When to euthanize rosy tetras?

[Phish111]

I have had 4 Rosy Tetras battling Columnaris for a cpl months now in hospital tank. Started w Meth Blue baths and aquarium salt added to tank. Disease progressed, so treated with Kanaplex and Furan2. I see improvement as far as the cottonmouth but 2 of their gills appear necrotic and I'm afraid the damage is irreparable at this point. Including some pics. Just trying to figure out if euthanizing is the kinder option at this point.

 

[Phish111]

Original Rosy Tetras w columnaris or fungal? | 471435 | Freshwater Fish Disease and Fish Health

 

[BigBeardDaHuZi]

IMO If an animal can be saved, save them. But sometimes, when there is no hope and only suffering, we have a duty to end their pain quickly and gently.

 

[Phish111]

Agreed, I've tried so hard to help these fish. Everytime the deed crosses my mind, they'll actually eat more than what they have been. Or come out of hiding and make a few laps. The gills really worry me tho, and I most def can't stand the thought of them suffering. Ugh.