Aquariums: Older golden dojo loach showing severe weight loss and buoyancy issues — seeking care advice (photo included)

Hi everyone, I’m looking for advice from people experienced with dojo loaches, especially older ones.

My boyfriend has a golden dojo loach I named Henry that he’s had since it was a baby — so he’s pretty old at this point. Unfortunately, over time he’s slowly stopped keeping up with proper aquarium care, and I’ve ended up maintaining multiple tanks in the house (my 20g shrimp tank, a 150g cichlid tank, and Henry’s 50g).

I checked on him today and he’s clearly not doing well. Photo attached.

(Mods: please let me know if NSFW tagging is preferred here — happy to adjust.)

What I’m seeing:

• Sunken abdomen / visible wasting

• Abnormal body curvature, with the midsection raised, possibly indicating buoyancy or swim bladder issues

• Pale coloration and overall poor body condition

What I don’t see (yet):

• His abdomen does not appear fully collapsed or fused, which I’ve seen described in end-stage starvation cases — but I’m unsure how this presents specifically in dojo loaches.

Tank info:

• 50-gallon aquarium

• A few cherry shrimp as tankmates

• Water quality is currently being maintained; past feeding consistency was clearly insufficient

Important note/request:

Please be kind and constructive. I’m not posting this to antagonize, ridicule, or debate tank conditions — I’m already aware the situation isn’t ideal and I’m disappointed it reached this point. I’m here now trying to help, and I’m specifically looking for guidance, experience-based advice, and possible remedies. My focus is on helping the fish, not hyper-fixating on what someone should have done in the past.

I personally keep kuhli loaches, not dojo loaches, so I’m unsure how much recovery potential there is here, especially given his age.

My questions:

• Does this appear to be recoverable starvation, or is this more consistent with end-stage wasting?

• Can malnutrition cause secondary swim bladder or buoyancy issues in dojo loaches?

• If there is a chance of recovery, what is the safest way to re-feed without causing additional harm?

• At what point should I prioritize comfort and quality of life over intervention?

I want to do right by Henry and make informed decisions based on experience rather than guesses. Any constructive insight would be greatly appreciated.

Thank you.