No, it would not be irresponsible of you to do whatever you think is best, since you are in the best position to judge your seahorses’ condition and assess your ability to administer treatments and provide them with care. I will certainly trust your judgment on whatever course of action you decide to pursue.
Yes, I know a needle aspiration is a tricky procedure under the best of circumstances, and much more so if you must perform its solo, without a helping hand to help you retract the plunger when all is ready. There’s really not much point in continuing your efforts to aspirate his pouch if Dr. Belli is unwilling or unable to do a laboratory analysis of the fluid you aspirated at this time, so you certainly may retire your needle and syringe and leave your Pinto be in peace if you feel that’s best.
The redness and inflammation of his tail, and the erosion on the tail of his tankmate, are symptoms of bacterial infections, which are unlikely to improve without treatment, so be sure to keep the affected seahorses isolated from the rest of your herd to present the problem from spreading.
If you want to leave them in peace and let nature take its course, lest your efforts to treat them only stress them out all the more and do more harm than good, that’s fine as long as you keep them isolated and don’t jeopardize the health of the rest of your seahorses. Keep feeding them Vibrance-enriched Mysis so they are ingesting beta-glucan to boost their immune systems, and lower the temperature on your hospital tank or treatment tank as much as possible. As you know, if you can reduce the water temperature sufficiently, bacterial infections will sometimes resolve themselves without any further treatment.
When the medicine arrives, you might also want to consider administering the ciprofloxacin orally to your Pinto and his tankmate. This can be accomplished easily by preparing a solution from the ciprofloxacin capsules or tablets and injecting it into feeder shrimp or even frozen Mysis, which can then be fed to the affected seahorses as usual. Antibiotics are often more effective when ingested, and this is a very stress-free way of administering the medication since you don’t have to handle the seahorses or otherwise cause them any distress. Let me know if you would like to try bioencapsulating the ciprofloxacin this way, and that will be happy to provide you with complete instructions on how to proceed.
In the meantime, if you like, I would be happy to contact Dr. Martin Belli on your behalf to see if I can persuade him to do a laboratory analysis of any fluid you may aspirate from his pouch in the future (1/4 cc of material would be ample for such an analysis). If Marty agrees, I could also provide you with instructions explaining how to sedate the Pinto using clove oil for this procedure, which is quite safe and should make it easier for you to perform the needle aspiration on your own.
Best of luck with your Pinto in his tankmate, Helen!