Clove oil sedation/anesthesia procedures?

Mr_Knightley · Oct 20, 2025

Hey all. I have had this Antennarius pictus for a year now as of the 18th. About 5 months ago, she tried to eat a feeder fish that was sitting near the surface of the water and took in a big gulp of air, and I have had her isolated in a viewing box ever since. She seems uncomfortable, swims around often, but still VERY interested in food. I've fasted her for the last two months hoping that she would pass the bubble, but to no avail.
I'm considering an extraction via hypodermic needle and need a formula for using clove oil for anesthesia. I've studied veterinary setups for fish sedation and have a plan to do it properly and have hands-on experience with animal surgery and procedures (though nothing this small).

If I can't do this properly to ensure her safety and long-term health, I will instead euthanize her with the very same clove oil. I just want to give her a chance to recover and keep enjoying life, y'know?

I house her with my other A. pictus whom I have had for two years, both in a 40g breeder. I feed them a diet of primarily fresh squid, sometimes stuffed with nutritional yeast or soaked in a vitamin supplement, and every few months give them gut-loaded live mollies. Both animals have grown in my care and display healthy weight and bodyfat distribution (at least, as far as I can tell).

Thanks in advance, have a lovely week and happy reefing!

Rocks reef · Oct 20, 2025

It is pretty normal for fish to gulp air when feeding from the surface.
Why do you think the air is still in the fish? Is it swimming weird at all? If not, I highly doubt it still has air in its digestive system. It would have been expelled or absorbed by now.
I would hold off on doing any procedures, as I stated, I highly doubt the fish still has air in its gut from 'gulping' air five months ago.

@ReefSquad
@Jay Hemdal
@vetteguy53081

vetteguy53081 · Oct 20, 2025

Mr_Knightley said:
Hey all. I have had this Antennarius pictus for a year now as of the 18th. About 5 months ago, she tried to eat a feeder fish that was sitting near the surface of the water and took in a big gulp of air, and I have had her isolated in a viewing box ever since. She seems uncomfortable, swims around often, but still VERY interested in food. I've fasted her for the last two months hoping that she would pass the bubble, but to no avail.
I'm considering an extraction via hypodermic needle and need a formula for using clove oil for anesthesia. I've studied veterinary setups for fish sedation and have a plan to do it properly and have hands-on experience with animal surgery and procedures (though nothing this small).

If I can't do this properly to ensure her safety and long-term health, I will instead euthanize her with the very same clove oil. I just want to give her a chance to recover and keep enjoying life, y'know?

I house her with my other A. pictus whom I have had for two years, both in a 40g breeder. I feed them a diet of primarily fresh squid, sometimes stuffed with nutritional yeast or soaked in a vitamin supplement, and every few months give them gut-loaded live mollies. Both animals have grown in my care and display healthy weight and bodyfat distribution (at least, as far as I can tell).

Thanks in advance, have a lovely week and happy reefing!

If air would be in the fish, it would likely be buoyant and eating is a good sign.

@Jay Hemdal

Jay Hemdal · Oct 20, 2025

Mr_Knightley said:
Hey all. I have had this Antennarius pictus for a year now as of the 18th. About 5 months ago, she tried to eat a feeder fish that was sitting near the surface of the water and took in a big gulp of air, and I have had her isolated in a viewing box ever since. She seems uncomfortable, swims around often, but still VERY interested in food. I've fasted her for the last two months hoping that she would pass the bubble, but to no avail.
I'm considering an extraction via hypodermic needle and need a formula for using clove oil for anesthesia. I've studied veterinary setups for fish sedation and have a plan to do it properly and have hands-on experience with animal surgery and procedures (though nothing this small).

If I can't do this properly to ensure her safety and long-term health, I will instead euthanize her with the very same clove oil. I just want to give her a chance to recover and keep enjoying life, y'know?

I house her with my other A. pictus whom I have had for two years, both in a 40g breeder. I feed them a diet of primarily fresh squid, sometimes stuffed with nutritional yeast or soaked in a vitamin supplement, and every few months give them gut-loaded live mollies. Both animals have grown in my care and display healthy weight and bodyfat distribution (at least, as far as I can tell).

Thanks in advance, have a lovely week and happy reefing!

Sorry,
I’m out running errands and I don’t have access to my formulary. I don’t like using Eugenol (main component of clove oil) because it needs to be dissolved in 95% ethanol. I’ve got issues with that from a toxicity standpoint.

MS-222 is a much better choice, but difficult to get in small quantities.

I’ve extracted abdominal air from fish hundreds of times, sometimes not even using anesthesia (because they aren’t analgesic anyway)….but rarely do I see a permanent cure from that.

Can you tell for sure that it is gas not liquid in the abdomen? Can you guess its location? (Stomach versus intestines)

Mr_Knightley · Oct 20, 2025

Rocks reef said:
It is pretty normal for fish to gulp air when feeding from the surface.
Why do you think the air is still in the fish? Is it swimming weird at all? If not, I highly doubt it still has air in its digestive system. It would have been expelled or absorbed by now.
I would hold off on doing any procedures, as I stated, I highly doubt the fish still has air in its gut from 'gulping' air five months ago.

@ReefSquad
@Jay Hemdal
@vetteguy53081

Most frogfish have no built in reflex for spitting out air, so they swallow it and it just hangs out in their gut unable to move along. The only exception I know of is the sargassum frogfish.

