Re:bloated pinto

Dear hobbyist:

I’m sorry to hear about the loss of your Sunburst and the problem you’re Pinto has developed. If there was redness and inflammation at the tip of your Pinto’s tail, indicating a possible bacterial infection, that it was a good idea to treat him with antibiotic therapy, and neomycin combined with triple sulfa is generally a good broad-spectrum combination of antibiotics to start with.

However, I am a little mystified as to why you would be treating your Pinto with Diamox (the tablet form of acetazolamide) for the condition you described. Diamox is a carbonic anhydrase inhibitor that works well in cases of Gas Bubble Syndrome (GBS). It is appropriate when your seahorse’s symptoms include recurring pouch emphysema, internal GBS (swelling of the coelom or abdominal cavity accompanied by positive buoyancy), subcutaneous emphysema or tail bubbles, certain cases of exophthalmia (Popeye), and hyperinflation of the gas bladder.

Collectively, all of these conditions are known as Gas Bubble Syndrome or GBS for short, and they all result from gas bubbles 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. As described above, GBS 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 GBD. 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 gas bladder occurs, resulting in positive buoyancy. When it affects the tail or snout, external gas bubbles 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 GBD). If untreated, the gas bubbles worsen and the condition is fatal.

Your Pinto has none of those symptoms. When a seahorse’s pouch becomes swollen and enlarged, but his normal equilibrium is not disrupted and he is not bothered by buoyancy problems (i.e., the tendency to float), then you can be confident that his bloated pouch is not due to GBS. In such cases, the pouch is generally filled with fluid rather than gas, just as you suspect. This can be marsupial fluid if the seahorse is pregnant, aquarium water if the seahorse is courting (when courting, males will inflate their pouches with water to the bursting point in impressive pouch displays known aptly as "Pumping" and "Ballooning"), or edema in the case of ailments such as ascites, which is a symptom of bacterial infections and/or kidney problems.

I imagine that you added Diamox to your treatment regimen in the hope that it would act as a diuretic and relieve the buildup of fluid in your Pinto’s pouch. It is a common misconception that the beneficial effects Diamox produces when treating GBS is due to its effect as a mild diabetic, but that is entirely incorrect. It is true that Diamox increases the excretion of bicarbonate from the kidneys, and thus acts as a weak diuretic, but it cures GBS through an entirely different mechanism, as described below:

Diamox or acetazolamide is a carbonic anhydrase inhibitor, nothing more. Carbonic anhydrase is simply a zinc-containing enzyme that catalyzes the following reversible reaction, which helps change carbon dioxide into bicarbonate ion, a form of CO2 that is more easily carried in the bloodstream, or vice versa:

CO2 + H2O <—–> H2CO3 <—–> HCO3- + H+
carbon dioxide….carbonic acid…. bicarbonate ion

As long as the body’s normal equilibrium is maintained, all is well, but when imbalances drive this reaction too far in either direction, gas emboli can result, causing intravascular and/or extravascular gas bubbles to build up in the seahorse’s blood and tissue as previously described. Diamox inhibits this enzyme, thereby decreasing the production of bicarbonate and preventing the formation of such gas emboli, thereby allowing the body to restore its normal equilibrium..

Now, due to its properties as a mild diuretic, Diamox is sometimes used to treat excess fluid retention in humans. I suspect you may be using the Diamox in a similar capacity, hoping that it may resolve the excess fluid retention you believe may be causing your Pinto’s pouch to inflate with fluid. While this works well enough in people and other animals that lack a swimbladder, it can be very harmful to treat fishes with Diamox for this purpose. This is because seahorses and other fishes rely on the mechanism catalyzed by the enzyme carbonic-anhydrase in order to maintain the proper gas balance in their swim bladders.

As a result, administering Diamox to seahorses that are not having problems with gas bubbles (GBS) can have dire consequences. Inhibiting carbonic-anhydrase in healthy seahorses and disrupting the reaction outlined above can alter their blood chemistry and blood gases, and severely impair their ability to inflate their swimbladders. This can be quite dangerous and treating a seahorse that does not have GBS with Diamox can make it seriously ill. Disrupting the seahorse’s blood chemistry and blood gases this way can literally have life-threatening consequences.

