Pouch Evacuations in Male Seahorses
Is your seahorse floating? Gas can accumulate in a male seahorse’s pouch, causing problems with swimming, eating, and may result in death if left untreated. Fortunately, removing air in the pouch is a fairly simple procedure. A pouch evacuation is a proceedure to remove air from a seahorses pouch, and is something that many seahorse aquarists will need to do at some time or another.
At first blush, this may sound like a harrowing task, but its really very simple to do, even with the squirmiest of guys. Just remember, seahorses are smart and he’ll probably sulk and shy away for a few days. That’s okay.
Equipment you’ll need
- Shallow container with tank water
- IV catheter sleeve with needle removed (20-24 gauge depending on the size of the seahorse)
- Moral support
IV catheters, or more technically, the cannula, are available from veterinarians. Some aquarists have difficulty acquiring them easily, especially if the vet, or more likely receptionist doesn’t understand what you’re looking for. I suggest printing this article and showing them. Tell them you do not need the needle, just the cannula; frequently this helps assuage concerns about dispensing such a tool. I have also made kits that are available on Ebay for people unable to obtain them via other means.
If you cannot obtain a catheter, some alternatives are a small, soft pipette. Some people have had luck with bobby pins that have blunted tips. Back in the olden days, even toothpicks were used! However, I really recommend using the IV catheter if at all possible.
Holding The Seahorse
First, you’ll need to grasp the male firmly underwater. Some people prefer to do this in a shallow container with tank water, but once you’re proficient at it, you can even do this in the aquarium. If you do it in a separate container, make sure there is enough water to fully cover the seahorse from back to tip of snout with your hand holding him. He shouldn’t be exposed to air during the procedure.
To hold the male, position him so he is laying across the palm of your hand. I prefer having it so the male’s upper body rests between my index and middle fingers, as it aids in manipulating the pouch. You’ll want to get him to wrap his tail around your pinky or ring finger or he’ll use it to grab his head, snout, etc. to block you from getting to his pouch. He may struggle for a bit, but keep him immobilized without squeezing too tight, and he’ll calm down. Eventually. Some males take longer than others to relax.
Removing The Gas
Once the seahorse settles down, you’ll want to begin applying gentle pressure to his pouch. First try without using any tools to open the pouch. You’ll want to apply pressure from the front at the base of the pouch and work your way up. Do this in sort of a rolling fashion, keeping the area you previously applied pressure to down and working your way up. Sort of like a tube toothpaste. It’s hard to describe the exact pressure needed, but it should never require a lot. If you have to struggle to release the air, stop! At that point, you’re going to need a tool to release the trapped gas. These days, I recommend skipping right to using a catheter to tease the pouch open.
If all goes well, the bubbles will start to come out of the pouch opening. This is why I prefer doing the procedure in tank; you can tip Mr. seahorse so his pouch opening is the highest point, thus allowing the air to leave.
If it does not come out on its own, you will need to tease the pouch open. This is where it gets tricky, especially if you do it alone. But, as I can attest, it can be done on your own with patience and dedication. However, if you can find a squeamish friend to help the first few times, it might be a good idea.
Again, hold the seahorse the same way in your palm. You’ll need to gently force the air near the opening of the pouch similar to before to make the pouch opening more taut. You can do this with the thumb of your holding hand. Now, hold the catheter between your thumb and index finger of the free hand and work at pushing the sides of the opening away.
He will be holding it tight, so it may take a little while of gently working at it to get him to relax enough to let it open. You may not be able to see the opening as the pouch folds around itself here. Keep working gentle. You will know when it’s open when the stream of bubbles comes out. Hold open and with the fingers you’re putting pressure on the pouch with, keep working your way up until the air is all out.
In many males, you will have to use an iv catheter sleeve to insert completely into the pouch to release the air. Follow the above procedure to enter the pouch, and then slide in at an angle so the catheter is parallel to the body/tail. It may require gently wiggling in all areas inside the pouch to find the bubble.
I have done this on a number of occasions without any lasting problems. Earlier versions of this article indicated that I did not know if males could successfully breed after this procedure, but I’ve had no problems with males producing young after having a catheter inserted. I believe there may be a risk with repeated procedures based on the physiology of the pouch, but this is only a working theory. It seems unlikely to a problem unless the procedure is repeated frequently, but it is something to keep in mind before attempting.
Since first writing this way back in 2003, a lot has changed. A detailed article on Gas Bubble Disease in seahorses is needed, but for now, I’ll mention that one of the popular hypotheses on what causes gas bubble disease in home aquariums is dissolved organic compounds. These are difficult if not impossible for the home aquarist to test, but you can get some idea of if they are a problem based on nuisance algae growth, high nitrates, low ph, lots of detritus, and high phosphate.
Correcting these problems often corrects the underlying gas bubble disease and keeps it from reoccurring. A few strategies I’ve seen work well is improving flow rate in the aquarium; too often people hear seahorses need “slow” tanks and make the flow too low. If the aquarium does not have a protein skimmer, adding one often helps. And lastly, removing canister filters and switching to sumps frequently helps, as canister filters are often traps for organic matter.
Acetazolamide, AKA Diamox is a prescription medication frequently used to treat gas bubble disease. However, it treats the symptoms, not the cause. So frequently reoccurs. Obtaining it can be difficult; vets are often reluctant to prescribe it. I recommend referring them to the 2005 Syngnathid Husbandry Manual, as it has a recommendation written by a veterinarian.
Many folks who cannot obtain Acetazolamide via a prescription order it from overseas. InHousePharmacy. I cannot recommend this, as there is questions to the lawfulness of obtaining prescription medication this way. It’s not a scheduled drug, so there is probably little to worry about, but this is not legal advice and I am not a lawyer.
Some aquarists have noted that their seahorses really struggle when trying to do a pouch evacuation. If that is the case, I recommend sedating. I’ve never had to do this for pouch evacs, but it may be necessary. Using clove oil to sedate a seahorse is an involved procedure, but has little risk if done properly.
Video of how to do a pouch evacuation. Thanks to Momo Yang for putting it together!
Last updated 05/07/2015: Updated information on the procedure, changes to the recommendations on what tools to use, brief discussion on the possible cause, additional treatment options and mention of sedation.
Update 8/27/2014 Pouch Evacuation video included in article.