Persistent problem with positive buoyancy

Dear KC:

You have done an outstanding job of managing the situation thus far, KC, but I do have a couple of suggestions to offer.

I think you are correct in that the unfavorable conditions in the small hospital tank (i.e., a lack of water depth and therefore hydrostatic pressure coupled with stress due to the difficulty in maintaining optimum water conditions in an aquarium without a well-established biofilter) are what triggered the problems with gas bubble syndrome (GBS). And you did very well to acquire the acetazolamide (brand name Diamox), which is the most effective treatment option for most forms of gas bubble syndrome.

As you know, the acetazolamide can be administered in a number of different ways, and the best method of administration will vary depending on the form of gas bubble syndrome you are treating. For example, chronic pouch emphysema is best treated by administering a Diamox pouch flush, after first evacuating any air bubbles from the seahorse’s marsupium. Likewise, subcutaneous emphysema (commonly known as tail bubbles) can be successfully treated by a prolonged immersion in a series of Diamox baths or by administering the Diamox orally via feeder shrimp that have been injected with a solution of the medication. When you are dealing with positive buoyancy associated with an episode of gas bubble syndrome that is suspected to be the result of internal gas bubble syndrome or hyperinflation of the swimbladder, intradermal or intramuscular injections of acetazolamide and ceftazidime are by far the best approach, and that is what I would recommend for Jasper at this point, particularly if you have access to and exotics’ vet or aquatic vet who treats marine seahorses.

In that case, KC, the suggested treatment regimen for acetazolmide injections is as follows:

Acetazolamide Injections

Inject acetazolamide at a dosage of 2-3 mg/kg intradermally or intramuscularly every five to seven days for up to three treatments. For best results, add ceftazidime (Fortaz) injections to the treatment regimen at a dosage of 22 mg/kg intramuscularly every 5-7 days, again for up to three treatments. (Ceftazidime is an antibiotic). If these drugs prove hard to find, the acetazolamide injections alone often appear to be nearly as effective as the combination treatment, but the combination of acetazolamide and ceftazidime is especially effective.

In order to determine the proper dosage for the intramuscular injections, you need to be able to weigh the seahorses accurately, and you must obtain the injectable form of the medications (it is not feasible to prepare a solution of the medication using Diamox tablets).

Due to their bony exoskeleton, injections are particularly challenging with seahorses. Seahorses store their limited fat reserves primarily in their tail, which is the most muscular part of their body. The meaty part at the base of the tail is best suited for IM injections. If you attempt the intramuscular injections, I would suggest targeting the base of the tail just beneath the pouch using a ventral approach with a shallow angle of attack. The needle should be directed between the scutes/plate margins for ease of penetration through the skin. The external area can be rinsed with sterile saline or a drop of a triple antibiotic ophthalmic solution applied prior to needle penetration.

Administering acetazolamide in the form of intramuscular injections is impractical for most home hobbyists, of course, and the medication is also effective when administered using other methods for forms of the condition other than internal gas bubble syndrome, as explained below:

Once you have obtained the acetazolamide (brand name Diamox), it is very effective in treating subcutaneous emphysema or tail bubbles when it is either administered orally by injecting a solution made from Diamox (the tablet form of acetazolamide) into feeder shrimp or when it is administered as a 7-10 day series of baths (and it can also be easily administered as a pouch wash, but that is more appropriate when treating pouch emphysema than tail bubbles), as explained below:

Acetazolamide Baths (prolonged immersion)

The recommended dosage is 250 mg of acetazolamide per 10 gallons with a 100% water change daily, after which the treatment tank is retreated with the acetazolamide at the dosage indicated above (Dr. Martin Belli, pers. com.). Continue these daily treatments and water changes for up to 7-10 days for best results (Dr. Martin Belli, pers. com.).

The acetazolamide baths should be administered in a hospital ward or quarantine tank. Acetazolamide does not appear to adversely affect biofiltration or invertebrates, but it should not be used in the main tank because it could be harmful to inhibit the enzymatic activity of healthy seahorses.

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 hospital tank, minus the residue, of course, at the recommended dosage:

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 at the same dosage 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 up to 7-10 treatments have been given. About 24 hours after the 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.

One of the side effects 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.

The seahorse usually show improvement of the tail bubbles within three days. Dr. Martin Belli reports they nearly 100% success rate treating subcutaneous emphysema when this treatment regimen is followed for 7-10 days, and most cases clear up in less than a week. For best results, the Diamox should be used in conjunction with a good broad-spectrum antibiotic to help prevent secondary infections. A good aminoglycoside antibiotic such as kanamycin or neomycin would work well for this.

If you prefer, you can also administer the acetazolamide orally, providing your stallion is still eating, which will allow you to treat the affected seahorse in the main tank amidst familiar surroundings and in the company of its tankmates where it is the most comfortable. You get the acetazolamide into the food by preparing a solution of the medication, as described below, and then injecting it into live feeder shrimp or even the large Piscine Energetics frozen Mysis relicta. The medication is deactivated fairly quickly once you prepare the solution for injecting, so you must prepare a new acetazolamide solution each day during the treatment period. Here’s how to proceed:

Administering Acetazolamide Orally

I have found that acetazolamide 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 acetazolamide 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."

