change and general clean up are usually a good place to start.
One of the best ways to prevent bacterial infections 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.
When disease breaks out in an established aquarium it is therefore generally an indication that something is amiss with your aquarium conditions. A gradual decline in water quality is often a precursor of disease (Indiviglio, 2002). Poor water quality is stressful to seahorses. Prolonged stress weakens their immune system. And an impaired immune system leaves the seahorse vulnerable to bacterial, parasitic, viral, and fungal infections to which healthy, unstressed seahorses are immune. As if that weren’t bad enough, there are a number of environmental diseases that are caused directly by water quality problems.
With this in mind, it’s important to review the most common stressors of captive seahorses. These include the design of the aquarium itself. A poorly designed seahorse setup that lacks adequate cover and shelter, or has too few hitching posts, will be stressful to the occupants (Topps, 1999). Seahorses are shy, secretive animals that rely on camouflage and the ability to conceal themselves for their safety and survival. A sparsely decorated tank that leaves them feeling vulnerable and exposed will be a source of constant stress (Topps, 1999). The seahorse setup should have plenty of secure hiding places so they can conceal themselves from view completely whenever they feel the need for privacy. It should be located in a low traffic area away from external sources of shock and vibration.
Needless to say, rapid fluctuations in temperature, pH, salinity and other aquarium parameters must also be avoided. A large aquarium of 40 gallons or more provides much greater stability in that regard than does a smaller setup. The greater the water volume in the aquarium and sump, the more stable the system will be.
Heat stress 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.
It is therefore doubly important to keep seahorses at the proper temperature. Because of the reasons mentioned above and the fact that water holds less and less dissolved oxygen as it warms up, seahorses generally tolerate temps at the lower end of their preferred range much better than they handle temperatures at the upper limit of their range.
Incompatible tankmates are also stressful for seahorses. This includes not only aggressive, territorial fishes and potential predators but also inoffensive species that are restless, active fishes. Seahorses may be uneasy around fishes that are always on the go, swimming tirelessly back and forth.
Other common stressors for seahorses include overcrowding, overfeeding, stray voltage, and a host of issues related to water quality: ammonia or nitrite spikes, high nitrate levels, inadequate circulation and oxygenation, high CO2 levels and low 02 levels, low pH, etc., etc., etc (Giwojna, Jun. 2002).
In short, if hobbyists provide their seahorses with a stress-free environment, optimum water quality, and a nutritious diet, they will thrive and your aquarium will flourish with a minimum of problems. Preventing disease in the first place is infinitely preferable to trying to treat health problems after the fact. Good seahorse husbandry and diligent maintenance will be rewarded; sooner or later, negligence and poor aquarium management will be punished.
When disease breaks out in an established aquarium it is therefore generally an indication that something is amiss with your aquarium conditions. A gradual decline in water quality is often a precursor of disease (Indiviglio, 2002). Poor water quality is stressful to seahorses. Prolonged stress weakens their immune system. And, as we have been discussing, an impaired immune system leaves the seahorse vulnerable to bacterial, parasitic, viral, and fungal infections which healthy, unstressed seahorses easily fend off.
At the first sign of a health problem:
Because diseases are so often directly related to water quality, or due to stress resulting from a decline in water quality, when trouble arises the first thing you should do is to break out your test kits and check your water chemistry. Very often that will provide a clue to the problem. Make sure the aquarium temperature is within the acceptable range and check for ammonia and/or nitrite spikes first. See if your nitrate levels have risen to harmful levels and look for a drop in pH.
Be sure to check your dissolved oxygen (O2) level too. A significant drop in O2 levels (6 – 7 ppm is optimal) is very stressful yet easily corrected by increasing surface agitation and circulation to promote better oxygenation and gas exchange. At the other extreme, oxygen supersaturation is a red flag indicating a potentially deadly problem with gas embolisms (Gas Bubble Syndrome).
If any of your water quality parameters are off significantly, that may well be the cause of the problem or at least the source of the stress that weakened your seahorses and made them susceptible to disease. And correcting your water chemistry may well nip the problem in the bud, particularly if it is environmental, without the need for any further treatment.
