It sounds like you did an excellent job of obtaining the acetazolamide tablets and treating the affected seahorse in a hospital tank for a more than sufficient period, and the Diamox is usually very effective in treating the tail bubbles or subcutaneous emphysema, so I am surprised you did not have a better outcome.
The acetazolamide (brand name Diamox) can also be administered as a series of injections, RoseJessica, as explained below in more detail:
The suggested treatment regimen for acetazolmide injections is as follows:
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.
Good luck, RoseJessica!
Here’s hoping that your prized pony is so enjoying perfect health again.
Pete Giwojna, Ocean Rider Tech Support