GBD

Dear designs:

I am very sorry to hear about the problems that your female has been having and the difficulty you have experienced in obtaining acetazolamide (brand name Diamox). The Diamox is a prescription medication that is often a challenge for the home hobbyist to obtain.

Are you sure that your female is having a problem with Gas Bubble Disease (GBD)? GBD is rather uncommon in female seahorses, and when it does occur it is typically in the form of gas bubbles that form just beneath the skin (i.e., subcutaneous emphysema) and look much like a blister if you had burned your finger (except that in GBD, the "blister" is filled with gas rather than fluid). The subcutaneous emphysema most often form on the tail of the seahorse and hobbyists typically refer to this condition simply as "tail bubbles." In short, I would expect to see GBD in a female seahorse in the form of discrete bubbles that form just beneath the skin on her tail.

That doesn’t sound like what you are describing when you say that her "tail is bloated." If the tail becomes bloated and enlarged, it is most often due to a bacterial infection rather than a problem with GBD. If the seahorse’s tail was bloated from a buildup of gas, it would be quite buoyant and the seahorse would be having trouble staying at the bottom and swimming normally. Is your female having any problems with positive buoyancy (the tendency to float), designs?

If the swelling of the tail is due to inflammation and infection, then the appropriate response would be to treat the seahorse in isolation using broad-spectrum antibiotics. If you will read the January 25, 2010 post on the first page of this forum titled "Seahorse worry," it discusses the most useful antibiotics for treating tail rot. Those are the same medications and procedures that I would recommend if your female’s bloated tail is the result of a bacterial infection.

This is what I recommend under the circumstances, designs:

Begin treating your seahorse in the hospital tank using the medications and procedures outlined in the "Seahorse worry" post as soon as possible. Use whichever of the antibiotics recommended for tail rot in that post that you can obtain, but begin treating the female immediately.

In the meantime, while she is undergoing antibiotic therapy, you can attempt to obtain the Diamox from the following sources:

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Unfortunately, obtaining Diamox (the tablet form of acetazolamide) can often be a Catch-22 situation for hobbyists. It is a carbonic anhydrase inhibitor — a prescription drug often used for treating glaucoma, hydrocephaly, epilepsy, congestive heart failure, and altitude sickness in humans, so you have to get it from your Vet or perhaps your family doctor. Unfortunately, Veterinarians are often unfamiliar with Diamox — it’s very much a people med and unless you find a Vet that works with fish regularly, he or she will probably never have heard of gas bubble disease or treating it with carbonic anhydrase inhibitors. Many pet owners are on very good terms with their Vets, who are accustomed to prescribing medications for animals, so it’s often best to approach your Vet first about obtaining Diamox despite the fact they may never have heard of it until you brought it to their attention. Your family doctor, of course, will be familiar with such medications and have Diamox on hand but it can sometimes be difficult to get your MD to jump that final hurdle and prescribe it for a pet. Either way, it can be tough to get the medication you need under these circumstances.

However, I would exhaust those possibilities first before I considered an online source for the Diamox. Print out some of the detailed information that’s been posted regarding pouch emphysema and gas bubble syndrome (GBS) on this forum, and how it’s treated using Diamox, and present that to your family veterinarian and/or your family practitioner. Bring photographs of the pony and be prepared to bring the seahorse in for a visit, if necessary. (Veterinarians are prohibited by law from prescribing medications to treat an animal they have not personally seen and examined. If you have had a close personal relationship with your vet over a period of years, they are often willing to bend that rule in the case of fish, but you may well have to bring the affected seahorse in for a quick checkup to get the desired results.)

If not — if neither your Vet or family physician will prescribe Diamox — then there are places you can order Diamox online without a prescription, but save that for a last resort. (You can’t always be certain of the quality of the medications you receive from such sources; in some cases, you even need to be concerned about counterfeit drugs, although Diamox certainly shouldn’t fall into that category.) The medications will take a week or two to arrive, which is troublesome when your seahorse is ailing and needs help ASAP. And, as you know, customs officials can confiscate such shipments, although that very rarely happens with this particular medication.