In short, Diamox is appropriate for treating seahorses with symptoms of GBS, but it is contraindicated and can do more harm than good if administered to seahorses that are not having problems with positive buoyancy or gas bubbles.

Based on the symptoms you have described, it does not sound to me like your seahorse is suffering from GBS, and I would therefore discontinue treating your Pinto with Diamox immediately. Aside from disrupting blood chemistry and disrupting the function of the swimbladder, Diamox also suppresses appetite, and it’s important to provide your seahorse with good nutrition while he is fighting off an illness. If his pouch is loaded with excess fluid, a condition known as ascites, it is most likely a bacterial problem and antibiotic therapy, rather than Diamox, is probably the best treatment option.

You mentioned that, in addition to the turgid pouch, the tail of your Pinto also seems to becoming somewhat swollen. We sometimes see such swelling as a result of bacterial infections such as Vibriosis. Badly infected fishes may develop a distended, fluid-filled abdomen due to internal bacterial infection (septicemia) of the kidneys, liver or intestinal tract (Dixon, 1999). This disrupts the normal circulation of the blood and lymph, causing fluids to accumulate in the intestine and abdominal cavity (Dixon, 1999), and in the case of a seahorse, possibly within the heavily vascularized brood pouch and prehensile tail as well.

Neomycin + triple sulfa has been found to be an effective treatment for some Vibrio infections, and you should complete the full 10-day treatment regimen of these antibiotics. It may take several days to notice any improvement. Sometimes the patients don’t respond for a full week. However, now that you’ve begun the treatment regimen with neomycin + triple sulfa, it’s important that you complete the full 10 days of treatment regardless of whether or not it seems to be helping. Otherwise, if you cut treatment short, the bacteria may develop resistance to neomycin and triple sulfa, which can have very unfortunate long-term consequences.

If the neomycin + triple sulfa doesn’t seem to be helping, after 10 days you can consider trying a different regimen of antibiotics instead. For example, Chloramphenicol is often very effective in treating Vibrio infections. It can be given orally or used as a bath (Prescott, 2001c). Therapeutic baths lasting 10-20 hours are administered in a chloramphenicol solution consisting of 40 mg per liter of water (Prescott, 2001c). If the seahorse is still eating, the chloramphenicol can also be bioencapsulated by gut loading feeder shrimp or ghost shrimp with flake food soaked in the antibiotic solution. Even if the affected seahorses does not eat, feeding medicated shrimp to its tankmates is a good way to prevent this contagious disease from spreading to the healthy seahorses (Prescott, 2001c).

As mentioned above, Chloramphenicol can be used to treat Vibriosis at 40 mg/ litre of water (which comes out to about 150 milligrams per gallon) in a bath for 10-20 hours. It is important to watch the quality of the water, and if it starts to become turbid, the water must be changed. It is best to treat in a separate tank. In stubborn cases, a series of such baths may be necessary to resolve the problem, in which case a complete water change should be performed before the medication is redosed.

Chloramphenicol can also be used as an additive to the feed, if the fish are still eating (all to often in a major infection they will refuse to eat, but this treatment may be most useful in preventing the horizontal spread of the infection). When used as an addition to the feed use 500 mg per 100 gram of feed. (In the case of seahorses, the flake food medicated with chloramphenicol in this way would first be bio-encapsulated in live feeder shrimp, which would then in turn be fed to the seahorses.)

If you can obtain the chloramphenicol from your veterinarian, be sure to be very careful when handling it. Remember, in a few rare individuals exposure to chloramphenicol can cause a potentially fatal side effect (aplastic anemia). These are rare cases and almost always involve patients who were being treated with the medication, but I would use gloves when handling it as a precaution and if you crush crush up tablets of chloramphenicol, be very careful not to inhale any of the power.