Mr_Knightley · Oct 20, 2025

Jay Hemdal said:
Sorry,
I’m out running errands and I don’t have access to my formulary. I don’t like using Eugenol (main component of clove oil) because it needs to be dissolved in 95% ethanol. I’ve got issues with that from a toxicity standpoint.

MS-222 is a much better choice, but difficult to get in small quantities.

I’ve extracted abdominal air from fish hundreds of times, sometimes not even using anesthesia (because they aren’t analgesic anyway)….but rarely do I see a permanent cure from that.

Can you tell for sure that it is gas not liquid in the abdomen? Can you guess its location? (Stomach versus intestines)

Intestinal gas is definitely a possibility as well. I had fed both fish twice in two weeks around 4 months ago (after she swallowed the air), which may have disrupted her further. The expanded region is somewhat transparent and has no apparent veins, and is closer to the front of the fish which leads me to believe it's the stomach. What makes me think its gas is that she is very unstable when swimming (like a pool toy) and usually ends up either up against the corner or wedges herself underneath something. She doesn't seem to actively float upwards, but she's at the very least close to neutral which is totally off for a frog of her size.

My father is a veterinarian, so I can check with him on what drugs he can prescribe. I've seen some literature on ketamine being used for this purpose in salmonids, which I *do* have access to through his practice.

Mr_Knightley · Oct 20, 2025

I've encircled the swollen area, you can see it's slightly transparent.

Jay Hemdal · Oct 20, 2025

Mr_Knightley said:
Intestinal gas is definitely a possibility as well. I had fed both fish twice in two weeks around 4 months ago (after she swallowed the air), which may have disrupted her further. The expanded region is somewhat transparent and has no apparent veins, and is closer to the front of the fish which leads me to believe it's the stomach. What makes me think its gas is that she is very unstable when swimming (like a pool toy) and usually ends up either up against the corner or wedges herself underneath something. She doesn't seem to actively float upwards, but she's at the very least close to neutral which is totally off for a frog of her size.

My father is a veterinarian, so I can check with him on what drugs he can prescribe. I've seen some literature on ketamine being used for this purpose in salmonids, which I *do* have access to through his practice.

Metomidate is another option to MS-222. I had researched its use in fish 20 years or so ago, but I think I can find the dose.

vetteguy53081 · Oct 20, 2025

Jay Hemdal said:
Sorry,
I’m out running errands and I don’t have access to my formulary. I don’t like using Eugenol (main component of clove oil) because it needs to be dissolved in 95% ethanol. I’ve got issues with that from a toxicity standpoint.

MS-222 is a much better choice, but difficult to get in small quantities.

I’ve extracted abdominal air from fish hundreds of times, sometimes not even using anesthesia (because they aren’t analgesic anyway)….but rarely do I see a permanent cure from that.

Can you tell for sure that it is gas not liquid in the abdomen? Can you guess its location? (Stomach versus intestines)

Typical fish will pass air in time and have buoyancy issues which I don’t see here
I tagged Jay who is at work who works with this and will respond

Mr_Knightley · Oct 24, 2025

Jay Hemdal said:
Metomidate is another option to MS-222. I had researched its use in fish 20 years or so ago, but I think I can find the dose.

Hey Jay,
I checked with our supplier and the closest they had was Etomidate.
I palpated her this afternoon and found that the bubble is, in fact, fluid. She is still positively buoyant, and has gotten progressively worse in the past few weeks, but the buildup of fluid around her abdomen is not the cause. I did attempt an unsedated extraction just moments ago. The fluid seems to be built up just under the skin, which is too flexible and durable to pierce with a needle so all I managed to do was stress her out and poke her belly.
I've got her back in an isolation box with no access to the surface. For the past 3 days after I let her free, she'd spent 50+% of her time swimming at the surface to no avail.

I am going to try to isolate her completely in her own aquarium to see if that helps at all. It's possible she's being stressed by the other fish's presence, so let's hope that helps. If these do not help her, I will consider euthanasia or taking her to a specialist exotic vet.

Thank you for your help, I'll keep the thread updated.

Jay Hemdal · Oct 25, 2025

Mr_Knightley said:
Hey Jay,
I checked with our supplier and the closest they had was Etomidate.
I palpated her this afternoon and found that the bubble is, in fact, fluid. She is still positively buoyant, and has gotten progressively worse in the past few weeks, but the buildup of fluid around her abdomen is not the cause. I did attempt an unsedated extraction just moments ago. The fluid seems to be built up just under the skin, which is too flexible and durable to pierce with a needle so all I managed to do was stress her out and poke her belly.
I've got her back in an isolation box with no access to the surface. For the past 3 days after I let her free, she'd spent 50+% of her time swimming at the surface to no avail.

I am going to try to isolate her completely in her own aquarium to see if that helps at all. It's possible she's being stressed by the other fish's presence, so let's hope that helps. If these do not help her, I will consider euthanasia or taking her to a specialist exotic vet.

Thank you for your help, I'll keep the thread updated.

I’ve heard of etomidate, but I don’t know if it is an analog to metomidate.

If you haven’t seen this, here is some text that I wrote on abdominal swelling in fish:
https://www.reef2reef.com/threads/causes-of-abdominal-swelling-in-fishes.1098720/