If you ultimately need to go that route, the following source is the one most seahorse keepers have found works best:

Click here: Inhouse Drugstore Diamox – online information
http://www.inhousedrugstore.com/neurological/diamox.html

They offer 100 tablets of Diamox (250 mg) for around $20 US, but they ship from Canada by mail, which usually takes a little under two weeks for delivery.
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It will take some time to obtain the Diamox this way, but your female can be undergoing antibiotic therapy in the meantime. Diamox can be safely combined with antibiotics, so once the Diamox does arrive, you could treat the female with the Diamox along with the antibiotics. That way it won’t matter whether the underlying problem is a bacterial infection, tail bubbles, or a case in which GBD is complicated by a secondary bacterial infection — you will be treating the female appropriately regardless of which scenario is being played out…

Please let me know when you finally obtain the Diamox and I will be happy to outline the proper procedure for administering it to achieve best results. If it is a case of subcutaneous emphysema, designs, you can take some comfort in the fact that tail bubbles respond particularly well to treatment with carbonic anhydrase inhibitors such as Diamox.

Best of luck treating your female.

Respectfully,
Pete Giwojna

Dear designs:

Okay, if she is floating, then you are quite correct — acetazolamide (brand name Diamox) is the medication that you will need to resolve this problem. You are doing great to keep hand feeding her to provide her with good nutrition during this crisis — hopefully, that could keep her going long enough for you to obtain the Diamox.

Unfortunately, as you have discovered, Diamox is a prescription medication that can be difficult for the average hobbyist to obtain. If you cannot obtain the Diamox from your family veterinarian or physician, then you have three alternatives at this point:

First of all, you can order the Diamox without a prescription from the online source I mentioned in my previous post. In all probability, the medication will reach you without any problems, although it will take about two weeks to be delivered. Because of this delay, that isn’t much help for a seahorse that is already ailing, but many seahorse keepers find it prudent to order the Diamox from this vendor and then keep it on hand in case it has ever needed.

Secondly, you can appeal to other hobbyists on the various seahorse discussion boards and forums and see if one of them can provide you with some Diamox tablets from their surplus. It usually only takes a handful of the Diamox tablets to treat a case of gas bubble disease and once a hobbyist has attained a supply of Diamox from one source or another, the bulk of the medication is typically left over following a treatment regimen. A sympathetic hobbyist may be willing to make some of his excess Diamox available to you.

Finally, you can consider using the recompression/decompression cure to treat your seahorse for GBD by pressurizing it at a depth of 30 inches or more (the deeper, the better), as explained below. The recompression-decompression cure is a good alternative for treating Gas Bubble Disease (GBD) for hobbyists who are having trouble obtaining Diamox for one reason or another. Anyone can set up a simple homemade decompression chamber and be treating their seahorse as soon as they can mix up a new batch of saltwater. I would be happy to run through those procedures again for anyone who finds themselves in this all-two-familiar familiar Diamox dilemma, ponydesigns:

The Recompression Cure for Gas Bubble Syndrome

Recompression simply involves placing the affected seahorses in a flow-through cage or enclosure and immersing them for a period of days at a depth with sufficient water pressure to cause the emboli to dissolve. The increased hydrostatic pressure causes the gas bubbles that have formed within the tissue and blood of the seahorse to go back into solution where they can be resorbed, relieving the problem. (This is why a decompression chamber is used to treat divers for the "bends," caused by nitrogen gas embolisms within the diver’s tissue and blood.) Afterwards, the seahorses are slowly raised back to normal depth/pressure over a period of hours, allowing the total partial pressures of the dissolved gases in the water and the seahorses’ bloodstream to equalize on the way up.

At present, there is no consensus among the professional aquarists who use this method regarding the exact depth and length of immersion needed to effect a cure. I’ve encountered decompression times ranging from 2 days to 10 days and depths ranging from 10 feet in large aquaria (Paul Groves, pers. com.) to over 35 feet at the bottom of the ocean (Bill Stockly, pers. com.), all of which worked equally well. Interestingly, the shortest immersion time was used successfully at one of the shallowest depths (4 meters) and cured seahorses afflicted with all the different forms of GBS (Paul Groves, pers. com.).

While the exact treatment protocol that will produce the best results remains to be determined, everyone whom has tried the decompression cure agrees as to its remarkable effectiveness. It cures external GBS (subcutaneous emphysema, a.k.a. tail bubbles), chronic pouch emphysema (pouch bloat) and internal GBS equally well. In fact, as long as treatment is begun early enough, before the emboli have caused irreversible damage, decompression has a very high cure rate. It is safe, provides the affected seahorses with immediate relief, and works for all forms of GBS.