You might also try ciprofloxacin for Vibrio infections. It can be obtained as a fish medication from the following online source, and the instructions/dosage for treating with it should be included in the package:

Click here: animals alive ltd.
http://www.animalsaliveltd.com/catalog/index.php?cPath=98_99

But before you resort to a shotgun approach of trying various broad-spectrum antibiotics to see if you can find one that your Pinto responds to, I would like you to consider performing a needle aspiration of the fluid in his pouch, and then sending a sample of the aspirate to Dr. Martin Belli to analyze at his lab. He will be able to culture the aspirate and growout any bacteria in the fluid, which will allow him to test those bacteria for sensitivity to various antibiotics. That way, Marty can advise you as to which particular antibiotic will be most effective in treating this condition.

Consult Dr. Belli online before you send him any samples, however. Just send a PM to Labdoc and outline your problem and what you propose to do regarding the needle aspiration If you perform a needle aspiration, save a portion of the fluid you aspirate in a sterile vial or a small sterile test tube with a rubber stopper, and ship it to Dr. Belli via overnight delivery if he agrees to analyze it and perform the necessary cultures.

A needle aspiration is a very straightforward technique that simply involves inserting a hypodermic needle through the side of the pouch, tapping into the pocket(s) of trapped gas or fluid, withdrawing the plunger on the syringe and removing the fluid or gas. If you have never done a needle aspiration before, I know it sounds a bit gruesome, but it is a surprisingly painless procedure for the seahorse and is often easier and less stressful for both the aquarist and the patient than performing pouch flushes or repeatedly massaging the pouch. Not only is a needle aspiration less traumatic, as a rule, but it is also often more effective in removing the trapped gas and relieving the problem. And it is the best way to relieve fluid build up in a case like yours.

A needle aspiration could be especially revealing for your Pinto, since I wouldn’t necessarily rule out pregnancy under the circumstances. Pintos have been known to breed with Sunbursts, and Pintos typically produce very large broods of fry. The gestation period for Pintos can be up to 30 days, so if your Pinto was courting your Sunburst shortly before his pouch began to swell, pregnancy could still be a possibility. If your male’s pouch has expanded almost to the point of bursting, yet he is not having problems with positive buoyancy, he may well have something in his pouch other than fluid. He could be carrying a brood of embryonic young or fetal fry in addition to fluid retention. Stress, or anything else that disrupts the key hormones that maintain the pregnancy and trigger parturition, may have prolonged his pregnancy abnormally and delayed delivery.

So if you perform a needle aspiration on your Pinto, the hypodermic may also extract fluid from the marsupium and/or yolk from ova implanted within the lining of the pouch. That can indicate whether your male is pregnant or possibly has another problem in addition to fluid retention or ascites. In fact, for those very reasons, it is standard operating procedure for the pros to perform a needle aspiration on males with buoyancy problems for diagnostic purposes, as described by Dr. Marty Greenwell below:

"As noted above, there are several potential etiologies when an animal is experiencing buoyancy problems. If the pouch appears asymmetrically distended or symmetrically distended with attendant buoyancy problems, a percutaneous fine needle aspirate should be performed on the pouch contents. Any fluid aspirated should be dried and stained with Wright-Giemsa stain, Gram stain, and acid-fast stain. The pouch can also be flushed with sterile saline and the aspirate sent for culture." ("Syngnathids Health Management," Martin G. Greenwell, Shedd Aquarium — Seahorse Husbandry in Public Aquariums: 2005 Manual.)

Remember, you’re not trying to skewer the seahorse — the wall of the pouch consists of four thin layers of epithelial and connective tissue, so you don’t need to insert the needle very far in order to penetrate the membranes of the marsupium and reach the central cavity of the pouch.

I realize performing a needle aspiration seems like an intimidating procedure, but in actual practice, it is much easier than it sounds. In fact, because their small size makes it so difficult to burp the pouch of a dwarf seahorse, a needle aspiration is often the preferred technique for releasing pouch gas from pigmy males (Hippocampus zosterae). For instance, Kirk Strawn is an expert on H. zosterae who often performs needle aspirations or even rudimentary surgical procedures to release pouch gas from male dwarves, and he reports that the delicate dwarfs are none the worse for wear afterwards:

