By the way... Although at some time, we may have to medicate our "charges", it really should be the last resort. I've only once used Neosporin on the tail of one of my girls when she was nipped by a crab. I've had my ponies for two plus years now and haven't used any other meds at all. Yes, seahorses bring with them a TON of possible issues, but personally, I feel that they are tougher than what we give them credit for.
In one instance, I accidentally lodged one of the females in a nook of Tonga Branch Live Rock. I was using the turkey baster to blow detritus off of the rockwork and didn't even notice her there. I sent a strong stream at her and she ended up backed in, head stuck, right at the gills. I waited for some time to see if she could get herself out and she could not. She started to become pale and her respiration was off the wall. I HAD to do something. I pushed her back through and released her, but damaged both pectoral fins in the process. She was NOT stoked. I had to target feed her for weeks until her tattered fins grew back. All that time, I didn't medicate her at all.
The ONLY med that I use on a regular basis is Formalin and I use that only in the fry tanks.
In the case of internal gas bubble disease, I would first recommend using a capillary tube to try and release the gasses from the pouch. Many people have reported that this is easier and less invasive as you would think.
Prevention is key. Ensuring that you don't have a lot of micro bubbles in your system is one such method. If you use a skimmer and it creates these bubbles when you feed oily foods, either a) turn off the skimmer for some time during and after feeding or b) re-engineer your system to include bubble traps, baffles and other means of eliminating the bubbles.
I'd also advise that you do keep seahorses in tallish tanks. Not only does it give them the room to perform courtship rituals, but it creates an environment whereby the ponies have a more adequate environment to avoid these bubble issues. (this is just my thoughts and not "scientific" at all).
Simply put, bubbles float and in a low flow tank, should rise and dissipate quickly, leaving the bottom most part of the tank free of these bubbles. Unless your ponies hang at the top of your system (most do not) then they will not be subjected to the micro bubbles.
Second point, a taller tank may create differing "pressure" in the various levels of the water column. The water pressure in a tall tank is somewhat more prevalent in the lower section of the tank and less an influence in the upper water column. The higher pressure in the lower sections can act as a sort of decompression zone and help the pony eliminate gasses or avoid them all together.
Finally, please keep in mind that ANY LIVING CREATURE can build up immunities towards medications. If we all use meds as the first option, there may soon come a day when those same medications do not work for us at all.