Clean Up & Perform a Water Change
After a quick check of the water chemistry to assess the situation, it’s time to change water and clean up. In most cases, the surest way to improve your water quality and correct the water chemistry is to combine a 25%-50% water change with a thorough aquarium clean up. Siphon around the base of your rockwork and decorations, vacuum the top 1/2 inch of the sand or gravel, rinse or replace your prefilter, and administer a general system cleaning. The idea is to remove any accumulated excess organic material in the sand/gravel bed, top of the filter, or tank that could degrade your water quality, serve as a breeding ground for bacteria or a reservoir for disease, or otherwise be stressing your seahorses. [Note: when cleaning the filter and vacuuming the substrate, your goal is to remove excess organic wastes WITHOUT disturbing the balance of the nitrifying bacteria. Do not dismantle the entire filter, overhaul your entire filter system in one fell swoop, or clean your primary filtration system too zealously or you may impair your biological filtration.]
At first glance your aquarium parameters may look great, but there are some water quality issues that are difficult to detect with standard tests, such as a decrease in dissolved 02, transitory ammonia/nitrite spikes following a heavy feeding, pH drift, or the gradual accumulation of detritus. A water change and cleanup is a simple preventative measure that can help defuse those kinds of hidden factors before they become a problem and stress out your seahorses. These simple measures may restore your water quality and correct the source of the stress before your seahorse becomes seriously ill and requires treatment.
That about covers the most common causes of bacterial infections such as snout rot, along with some preventative measures that help to prevent such problems, Tracey. Here’s a list of some of the factors that are commonly associated with Gas Bubble Disease as well as some of the preventative measures aquarists can take to minimize problems with GBD:
Preventing Gas Bubble Syndrome
Gas bubble syndrome, such as subcutaneous emphysema is one stress-related disease that is triggered by various environmental stressors as discussed below. Here are some precautionary measures to observe, when possible, which can help to eliminate problems with GBS:
Preventing Gas Bubble Syndrome
Since GBS is caused by physical factors in the seahorse setup, when the affliction crops up, it’s a red flag that indicates that there’s something amiss with the conditions in your tank. With that in mind, I would like to quickly review some of the preventative measures aquarists can take to minimize problems with Gas Bubble Syndrome:
(1) Aquarium options (Giwojna, Jan. 2004):
Taller is better. When shopping for a seahorse setup, opt for the tall or high model of the largest aquarium you can reasonable afford and maintain. If the tank is too short, male seahorses may not be able to get enough pumping action in as they ascend and descend during courtship displays and mating (the copulatory rise) to flush out their pouches and cleanse them properly (Cozzi-Schmarr, 2003). This can contribute to bloated pouch, a type of pouch emphysema.
As a rule, your seahorses require a minimum of three times their height (total length) in vertical swimming space in order to mate comfortably and help avoid this sort of pouch gas problem.
Other forms of GBS are also believed to be depth related, but the aquarium must be greater than 30 inches deep to provide any significant protection against them, which is not feasible for most hobbyists (Giwojna, Jan. 2004). A depth of at least 3 feet is known to protect the Hawaiian seahorse (Hippocampus fisheri) against GBD (Karen Brittain, pers. com.).
If you’ve had a problem with GBS in the past, look for a tank at least 20-30 inches tall, reduce your water temp to 70-degrees F, and avoid overly tall hitching posts that reach near the water’s surface (Cozzi-Schmarr, 2003). You want to encourage the seahorses to hang out near the bottom in order to take advantage of every inch of depth the aquarium can provide.
(2) Filtration options (Giwojna, Jan. 2004):
Gas supersaturation of the water can occur whenever the dissolved gas pressure in the water is greater than the atmospheric pressure. When that happens, the dissolved gases in the seahorse’s tissues are no longer in equilibrium with the surrounding aquarium water, causing gas to move into the area with lower partial gas pressure — the tissues and blood of the seahorse – and come out of solution, forming gas emboli! Providing proper filtration, circulation, and aeration can prevent this.
Trickle filter (acts as a de-embolizing tower or degassing column).
External filter that returns water as a "water fall."
Sump with strong aeration.
Overflow drains, as opposed to siphon/suction tubes.
Surface agitation to facilitate efficient gas exchange.
Increased circulation and water movement.
Extra airstone(s) just below the surface of the water.
Having a trickle filter, water "falling" into the tank as it’s returned, or strong aeration in the tank or the sump will help off-gas any supersaturated dissolved gases (Giwojna, Jan. 2004). This will also help off-gas a build up of CO2 and the associated pH drop that some tanks experience when the lights go off (Giwojna, Jan. 2004). The off gassing or degassing takes place only at the very air/water interface, so you want to spread the water into very thin sheets and let it be in contact with the atmosphere for an extended period (Robin Weber, pers. com.). That is precisely what a degas column does by trickling water over solid media open to the atmosphere, and if properly maintained and operated, a wet/dry trickle filter can perform the same function (Jorge A. Gomezjurado, pers. com.). For best results, the outflow from a trickle filter should go into a baffled chamber that will allow bubbles to dissipate before they enter pumps or plumbing restrictions (J. Charles Delbeek, pers. com.).