Of course, the home hobbyist lacks the resources to apply decompression at the sort of depths employed by the professionals. But I am discussing the recompression-decompression cure in some detail for two reasons. First of all, a number of hobbyists have managed to construct homemade decompression tanks and chambers, and other enterprising hobbyists may wish to follow their lead (Lisa Hovis, pers. com.). Homemade decompression devices range from simple tubes of water 6-12 inches in diameter and 4-12 feet tall capped at one end, designed merely to increase hydrostatic pressure, to pressurized wide-mouth bottles complete with pressure gauges and bleeder valves (Lisa Hovis, pers. com.). Secondly, I suspect that when enough data comes in we will find that a depth considerably less than 10 feet and relatively short immersion times will prove to be adequate to resolve most cases of GBS.

For example, while working with the Hawaiian seahorse (Hippocampus fisheri) at the Waikiki Aquarium, Karen Brittain found that all the specimens kept in smaller, shallower aquaria developed subcutaneous gas bubbles within a matter of months, whereas H. fisheri that were maintained in tanks at least 1 meter deep fared much better (Bull and Mitchell, 2002, p37). The Hawaiian seahorse remains pelagic all its life, typically being found at least a mile offshore in deep water, and Brittain speculates that H. fisheri needs to migrate to depths unachievable under normal aquarium conditions to maintain proper physiological balance (Bull and Mitchell, 2002, p37). I think she is absolutely correct. It seems likely that H. fisheri follows a daily vertical migration pattern, perhaps synchronized with the movements of plankton. Her findings suggest that tanks a minimum of 3 feet deep can provide a measure of protection against GBS, and custom-built aquaria of those dimensions are certainly within the realm of the home hobbyist.

This remains a fertile field for future research. It has been suggested that should there be an outbreak of GBS in one of your aquariums, transferring the seahorses to an aquarium at least 3 times as deep can decompress the patients and prevent a recurrence of such problems (Wooten and Waughman, 2004). This suggestion has a lot of merit. Even upgrading to a tank that’s twice as deep would be quite advantageous in terms of GBS prevention. Much work remains to be done to develop decompression guidelines for seahorses and to determine what sort of depth is needed to confer protection from GBS to different species. But when it comes to GBS, two things are certain: deeper tanks are healthier for seahorses and recompression can achieve remarkable recoveries.

In short, many times your best bet to cure internal GBS may be to try a moderate form of recompression to help your seahorse recover. What I have in mind is confining the affected seahorse in a flow-through enclosure at the bottom of a 50-gallon Rubbermaid enclosure 40 inches deep, or something similar, for a period of about 3 days. Once the seahorse is immersed at the bottom of this homemade "decompression chamber," you cannot raise it to the surface again for daily feedings. Since your decompression chamber will have no biofiltration, I would simply fast your seahorse while it recompresses at depth. It can easily go without eating for a few days and that will help eliminate any ammonia spikes in the meantime.

If you decide to try this, be sure to keep your makeshift decompression chamber well-aerated. A shallow airstone anchored just below the surface — NOT at the bottom of the decompression chamber! — to provide surface agitation and oxygenation should suffice.

When the recompression period is finished, raise the seahorse to the surface (or lower the water level in the hydrostatic chamber) gradually, in a series of stages, over a period of several hours, to assure that the patient decompresses completely and the gas emboli don’t reform.

Lighting your homemade decompression chamber isn’t really necessary. Seahorses have outstanding visual acuity and see very well under low light conditions (a couple of species are even said to have adopted nocturnal behavior in the face of heavy fishing pressure), so your seahorse will be able to see well under the ambient light levels that penetrate and 50-gallon bucket. You won’t be feeding the seahorse while it’s undergoing the decompression cure, so it doesn’t need to be able to see well enough to hunt small prey or anything like that, and the darkened conditions may give the seahorse a sense of security and help it relax, since it won’t be feeling so exposed and vulnerable.

If you want to keep an eye on the seahorse periodically while it’s undergoing pressurization, you can just take a quick peek now and then using a flashlight.