This is how Kirk Strawn describes pouch gas problems in pygmies in an article called ”Keeping and Breeding the Dwarf Seahorse” (Aquarium Journal, October 1954: pp 226-228.): ”Unguarded airstones disrupted many courtships. A courting male pumps up his brood pouch with water until it appears ready to burst. When this action occurs in the stream of bubbles above an air stone, a bubble is likely to be sucked into the pouch producing a disastrous effect on courtship. The male swims over to meet the female. When the air bubble in the brood pouch shifts, he loses balance and floats tail first to the surface. With great effort he swims down to a perch and wraps his tail around it. Firmly anchored, he resumes an upright position. The female comes over and wraps her tail around his. When she moves away, he follows, loses his balance, and shoots to the surface. Finally the pair give up trying to breed. These bubbles remain in the pouch unless removed. In nature death would surely result either by the male’s being washed ashore or from its being exposed to predators. In the aquarium a floating male can live indefinitely.”

Strawn then goes on to describe how this recurring problem can be remedied: ”…removing the bubble by inserting a needle into the opening of the pouch…is a more difficult operation on the little dwarfs. It is more easily accomplished either during courtship or following the delivery of young–at which times the opening to the pouch is dilated. Inserting a needle through the entrance of the pouch does not ruin a male for future breeding. A male kept away from females from February until June had bubbles removed on three occasions by puncturing the side of the pouch with a needle and squeezing out the bubble. (The urge to reproduce is so strong that males go through the motions of courtship and may pick up bubbles even if no females are present.) On June seventh he was placed with a ripe, freshly caught female. On the seventeenth I cut a slit in the side of the pouch and removed a bubble and two partly formed babies. By the twentieth [3 days later] the slit was healed over, and he had another air bubble. On the 23rd I partially removed this bubble by forcing a needle through the entrance of the pouch. On the 25th [2 days later] yolk came out when the needle was inserted. On July 5th he gave birth to a large brood after which a bubble was squeezed out of the dilated opening of the pouch without the aid of a needle. The next day he sucked in another bubble while courting. Although removing bubbles does not permanently damage the fish, it is much easier to put a fence, such as a cylinder of plastic screen, around the air stone and its rising stream of bubbles” (Strawn, 1954).

Notice that Strawn performed needle aspirations on the same male several times within a short period, and even performed crude pouch surgery on the pregnant male, yet the dwarf seahorse was untroubled by these procedures, recovered fully, and eventually gave birth to large broods of young nonetheless. If the delicate dwarf male can tolerate the procedure so well, even when pregnancy complicates the picture, your Pinto should have no problem with a needle aspiration.

I know a needle aspiration sounds like an intimidating procedure but you’ll be pleasantly surprised at how easy it is in actual practice.

First of all, let me emphasize that it’s a very safe procedure. The only real risk is a slight danger of secondary infection, but if you’re using a sterilized needle that risk is virtually negligible. It’s true that the lining of the pouch is heavily vascularized — especially in pregnant males — but it is capillary rich and not fed by any major veins are arteries, so there is no significant risk of bleeding or hemorrhaging at all. Once the needle penetrates the wall of the pouch and reaches the central cavity, there is really nothing inside that it could damage. Aside from the septum — a longitudinal wall of tissue or membrane that divides the pouch into left and right hemispheres — the central cavity of the pouch is basically a void. And even if you inserted the needle far enough to pierce the central septum, no harm would be done by penetrating that membrane with a needle. The septum is a simple wall of tissue whose only purpose is to provide additional surface area on which fertilized eggs can implant. You could punch it full of holes like a sieve and it would have no detrimental effects or adverse impacts on the seahorse at all. So a needle aspiration is a simple, straightforward procedure, and even if you bungle it somehow and fail to extract the trapped fluid or gas, no harm will be done to the seahorse in the attempt. The entire procedure is virtually painless and stress free for the seahorse, although they will naturally struggle initially when being restrained.

The size of the syringe and the gauge of the hypodermic needle are really not that important. (In fact, this is one application in which larger diameter needles sometimes work better, particularly if the aspirate turns out to be fluid rather than gas.)

The procedure is accomplished while the seahorse is held under water, just as you would if burping or flushing the pouch, and you grasp the seahorse in the same manner as well.

Prepare the needle and syringe ahead of time by sterilizing the hypodermic. When you are ready, wet your hands first and hold the seahorse upright in the water with your non-dominant hand, allowing his tail to wrap your little finger or ring finger so he has a good grip and feels secure.