Airstones, air lifts, bubble wands, etc., if submerged deeper than 18 inches.
Subsurface entry of the inflowing or recirculating water.
On small, closed-system aquariums, supersaturation is often due to the entraining of air on the intake side of a leaky pump, which then chops the air into fine microbubbles and injects it into the water (Cripe, Kowalski and Phipps, 1999). Water and air are thus mixed under high pressure and forced into the water column, which can result in gas supersaturation. An air leak in inflowing or recirculating water that enters the tank below the surface can cause the same thing (Cripe, Kowalski and Phipps, 1999). Allowing the water to splash before it enters the tank is a simple way to prevent this from happening. The splashing helps the water to expel excess gas and reach equilibrium with the ambient air pressure (Giwojna, Jan. 2004).
Likewise, airstones, air lifts, bubble wands and the like can cause problems if they are too deep because they will cause gas to dissolve in water to match the ambient pressure (the current atmospheric pressure) PLUS the pressure of the water column above the stone. If they are immersed at a depth greater than 18 inches, the pressure of the water column above them may be sufficient to cause gas supersaturation of the water, especially when there is little atmosphere/water interface (Colt & Westers, 1982). For example, Robin Weber found that airstone submerged in reservoirs 3 feet deep produced excessive gas supersaturation at the Monterey Bay Aquarium. The airstones produced supersaturation at a level of about 104%, and the only cases of GBS she has ever observed at the aquarium occurred in the most supersaturated exhibits. So keep your airstones shallow!
(3) Eliminate stress (Giwojna, Jan. 2004):
Avoid aggressive tankmates.
Install a titanium grounding probe to eliminate stray voltage.
Avoid exposing the seahorse tank to excessive noise or heavy foot traffic.
Use a cork or Styrofoam aquarium pad beneath the tank to deaden vibrations.
Stress has been linked to GBS in seahorses via the following mechanism: chronic or prolonged stress causes changes in the seahorse’s blood chemistry (acidosis), which in turn affects the oxygen-carrying capacity of certain types of hemoglobin, and the reduced oxygen-carrying capacity of hemoglobin can then causes embolisms to form in the blood.
The excess of protons (H+) under acid conditions also causes carbonic anhydrase to shift to producing CO2 from carbonic acid in the bloodstream, and the CO2 that results can likewise lead to gas embolisms under certain circumstances (Giwojna, Jan. 2004).
Mic Payne is one of the professionals who feel GBS is most likely a stress-related affliction. He believes it is often a result of chronic stress due to antagonistic behavior by overaggressive males, particularly if they are overcrowded (Payne, pers. com.). Exposing our seahorses to any type of stress may leave them predisposed to GBS (and vulnerable to many other diseases as well). Reduce the stress levels on our seahorses and we reduce the incidence of GBS accordingly (Giwojna, Jan. 2004).
(4) Maintain optimum water quality (Giwojna, Jan. 2004):
Don’t overfeed and remove leftovers promptly.
Employ an efficient cleanup crew.
Practice sound aquarium management and maintenance.
Monitor the aquarium parameters regularly.
Maintain total alkalinity and keep your pH between 8.1-8.4
Maintain a strict schedule for routine water changes.
When he was experimenting with possible treatments for GBS, Paul Groves (Head Aquarist at Underwater World in Perth, Australia, at the time) was able to produce all the different forms of GBS in a control group of Hippocampus breviceps simply by exposing them to a dirty, bacteria-laden substrate. His seahorse setup was far better than any hobbyist could hope for — an open system with 100% flow through from the ocean and a live sand base, yet all the seahorses in the tank eventually developed GBS (Groves, pers. com.). Males with chronic pouch gas were the first to appear, followed by specimens with internal GBS, and finally subcutaneous gas bubbles appeared on the tails and snouts of the others Groves, pers. com.). The weakness of Paul’s setup was poor circulation, and for experimental purposes, he deliberately allowed fecal matter and uneaten nauplii to build up on the bed of live sand. (Groves found that antibiotics were totally ineffective in treating GBS, but he eventually cured 10 of the 12 affected seahorses using decompression at a depth of 4 meters.)