When the recompression period is finished, raise the seahorse to the surface (or lower the water level in the hydrostatic chamber) gradually, in a series of stages, over a period of several hours, to assure that he decompresses completely and the gas emboli don’t reform.

One of our other Club members (Christine) recently used this method to cure her seahorse of internal GBS after Diamox baths had been tried unsuccessfully. Here is how Chris described her experience with GBS, and her treatment method with her homemade decompression chamber, in posts to the group:

Hi — After 3 days of diamox Heidi was still buoyant (the diamox did not
seem to have helped at all), and swimming with the tip of her head
sticking out of the top of the water, clearly frustrated with her
situation. I looked at her with a magnifying class, and can’t see any
external signs of bubbles. I also don’t see any signs of bloating or
eye problems.

I followed Pete’s suggestions, took her off the diamox to restore her
appetite, gave her 1 day of rest in the hospital tank with clean water
and Kanamycin. She ate well yesterday and this morning. I rigged up
an inexpensive way of submersing her to 3 times the depth of my 30
gallon display tank. (I priced building a 6 ft deep tank out of an
acrylic tube attached to a base, or acrylic rectangles
attached to a base, and it came out to be anywhere from $250 to $400.
They wanted to charge $175 per linear foot of the acrylic tube thick
enough to safely support a 5 or 6 ft column of water). I’m going to
try the cheap method first, and will build a deeper aquarium if she
needs a greater water pressure.

So-I have her in a ‘critter keeper’ (small plastic container with a
lid that has slots in it and a viewing window in the center) with 2
soft rubber hitching posts. The lid has 4 large criss-crossed rubber
bands on it just in case the lid comes off. I made sure there weren’t
any bubbles underneath the critter keeper or underneath the little
clear viewing lid on the top. I bought a 50 gallon rubbermaid bucket
which gives a water depth of 3 1/2 ft when filled. The critter keeper
is inside a 5 gallon white bucket weighted down with a signature
coral, with a rope tied to the bucket handle (made it easy to lower
into the big bucket). I lowered her slowly this morning, and she
seems fine (not pinned against the lid of the critter keeper, and she
is able to go between the 2 hitching posts). I have an airstone going
at the surface of the deep bucket, as Pete suggested. I can see her
with a flashlight. Her breathing looks normal.

I filled the 50 gallon bucket yesterday with the shower! and let it
‘degas’ for one day (also to make sure that it didn’t spring a leak.
It is in the bathtub). The water temp is 70 degrees. I matched the
specific gravity and ph of the hospital tank.

Heidi is going to remain there for 2-3 days, as per Pete’s suggestion.
After that, I will bring her up very slowly (or unload the water from
the big bucket very slowly). I hope this works! Our big bathroom has
been completely taken over with buckets, hospital tank, salt mix, etc.
Wish us luck!
Chris

And here is Christine’s follow-up message after the recompression-decompression treatment was completed:

Hi Pete and Everybody, Heidi is okay! No more floating. I unloaded
the water from my makeshift compression chamber very slowly, as per
Pete’s suggestion, rather than pulled up the critter keeper from the
bottom (much safer to unload the water). I then transferred the
critter keeper she was in to a 5 gal bucket of clean saltwater,
and she swam out when I opened the lid. I decided to do a water
change in the main tank before putting her back in, and used the water
I pulled out of the main tank (74 degrees) to warm up the water she
had been in (70 degrees) to help re-acclimate her to the main tank.
She is eating and swimming as normal, back to her aggressive self with
the turkey baster and Mysis. She is very happy to be back in the
display tank, and is enjoying swimming all around, once again
neutrally buoyant. She was sooo happy to see her favorite coral
colored fake coral. Her color is going back from being dark brown
(her under stress color) to light brown/gold today. I hope to see
her go back to her coral color soon. Thanks for your help Pete!

I hope I never again have a SH with the floaties!
For the record, she was in a critter keeper inside a 5 gal bucket
weighted down with a fake (Signature) coral at the bottom of 40 inches
of water in a Rubbermaid 50 gallon bucket (on wheels-a new bucket). I
had an airstone at the top as per Pete’s instructions. She was in for
2 1/2 days.
Chris

For best results, the decompression sure is often combined with antibiotic therapy. It is a simple matter to administer a regimen of antibiotics while the seahorse is submerged at the bottom of the 50-gallon Rubbermaid bucket. (Just don’t perform any water changes while the seahorse is undergoing recompression-decompression.) This would help prevent any secondary infections which are often associated with GBS or stress, and would also cover all the bases if you suspect the underlying cause of your seahorse’s positive buoyancy may be due to a bacterial infection.