While the seahorse is thus restrained, use your dominant hand to insert the needle into the side of the pouch (not the front) so you can tap into the pocket of trapped fluid.

Remember, you are not performing a subcutaneous or intramuscular injection, so there is no need to use a shallow angle when penetrating the wall of the pouch. Depress the plunger all the way and then insert the hypodermic laterally, from the side of the pouch rather than the front, at a perpendicular angle to the wall of the pouch. Use a very gentle pressure to penetrate the wall of the pouch, and you should be able to feel the sudden lack of resistance as the needle passes through the wall of the marsupium into the central cavity of the pouch. In most cases, that is where the trapped gas or fluid should be.

The wall of the pouch is fairly thin, so after the needle penetrates a few millimeters you should be well within the central cavity. (The wall of the pouch thickens and enlarges in pregnant males due to the placenta-like changes that take place in the lining of the pouch, so you may have to insert the needle deeper than normal if you’re dealing with a gravid male.) If you insert the needle too far, you will encounter resistance again momentarily, indicating you have passed through the central cavity and encountered the septum; if this happens, just retract the needle slightly and you should be back in the central cavity. When you feel the needle is within the central cavity, gradually withdraw the plunger on the syringe and remove the trapped gas/fluid. Successfully aspirating the gas or fluid in this way should relieve the pressure and swelling and provide your Pinto with some immediate relief.

More importantly, it would allow you to send some of the fluid you aspirated to Dr. Belli for analysis. If the aspirate consists of watery liquid (i.e., marsupial fluid) or yellow yolk, that indicates your male is pregnant. If the fluid is discolored or purulent, that indicates an infection. If the aspirate includes gas as well as fluid, that indicates GBS is also a factor in your Pinto’s problems. Culturing this fluid and/or examining a smear on a microscope slide can determine if infection or parasites are present, and you can proceed accordingly once you get Marty’s report.

All things considered, I suggest you proceed as follows. First, perform a needle aspiration to relieve the fluid build up and recover some of the fluid to send to Dr. Belli for further analysis, if he is agreeable. While you are waiting for Marty’s report, continue the 10 day regimen of neomycin + triple sulfa, feed your Pinto Vibrance-enriched Mysis so the beta-glucan it contains can help boost his immune system, and lower the temperature of your hospital tank as much as possible.

Reducing the water temperature and cooling down the microbes will slow down their metabolism and rate of reproduction accordingly, and give the seahorse’s immune system a better chance to fight off the disease (Giwojna, Oct. 2003).

A simple way to drop the water temp in your hospital tank is to position a small fan so it blows across the surface of the water continually (Giwojna, Oct. 2003). This will lower the water temperature a few degrees via evaporative cooling (just be sure to top off the tank regularly to replace the water lost to evaporation). Leaving the light off on your hospital tank in conjunction with evaporative cooling can make a big difference and help you knock out this tail infection (Giwojna, Oct. 2003). Tropical seahorses will be fine as low as 68 F providing you drop the aquarium temperature gradually. Most likely you won’t be able to drop the temperature that far without a chiller, but just lowering the temperature a few degrees can make a big difference when fighting bacterial infections.

While you’re waiting, you might also investigate possible sources for chloramphenicol or ciprofloxacin, as alternate treatments to the antibiotics you are currently using.

You mentioned that your Pinto is beginning to act a little stressed in your hospital tank. It’s important for the hospital ward to include enough hitching posts so that the seahorse wont feel vulnerable or exposed during treatment. Aquarium safe, inert plastic plants or homemade hitching posts fashioned from polypropylene rope or twine that has been unraveled and anchored at one end are excellent for a hospital tank. No aquarium reflector is necessary. Ambient room light will suffice. (Bright lights can breakdown and inactivate certain medications and seahorses are more comfortable and feel more secure under relatively dim lighting.)

Stay on top of water quality in the hospital tank/bucket with water changes as often as needed during treatment, and redose with the medication according to directions after each water change.

Best of luck treating your Pinto. Here’s hoping he’s feeling much better soon.

Respectfully,
Pete Giwojna