Pouch Evacuations in Male Seahorses

By: | Date: 04/11/2003 | 12 Comments |
Upside-down seahorse

Uh Oh. A seahorse floating Upside-down is a sign of gas in the pouch.

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.

How to hold male seahorse for evacuation

How to hold male seahorse for evacuation

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.

Do not rub or massage the pouch! One common mistake is the use of rubbing as the term “pouch massage” is often used to describe thus procedure. The pouch is soft skin so intensive rubbing can lead to skin damage and infection. Instead, you want to apply pressure in a more direct pushing fashion. You may also need to gently squeeze the sides of the pouch to direct the air towards the opening, using the free hand to squeeze while using you holding hands thumb to push.

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.

Demonstration with catheter.

Demonstration with catheter.


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.

Update 2015

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.

I now have catheter kits available for aquarists. You can purchase through this ebay listing.

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.

12 Responses to “Pouch Evacuations in Male Seahorses”

  1. MelMegan Says:

    Scary, what if you can’t controlled it? Is this can be fatal to them? What are the specific pipes for?

  2. Elizabeth Schumacher Says:


    I have a sick seahorse and I don’t know what to do for him. I can’t find a vet, even did the on line and no one answered me, he had gas bubbles in his pouch a few months ago and recovered from just massage them out. Last night I found himon the bottom of my tank and was breathing, but one of his eyes have a gray cast to them. I had ordered a pouch kit and and flushed his pouch witht the antib otic that it came with from ocean rider. Is there anything I can do for him?

    Liz Schumacher

  3. TamiW Says:

    It sounds a lot like a bacteria infection. I would recommend placing in a hospital tank, lowering the temperature down to 68 degrees over the course of a day, and treat with a regiment of antibiotics. Temperature control is going to be the biggest thing you can do to help now, as the bacteria spreads slower at lower temperatures.

  4. Elizabeth Schumacher Says:

    I do not have a hospital tank, I have an old 10gallon but no extra sand. At the moment can’t reach him he when between to immovable rocks. I noticed that one eye is normal and one eye is while and cloudy, he seems to be sensitive to light. Anything else I can do for him?

    I took a picture this morning, but I don’t know how to send it to you.


  5. TamiW Says:

    You can get an account and post pictures to the forum here: http://www.fusedjaw.com/forums/viewforum.php?f=8

    A hospital tank shouldn’t have sand. It should be bare bottom with artificial hitching posts, a filter, and possibly a heater, though if you’re trying to get the temp to 68 you probably don’t need one. Since you don’t have one set up already, you’re going to need to do daily water changes and keep an eye on ammonia. The only way you can treat with antibiotics without doing injections is in a hospital tank.

    You could try lowering the temperature in the main tank to 68 and see if it passes, but if you have any cold sensitive inhabitants, this could stress or kill them. I also haven’t had a lot of luck with cool temperatures alone once symptoms start showing; generally a course of antibiotics is necessary.

    As for finding a vet, back to your original comment, I’ve found that getting to talk to a reptile vet you have the best shot. its not the same type of animal, but in my experience, they’re more willing to try to help. However, you need to get ahold of the vet themselves, often times the receptionists are no help at all.

  6. Elizabeth Schumacher Says:


    With the help of a friend we set up a 10gallon hospital tank, was able to relocate the seahorse and floated him in the hospital tank while he was floating he was alert and swimming around. once we put him in the hospital tank he actually was swimming good and went to the shell to see if any food. I put a few mysis shrimp but he would not eat. He’s back to lying on the bottom, seems to be sensitive to light so I put brown paer ion the side of the tank to keep it dark. Were you able to see the picture?

    I did the on line vet but she pass, said she had no advice. Hope this works, but i do not see any fungus or spots, only his pouch is very narrow, not full like normal.


  7. Elizabeth Schumacher Says:


    Well it’s been 3 days, and he’s still alive but not eating. Tried to hand feen him; he sucks in the food and than spits it out? Why wouls he spit the food out?

    How can send you a picture? His eyes are cloudy like he has caracts? Doing water changes and adding the Methylene Blue and today added Maracn-Oxy.

    Any other suggestions? I can’t locate vet in my area, called the Balitomore Aquarium but no one could help me. I even called the manufacture of Kordon and spoke with a doctor, but he said to add the Maracyn-Oxy or Maracyn two, but my pet store did not have the Maracyn two.

    Thanks for your suggestions

  8. ryan Says:

    wow that’s incredible! is it really necessary to do this procedure? what happens to he male seahorse if you won’t try and take out the air from the pouch?

  9. Aquagrrl Says:

    It can necessary. If the air builds up to much and the male doesn’t release it on his own, it can cause him to float and lose the ability to control how he swims. This is distressing, but also keeps them from eating because they can’t chase down food.

  10. Will Says:

    What are the signs of pouch emphysema? Can it occur while pregnant? How can you differentiate pouch emphysema from a pregnancy?

  11. Tami Says:

    The most obvious sign will be floating and an inability to swim upright. Some males lean to the side if the bubble is balanced in one direction or another. Another sign is a male that doesn’t want to move, this may be because hitching is the only way he keeps from floating upside down. However, pregnant males do tend to be less active, so it’s certainly not definitive.

    It can occur during pregnancy as well. I’ve given many pouch evacuations to pregnant males. Usually the brood is lost or a partial loss, but it is more important to treat the male.

  12. Elaine Says:

    Such an informative read Tami.

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