For the antibiotic therapy, kanamycin, neomycin, and nifurpirinol are the antibiotics I prefer. I would recommend using two of them (i.e., kanamycin/neomycin or nifurpinol/neomycin) in combination for even greater efficacy, as described below:

Kanamycin

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.

nifurpirinol (Furanase)

Nifurpirinol is a nitrofuran antibiotic that is the active ingredient in many commercial preparations designed for use in the aquarium. It is stable in saltwater and rapidly absorbed by fish, making it the preferred treatment for fungal infections in seahorses (Burns, 2002). Nifurpirinol is photosensitive and may be inactivated in bright light, so use this medication only in a darkened hospital tank.

Nifurpirinol may be combined with neomycin (see below) to produce a potent broad-spectrum medication that’s effective against both fungus and bacteria. Nifurpirinol/neomycin is therefore a great combination to use when you’re not certain whether the infection you are treating is fungal or bacterial in nature.

neomycin sulfate

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.

One other thing to keep in mind is water temperature. Since you’re homemade decompression chamber is unheated, the water temperature will gradually fall over the three-day treatment period. This is fine and to be is expected — and even beneficial in many respects — but it does mean that once the decompression period is over, you may have to acclimate the seahorse for temperature before returning the patient to the main tank.

In short, designs, you might want to consider ordering the Diamox from the outline vendor I suggest and then pressurize the affected stallion in a homemade decompression chamber as described above while you are waiting for the medication to arrive.

The preventative measures were GBD we have discussed on this forum on several occasions can help stabilize future problems with gas bubble disease, but they won’t reverse the damage that has already been done or cure an ongoing problem with GBD.

Best of luck restoring your female to neutral buoyancy again, designs.

Respectfully,
Pete Giwojna

Dear ponydesigns:

I’m very sorry to hear that you lost your female before you could obtain any Diamox or try decompressing her — all my condolences on your loss!

A widowed seahorse can certainly be traumatized by the loss of its mate. But although it can be stressful for a pair-bonded seahorse to lose its partner, a widowed seahorses won’t go on a hunger strike and starve itself to death, or die of a broken heart or loneliness, or anything of that nature.

Even so, captive-bred seahorses like yours are highly gregarious animals that very much appreciate the company of others of their kind, so it is a good idea to provide your widower with a prospective new mate. If you purchase a single female for your stallion, the chances are excellent that they will eventually pair-up and breed.

The genetic imperative to reproduce is very strong in Hippocampus, to say the least. For example, solitary males often go through the motions of courtship when there are no other seahorses present in their aquarium (Abbott, 2003). They may court their own reflection and sometimes even direct their courtship displays toward their keepers (Abbott, 2003). If no females are present, over-stimulated stallions will sometimes soothe themselves by basking in the air stream from an airstone, content with the tactile stimulation provided by the gentle barrage of bubbles. They may even flirt with inanimate objects. If all else fails, a hitching post may actually suffice as a suitable surrogate when no better alternative is available (Abbott, 2003)!

Same-sex courting displays (both male and female) are also common when no member of the opposite sex is present. Under such circumstances, these passionate ponies are not picky about their partners — males will dance with other stallions and frustrated females will sometimes flirt with other fillies (Abbott, 2003)!

Captive-bred seahorses are far more social and gregarious than their wild conspecifics, so it’s not surprising that cultured seahorses are particularly irrepressible in that regard. They seem to court constantly and the urge to procreate dominates their lives. If given a choice, they are apt to change partners often, and courtship, flirting and dancing are the activities that consume their days. Long before they are sexually mature, juvenile males will spend hours dancing with one another, just horsing around, practicing their moves and perfecting their technique for the real thing to come. Likewise, mature males often compete actively and aggressively with one another through harmless pouch displays and tail-wrestling tug-o-wars whether or not there is a female nearby to appreciate their efforts.

