gas bubble problem

Dear Helen:

I’m sorry to hear about your male’s recurring problems with gas bubbles. The bubble/bump that has formed on his chest or abdomen and is causing the buoyancy problems is known as subcutaneous emphysema, a pocket or bubble of gas that builds up subdermally. This is an example of external gas bubble syndrome (GBS). Although the subcutaneous emphysema typically form on the tail or snout of the seahorse, they may occur anywhere on its body and I’m pretty confident that’s what you are dealing with now.

Fortunately, this is the easiest form of GBS to cure and subcutaneous emphysema normally respond very well to treatment with Diamox, which you prudently have on hand (very good planning and foresight on your part, Helen). Subcutaneous emphysema are external GBS usually responds well to Diamox when it is administered as a series of baths, but if you’re stallion is still eating, you can also administer the Diamox orally by injecting it into feeder shrimp or even frozen Mysis. I find that Diamox is often even more effective when it is administered orally, which also allows the seahorse to be treated in the main tank where he is the most comfortable, amid familiar surroundings and the company of his tankmates and/or mate.

I will provide you with instructions for both methods of administering the Diamox and you can choose whichever one seems more convenient and best suited for your circumstances, Helen:

Acetazolamide (brand name Diamox) Baths

The acetazolamide/Diamox treatments are extremely effective in the treatment of external gas bubble disease and GBS-induced Popeye, and are helpful in treating internal GBS and hyperinflation of the swim bladder as well, especially when the affected seahorse has stopped eating. In such cases, instead of a pouch flush, a series of acetazolamide baths is used to administer the medication (Warland, 2002).

The baths should be administered in a hospital ward or quarantine tank. Acetazolamide does not appear to adversely affect biofiltration, but it should not be used in the main tank because it could be harmful to inhibit the enzymatic activity of healthy fishes. Treatments involving acetazolamide tablets are still fairly new to the hobby and the most effective dosages and methods for administering the medication are still in the process of being worked out and adjusted, largely by trail and error.

The appropriate amount of the medication to use varies with the size of the seahorse. Also, please note that the dosages given for the acetazolamide baths are correct for a treatment tank containing 8 gallons (30 liters) of saltwater. If you are using a smaller hospital tank, be sure to scale down the dosage to suit the smaller volume of water you are dealing with.

Using the tablet form of acetazolamide (250 mg), crush the required amount to a very fine powder and dissolve it thoroughly in a cup or two of saltwater. There will usually be a slight residue that will not dissolve in saltwater at the normal alkaline pH (8.0-8.4) of seawater (Warland, 2002). That’s perfectly normal. Just add the solution to your isolation tank, minus the residue, of course, at Tracy’s recommended dosage:

RECOMMENDED DOSAGE

Type of Seahorse _____Size of Seahorse ____Acetazolamide (250-mg)
Mini……………………….up to 3 inches……………1/16 tablet per bath
Small species…………. 3 to 5 inches…………….1/8 tablet per bath
Medium species………..5 to 8 inches…………….1/4 tablet per bath
Large species……………> 8 inches……………….1/2 tablet per bath

As you can see, the usual starting dosage for a seahorse size of your 8 inchers is 1/4 of a 250 mg tablet per 8 gallons of water, but treatments with Diamox have since become much more refined, and most people now find that a considerably larger starting dose is more effective in relieving gas bubble disease. For example, most people now recommend one full 250 mg tablet of Diamox for 8 gallons when bathing a seahorse the size of yours, and that’s the dosage I suggest you use in this case, Helen.

Place the affected seahorse in the treatment tank as soon as first dose of medication has been added. After 24 hours, perform a 100% water change in the hospital tank using premixed water that you’ve carefully aerated and adjusted to be same temperature, pH and salinity. Add a second dose of newly mixed acetazolamide and reintroduce the ailing seahorse to the treatment tank. After a further 24 hours, do another 100% water change and repeat the entire procedure until a total of three treatments have been given. About 24 hours after the third and final dose of acetazolamide has been added to the newly changed saltwater, the medication will have lost its effectiveness and the patient can be returned directly to the main seahorse tank to speed its recovery along.

The same 3-day regimen of acetazolamide baths is the preferred treatment for eternal GBS, and Popeye or Exophthalmia as well as internal GBS and hyperinflation of the gas bladder when the seahorse is no longer eating in the medication cannot be given orally..

However, in the case of external GBS or subcutaneous emphysema, also often referred to as tail bubbles, it is usually recommended that the external blisterlike bubbles be lanced prior to the first of the baths (Warland, 2002). This is not strictly necessary and should not be done when the bubbles are located on the head or snout. The bubbles (subcutaneous emphysema) will gradually deflate and disappear on their own as the medication takes affect. Lancing the bubbles does hasten the healing process, and it is important to release the air from any bubbles when they are so large and/or extensive that they cause buoyancy problems or otherwise interfere with the seahorse’s mobility. In your case, Helen, with the subcutaneous emphysema or gas pocket on the abdomen/chest wall of the seahorse, I would NOT attempt to lance it.

Use a fine sterile needle for this and approach each bubble from the side at a very shallow angle, taking extreme care to pierce only the surface of the bubble, not the underlying skin of the tail (Warland, 2002). Once the bubble surface has been pierced, apply gentle pressure to the bubble to deflate it and release any air or fluid inside.

As with pouch flushes, one of the side affects of acetazolamide baths is loss of appetite. Try to keep the affected seahorse eating by plying it with its favorite live foods during and after treatment, until it has fully recovered.

This 3-day regimen of baths is extremely effective in curing external GBS. They also work fairly well in clearing up Popeye. (Exopthalmia can be result from several different causes, and acetazolamide is only effective when GBS is the cause). Internal GBS is generally more difficult to cure, particularly if the seahorse has stopped eating and the acetazolamide cannot be administered orally. I believe this is because internal GBS is difficult to diagnosis until it is well advanced and emboli have already done serious organ damage.

In stubborn cases, the regimen of acetazolamide baths may have to be repeated a second time. Don’t hesitate to increase the dosage if necessary to clear up the symptoms.

As I mentioned, Diamox (the tablet form of acetazolamide) can also be administered orally, as described bubble:

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. He 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 your male has had recurring problem with gas bubbles, Helen, in addition to treating him we should go over some of the risk factors that are known to contribute to GBS and discussed some of the precautions that can help prevent such problems in the future. Gas bubble syndrome, such as the pouch gas and subcutaneous emphysema that has been plaguing your stallion is a 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.

Add:
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.).

Avoid:
Airstones, air lifts, bubble wands, etc., if submerged deeper than 18 inches.
Leaky pumps.
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 overcrowding.
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).

Those simple measures may make a big difference. Just maintain good water quality, add a shallow airstone and perhaps an extra power head to provide better water movement and gas exchange, and keep things cool and you can reduce your risk of GBS considerably (Giwojna, Jan. 2004).

Please take a quick look at the items mentioned above and see if any of them may apply in your case, Helen, and if so take the appropriate measures discussed above.

Best of luck resolving your stallion’s buoyancy problems and subcutaneous emphysema, Helen! Here’s hoping the Diamox cures is recurring problems with GBS once and for all.

Respectfully,
Pete Giwojna