It is not clear whether stress from the dirty conditions or exposure to such a high density of bacteria triggered the problem in this case, but the lesson is loud and clear all the same — it pays to keep those aquariums clean (Giwojna, Jan. 2004)! If we keep our seahorses setups clean, we will keep our problems with GBS to a minimum (Giwojna, Jan. 2004).
Maintaining the proper pH is especially important for seahorses, since low pH in the aquarium can result in general metabolic acidosis, leading to gas embolisms via the same mechanisms as stress-induced GBS (Giwojna, Jan. 2004).
(5) Water changing precautions (Giwojna, Jan. 2004):
It’s an excellent idea to use Reverse Osmosis (RO) or Deionized (DI) or RO/DI water for your changes because it’s much more pure than tap water. However, water purified by such methods is very soft and must be buffered before it’s used so it won’t drop the pH in your aquarium when it’s added (Giwojna, Jan. 2004).
When mixing saltwater for your marine aquarium, it’s important to fill your container with all the water you will need BEFORE adding the salt mix. In other words, if you are mixing up 5 gallons of new saltwater, fill the mixing container with 5 gallons of water and then add the salt. If you do it the other way around — dump the salt mix in the container and then start filling it with water, the water can become saturated with salt to the point that the calcium precipitates out. This calcium precipitation will turn the water milky and can also lower the pH to dangerous levels (Giwojna, Jan. 2004).
Water changes can also be a problem because of the supersaturation of gases in tap water. Tap water distribution systems are maintained under pressure at all times, both to insure adequate flow and to prevent polluted water from outside the pipes from entering in at leaks. Any additional gas introduced into these pipes (from a leaky manifold, for example) will be dissolved at these higher partial pressures, and will often be supersaturated when it emerges from the tap (Giwojna, Jan. 2004). Also, gases are more soluble in cold water than warm, so when gas-saturated cold water emerges from the tap and warms up in an aquarium, or is warmed up and preadjusted to aquarium temps prior to making a water change, the water can become supersaturated (Giwojna, Jan. 2004). This must be avoided at all costs because gas supersaturation is one of the factors that can contribute to Gas Bubble Disease in seahorses and other fish.
To prevent this, tap water should be allowed to sit for several days beforehand or gentle aeration can be used to remove gas supersaturation before a water change (just make sure your airstones are not be submerged greater than 18 inches while you’re aerating your freshly mixed water; (Giwojna, Jan. 2004)). Some brands of artificial sea salt also produce low levels of ammonia immediately after mixing with water, and aging or aerating the newly mixed water as described above will dissipate this residual ammonia.
Most of the above is mentioned for future reference — I realize there aren’t many modifications you can make after the fact, once your system is already up and running (Giwojna, Jan. 2004). But there are a few things you can try with your existing system that should help.
First of all, whenever you find yourself dealing with an environmental disease such as GBS, a water change is an excellent place to start. At the first sign of GBS, I suggest you combine a 25%-50% water change with a thorough aquarium clean up (Giwojna, Jan. 2004).
Secondly, consider adding an ordinary airstone to your tank, anchored just beneath the surface of the water. That will add surface agitation, extra aeration, and better gas exchange at the air/water interface (Giwojna, Jan. 2004). Unless you’re quite certain your system already has plenty of water movement, it is also advisable to add a small powerhead for extra circulation (Giwojna, Jan. 2004). Seahorses can handle more water movement than most folks realize, and you can always turn it off during feedings. Just screen off the intake for the powerhead as a precaution so it can’t accidentally suck up a curious seahorse (Giwojna, Jan. 2004).
Finally, use shorter hitching posts and holdfasts that will confine your seahorses to the bottom half of the aquarium and reduce the water temperature. Shorter hitching will get the maximum benefit from whatever depth your tank can provide, and lowering the water temperature allows the water to hold more dissolved gases, which can help avoid any tendency toward supersaturation (Cozzi-Schmarr, 2003).
That’s the rundown on the factors that are commonly associated with bacterial infections and problems with gas bubble disease, Seagazer. In addition to treating your seahorses, concentrate on eliminating any of those known stressors or factors discussed above that may have played a role in your particular problem and rehab your main tank with a water change and a general clean up, as described above. Hopefully, that will help you get to the bottom of things.
Best of luck resolving the outbreak of GBS, Seagazer.