As Carol Cozzi-Schmarr of Ocean Rider, the premier aquaculture facility in Hawaii, puts it, "As far as mating is concerned, it is important to understand that because these sea horses are farm raised and therefore "domesticated" they will be breaking a lot of the rules previously established for wild caughts. They will require less horizontal as well as vertical space and they no longer tend to be shy or picky! In other words they will show off to and mate with whomever they can, even if it means leaving behind the sea horse they mated with last time! It does not matter if their selected partner appears too short or too tall or of a different color or even of the same sex!! They want to dance and court more than anything else (Cozzi-Schmarr, May 2002)!!"

However, there is no need to replace your female seahorse immediately, ponydesigns. When a wild seahorse loses its mate, evidence suggests that it does not immediately seek out a new mate. Rather, a widowed stallion typically waits one complete breeding cycle in the hope that it’s missing mate will reappear before it abandons its territory to search for another suitable partners. (One breeding cycle is 2-4 weeks, depending on the species. If you wish, think of this delay as a "mourning period" of sorts.)

But once this wait is over, field research indicates that, in the wild, a widowed seahorse typically pairs up with the next unmated seahorse of the opposite sex it encounters. In this case, that would be the new female you introduced to your tank, so don’t hesitate to obtain a solo mare for your male at some point, but he will probably not be ready to accept a new partner until a month or so has passed.

In the meantime, you may want to concentrate on correcting any conditions in your seahorse tank that may be conducive to problems with gas embolisms. Gas bubble syndrome (GBS) is a mysterious, widely misunderstood affliction that can take on many different incarnations. As you know, gas bubble syndrome is believed to be caused by gas emboli forming within the tissue of heavily vascularized portions of the seahorse’s anatomy — the placenta-like brood pouch of males, the eye, the muscular prehensile tail — and it can take several different forms depending on where the bubbles or emboli occur. When it occurs in the brood pouch of the male, chronic pouch emphysema or bloated pouch results, leading to positive buoyancy, which is by far the most common form of GBS. When it occurs in the capillary network behind the eye (choroid rete), Exopthalmus or Popeye results, and the eye(s) can become enormously swollen. When it affects the capillary network of the gas bladder (the rete mirabile), hyperinflation of the swimbladder occurs, resulting in positive buoyancy. When it affects the tail or snout, external gas bubbles (i.e., subcutaneous emphysema) form just beneath the skin and look like raised blisters. When intravascular emboli occur deep within the tissue and occlude blood flow, generalized edema results in the affected area. Or extravascular emboli may cause gas to build up within the coelom, often resulting in positive buoyancy and swelling or bloating of the abdominal cavity (internal GBS).

Different parts of the body can thus be affected depending on how the
initial gas emboli or micronuclei form, grow and spread. During an
episode of GBS, bubbles may initially form in the blood
(intravascular) or outside the blood (extravascular). Either way,
once formed, a number of different critical insults are possible.
Intravascular bubbles may stop in closed circulatory vessels and
induce ischemia, blood sludging, edema, chemistry degradations, or
mechanical nerve deformation. Circulating gas emboli may occlude the
arterial flow or leave the circulation to lodge in tissue sites as
extravasular bubbles. Extravascular bubbles may remain locally in
tissue sites, assimilating gas by diffusion from adjacent
supersaturated tissue and growing until a nerve ending is deformed or
circulation in nearby capillaries and vessels is restricted. Or,
extravascular bubbles might enter the arterial or venous flows, at
which point they become intravascular bubbles. Extravascular bubbles
can thus become intravascular bubbles, and vice versa, via diffusion
and perfusion. This is important because it means that under certain
conditions extravascular seed bubbles or micronuclei can enter the
bloodstream and migrate from their birth site to other critical areas
as intravascular bubbles. If untreated, the gas bubbles worsen and
the condition is fatal.

The mechanisms by which the gas emboli can spread and grow, and the type of insults that can result are therefore fairly well known, but the etiology of GBS is otherwise still poorly understood, and there are many theories as to what causes the gas embolisms to form in the first place. Nitrogen gas supersaturation of the water, the unique physiology of the male’s brood pouch, malfunctions of the pseudobranch or the gas gland of the swim bladder, stress-related changes in blood chemistry that affect the oxygen-carrying capacity of hemoglobin, infection with gas-producing bacteria — all these and more have been advanced as mechanisms that could trigger the formation of the gas embolisms at some point. Very likely GBS has multiple causes, but most experts now believe it is due to physical conditions in the seahorse tank rather than any sort of pathogen, and I would be happy to share my thoughts on the matter with you, for whatever it’s worth.