Hawaiian volcano shrimp or red feeder shrimp (Halocaridina rubra) 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 reports 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. Their 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.

Administering the Diamox orally in this way is the least stressful way to medicate the seahorse, so you may want to consider trying that first before you resort to the Diamox baths or pouch flushes.

Finally, KC, the acetazolamide can also be administered in the form of pouch flushes, which is the most effective method of treatment when dealing with male seahorses that have developed chronic pouch emphysema:

Diamox Pouch Flush Instructions

ACETAZOLAMIDE (pouch flush) Dosage and Preparation Instructions
Active Ingredient: Acetazolamide
Indication: persistent and recurring pouch emphysema
Brand Name: Diamox
Dose at 0.5mL of a 62.5mg/cup solution
Supplies: narrow gauge irrigating cannula or narrow gauge IV catheter sleeve, 0.5 or 1mL syringe without needle

• Mix 62.5mg of Diamox (1/4 of a 250mg tablet) with 1 cup (approx. 237mL) of marine water with specific gravity, pH, and temperture matching that of the aquarium.
• Let the mixture settle.
• Fill the syringe with about 0.5mL of the solution, avoiding the residue that has settled to the bottom of the container.
• Hold the seahorse according to the procedure for pouch evacuations. Insert the catheter sleeve slowly and gently a small way into the pouch opening.
• Inject the solution slowly into the seahorse’s pouch. Leave the solution in the pouch.

Okay, KC, that’s the rundown on the different methods of administering acetazolamide and the proper dosages for each of the procedures.

At this point in Jasper’s journey, I think your best bet is to administer acetazolamide as a series of injections in conjunction with injections of ceftazidime with the help of the exotics’ vet, as we discussed previously.

Best wishes with all your fishes, KC!

Respectfully,
Pete Giwojna, Ocean Rider Tech Support

Dear KC:

Okay, I would certainly have the exotics’ vet go ahead and administer the ceftazidime injection regardless of whether or not he has access to the injectable form of acetazolamide as well.

If Jasper’s positive buoyancy problems are due to a hyperinflated swimbladder, there are two relatively simple techniques that you may consider to provide him with some quick relief. The first of these is to perform a needle aspiration to manually remove some of the excess gas from the swimbladder, but this is an invasive procedure and if the vet has never done such a procedure before, you may want to consider the second alternative instead, KC. Pressurizing the seahorse at depth can be equally effective if you have a tank available that is sufficiently deep. The increased hydrostatic pressure at depth will compress the swimbladder and cause it to shrink accordingly, and the change in water pressure will also trigger the heavily vascularized oval in the swimbladder to begin resorbing excess gas.

The effectiveness of the latter technique is largely dependent upon the water depth you can achieve. Professional aquarists who use this method for treating gas bubble syndrome will typically immerse the affected seahorse at depths of anywhere from 10 feet to 35 feet for one or two days in order to achieve the desired results. In general, the greater the water depth at which the seahorse can be immersed, the more effective the pressurization process will be and the shorter the duration of time it needs to be maintained.

Very little research has been done to determine how deep a seahorse needs to be pressurized and for what duration in order to achieve the best results, but anecdotal reports suggest that even as little as 36-40 inches of water depth can be helpful in some cases. The affected seahorse is usually confined within a small flow-through enclosure which can be lowered to the bottom of a tall tank in order for the increased water pressure to naturally shrink and deflate the swimbladder.

If you do not have a sufficiently deep tank or container in order to try pressurizing the seahorse, then you may certainly consider having the aquatic vet perform a needle aspiration to manually remove the excess gas instead, KC.

Manually deflating the swimbladder is accomplished much like a needle aspiration, except the needle is inserted into the gas bladder rather than the pouch. This is how Dr. Marty Greenwell from the shed aquarium describes this procedure in the 2005 Seahorse Husbandry Manual:

"If a hyperinflated swimbladder is suspected, a bright light can be directed from behind the animal to visualize the location and borders of the distended organ. This is useful when attempting to deflate the bladder. The needle should be directed between the scute/plate margins for ease of penetration through the skin. The external area can be rinsed with sterile saline or a drop of triple antibiotic up all my appointments can be applied prior to penetration."

The seahorse’s swimbladder is a large, single-chambered sac that begins in the band of its neck and extends 1/3 of the length of its body cavity along the dorsal surface. It’s a large organ so if you can visualize it clearly using a bright light from behind the seahorse (just like candling an egg), and releasing some of the gas to partially deflate the swimbladder is fairly straightforward and uncomplicated.

If you contact me off list by e-mail, KC, I will send you some good illustrations of the internal anatomy of the seahorse which show the location of the swimbladder or gas bladder, so that you can print them out and share them with the exotics’ veterinarian so he will have a better idea of how to proceed. You can reach him at the following e-mail address any time:

[email protected]

Best of luck restoring Jasper to neutral buoyancy again, KC.

Respectfully,
Pete Giwojna, Ocean Rider Tech Support