For starters, let me stress that if it’s very unlikely that any sort of disease organisms or pathogen causes GBD. It is not at all contagious and does not appear to spread from seahorse to seahorse. To my knowledge, no one has ever been able to isolate a pathogen from the marsupium of the male with pouch emphysema or from the subcutaneous emphysema that characterize seahorses with tail bubbles. If bacteria play a role in GBD, I am confident it is only as a secondary infection.

In other words, gas bubble syndrome is not a disease that seahorses contract after being exposed to a pathogen of some sort, but they will often develop the condition when kept in a system that exposes them to gas supersaturation, insufficient water depth, stress, inadequate water circulation, a bacteria-laden substrate or other environmental factors conducive to the formation of gas emboli. In other words, it is an environmental disease, triggered by certain conditions within the aquarium itself. In my experience, the environmental triggers that are most often associated with GBS are as follows:

1) Insufficient depth (aquaria that are less than 20 inches deep are very susceptible to GBS, and the taller the aquarium is, the more resistant it will be to GBS).

2) Gas supersaturation of the aquarium water, which can lead directly to the formation of gas emboli within the blood and tissues of seahorses.

3) Changes in the seahorse’s blood chemistry (i.e., acidosis). Anything that tends to acidify the blood of the seahorses can result in GBS, including stress, low levels of dissolved oxygen and/or high levels of CO2, and low pH in the aquarium water, among other factors.

Maintaining reduced specific gravity and lower water temperature are good ways to minimize future problems with GBS due to gas supersaturation, but there are a number of other things to keep in mind in that regard as well.

For example, tall aquariums minimize problems with GBS because the deeper the water and the greater the hydrostatic pressure, the more dissolved gases the water (and the seahorse’s blood) can hold in solution. By the same token, the shallower the aquarium and the less water pressure there is, the less dissolved gases the water can hold and the more likely gas is to come out of solution and form gas emboli (i.e., seed bubbles) in the blood and tissues.

The point is that the greater hydrostatic pressure at increased depth is known to protect seahorses against GBS, whereas the reduced hydrostatic pressure in shallow aquaria is known to be conducive to gas bubble syndrome. I have found that GBS is a very common problem for seahorses in home aquariums that are less than 24-inches tall, whereas there is considerable evidence that tanks 3 feet deep or more provide a measure of protection against GBS. This is because the gas emboli that cause GBS form more readily at reduced hydrostatic pressure, and will go back into solution again if the hydrostatic pressure is increased sufficiently, and obviously the deeper the aquarium the greater the hydrostatic pressure at the bottom of the tank. (In fact, seahorses with GBS can often be cured by submerging them at depths great enough to recompress them (> 10 feet) and cause the gas to go back into solution.)

I know you’ve seen this material before, ponydesigns, but it never hurts to review it again, so here is some information that reviews the most common aquarium stressors, among other causes of GBS, and discusses some simple methods for minimizing problems with GBS. Please look it over closely and see if any of these factors may have contributed to this problem in your case:

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). As an example, a water 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 68°F-72°F, reduce the specific gravity of the aquarium water, 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 help prevent this.

Add:
Trickle filter (acts as a de-embolizing tower or degassing column in a limited fashion).
External filter that returns water as a "water fall" or a canister filter with a spray bar return positioned so that it roils the water surface.
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 and surface agitation 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 and photosynthesis has no longer taking place (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 or biowheel filter can often perform the same function to a limited extent (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., that are submerged deeper than 18 inches.
Leaky pumps.
Subsurface entry of the inflowing or recirculating water.
Protein skimmers that generate a bubble column by injecting air under pressure at depth.

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 low-level 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 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!

Protein skimmers that inject air under pressure at depth, or produce bubbles a foot or more below the surface, can be problematic for seahorses and other fish fry again because that can cause gas to dissolve in the aquarium water at ambient pressure (the current atmospheric pressure) PLUS the pressure of the water column above the bubbles. Under certain circumstances, this can cause low level gas supersaturation of the water and contribute to problems with gas bubble disease (Colt & Westers, 1982) in syngnathids (i.e., seahorses and pipefish). Other skimmers can also cause problems by releasing clouds of microbubbles into the aquarium, which is unsightly and can contribute to certain forms of gas bubble syndrome in seahorses and pipefish such as subcutaneous emphysema, chronic pouch emphysema, Exopthalmia, and hyperinflation of the gas bladder under certain circumstances. (Problems can result if the microbubbles are drawn into the filters or water pumps and pressurized in the process.) So if you have had problems with GBS in a home aquarium filtered by a protein skimmer, consider removing or disabling the protein skimmer to determine if that makes a difference for the better…

(3) Eliminate stress (Giwojna, Jan. 2004):

Avoid overcrowding.
Avoid aggressive tankmates.
Avoid heat stress and temperature spikes.
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.
Gradually reduce the water temperature to increase the amount of dissolved gases it can hold.
Reduce the salinity in the main tank to increase the amount of dissolved gases the water can hold.

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 by pressurizing them 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 contribute to the acidosis under certain circumstances, leading to gas embolisms via the same mechanisms as stress-induced GBS (Giwojna, Jan. 2004).

Likewise, it’s important to remember that the warmer the water, the less dissolved oxygen it can hold. Elevated water temperatures increase the metabolism of your seahorses, and therefore their consumption of oxygen, at the same time that the rise in temperature is reducing the amount of dissolved oxygen in the water. That creates a dangerous situation for seahorses and may well result in respiratory distress and rapid, labored breathing, as well as contributing to asphyxia and gas supersaturation under certain circumstances. Reducing the water temperature will increase the amount of dissolved oxygen and other gases the water can hold before it becomes saturated, reducing the chances of gas supersaturation (hence GBS) and hypoxia accordingly.

There is also an inverse relationship between salinity and dissolved oxygen. The higher the specific gravity or salinity, the less dissolved oxygen (and other dissolved gases) the water can hold. By the same token, the lower the salinity or specific gravity, the more dissolved gases the water can hold. Sometimes the specific gravity in a seahorse tank can creep up unbeknownst to the aquarist due to evaporation of the aquarium water, and the higher the specific gravity gets, the lower the dissolved gas levels in the aquarium will be and the greater the chances that the aquarium water could become supersaturated with dissolved gas. Lowering the specific gravity in the home aquarium as to at least 1.020 is a good way to eliminate such potential complications. Seahorses will be perfectly comfortable at a specific gravity of 1.015-1.017. Reducing the salinity will help prevent potential problems with gas supersaturation and therefore GBS.

(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 are higher partial pressures, and will often be supersaturated when it emerges from the tap (Giwojna, Jan. 2004). Also, as we have previously discussed, 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 Syndrome 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 for hobbyists that have well-established seahorse tanks — 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).

Thirdly, I recommend that home hobbyists who have had a problem with GBS in the past reduce the salinity in their seahorse tanks to at least 1.020 in order to increase the amount of dissolved gases the water can hold before it become saturated. Reducing the specific gravity to 1.015-1.017 is even better in most cases, providing you aren’t keeping live corals or delicate invertebrates in your seahorse tank. Likewise, reduce the water temperature in tanks with a history of GBS to around 68°F-72°F in order to increase the amount of dissolved gases the water can hold before it become saturated. Both these simple measures will help prevent gas supersaturation and reduce future problems with GBS accordingly.

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 posts will get the maximum benefit from whatever depth your tank can provide, and lowering the water temperature and specific gravity 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, provide your seahorses with the stress-free environment, add a shallow airstone and perhaps an extra power head to provide better water movement and gas exchange, remove your protein skimmer as a precaution, keep things cool and reduce the water temperature in your seahorse tank, and you can reduce your risk of GBS considerably.

That’s my thinking with regard to preventing GBS, ponydesigns. I suspect that very few of the factors mentioned above apply to your seahorse setup, sir, but they are common problems for many home aquarists.

Best of luck finding a new mate for your stallion when the time comes, ponydesigns! Here’s hoping your troubles with gas bubble syndrome are soon a thing of the past.

Respectfully,
Pete Giwojna