13/01/2026
This isn't a rescue, but He's worth talking about.
This is lumpy, I diagnosed him with cancer sometime last year, and upon further research. It's herpes. Carp pox specifically.
Good news, they don't effect his quality of life, they are treatable (though I will not be treating them) and he's about as happy as a Koi can be, which roughly translates to: he ate today, there's a female in the tank, and he pooped when I left. I love Koi/goldfish, such simple creatures.
The only real treatment is surgical, which, surprisingly, I believe that I could perform, but it's largely unnecessary, and really only reserved for show fish that get it. Because when you spend $6,000 on a fish, and are planning to show it, it needs to not have these growths.
I've seen a few people do it, it's not unheard of.
Ironically, I will never preform a pox removal surgery, because this variant is harmless, can't transmit to humans, and is just... There. And if someone asked me to do it on a show fish, I'd laugh and leave. No way I'm getting involved in that mess.
But fish surgery is probably one of my favorite things to talk about, because it's weird.
First, you need a fish suffering from some form of injury.
Let's say we're closing up a ripped belly that opened the cavity and exposed organs to water.
Place the fish in a hospital tank, use water from the aquarium and then slowly acclimate him to a mix of about 50/50 clean treated water and aquarium water over the course of 4 hours.
Prepare a 5 gallon bucket with the same 50/50 mix.
Gather the following things. A small bowl, clove oil from the essential oils section*, or a toothache kit with the little brown bottle. The bottle can dose a 20 gallon tank. A water fountain pump, the smallest one they sell on Amazon. it uses a USB to power it. A length of soft rubber tubing, a bucket, a scalpel or razor blade, hemostats, tweezers, veteranary glue, Antibiotics, you are going to be looking for broad spectrum, gram stain positive and negative, a Rubbermaid container, wide and kinda shallow, a clean and fresh plastic cutting board, and really good light. Like so good it washes out your phone when you look at it, use two sources. Make sure your screen is far enough away so you don't have it washed out. Finally, you'll need a paper clip, one of the black clamp type. Size it so it matches the fish, but not so big that it can slip off of their gills.
Before I begin, this is always a last resort last resort, fish surgery does not exist outside of a few cases of hobbiests and aquariums, and is absolutely not advisable unless you are completely out of options. Do not do this without contacting an expert. I will only be able to help if you wave liability and acknowledge that the fish is likely going to die. I don't know how to say it other than THIS IS A BAD IDEA DO NOT OPERATE ON FISH.
1.Look over the fish again. How big is the animal? Notice every injury, look over the open wound, does it actually extend into the body cavity? Is it showing any signs of deeper trauma? Can you see anything coming out of the rip, what color is it? How is the animal behaving? Is it listing, showing signs of succumbing to the injury? Unable to right itself? If any of these are present, or the discharge from the wound anything other than blood, you're done. Skip to the end for euthanasia instructions.
2. Call a vet. Call a few. If there is literally nobody else available, you may now proceed.
2.1To transport the animal to a clinic, you will need to put it in a 5 gallon bucket, preferably with a lid. The bucket you prepared before will work
2.2 Add the bottle of eugenol to the hospital tank by pouring it into your bowl and diluting it with tap water, it's okay if it's not declorinared. if you're using a bottle of clove oil, you will want to use a teaspoon per 20 gallons. Do not add eugenol to your main tank.
2.3 wait for the fish to stop all movement, and then gently pick them up, and move them to the bucket clean the hospital tank and refill it with the same 50/50 mix of tank and pure water.
3. You will now begin prepping your surgical field, wash your hands and glove up. The cutting board goes over top of the shallow Rubbermaid container. Add your eugenol/clove oil into the hospital tank. You will now dump water from the hospital tank into the surgery tank, until the pump is fully covered. get your hemostats and scalpel, and set your phone timer for 20 minutes.
4. Follow steps 2.1 and 2.2, transporting the fish to the cutting board instead of to the bucket. At no point will eugenol come into contact with the bucket. The timer starts now. When it goes off you will have five minutes to finish.
5. Clip the hose from the pump to the fish's lip, and run water over his gills from the surgical tank. The fish has been successfully anestitized and is now ready
6. Second inspection. Look at the wound. Note discharge, bleeding, anything that stands out. If you see loops of intestine, gently look them over without clamping them or moving them. Do you see any rips or tears. If yes, skip to the end for euthanasia instructions.
7. Gently push any exposed intestine back into the cavity using your pinky finger. Only allow that finger to enter enough to push intestines back in.
8. Use the scalpel and hemostats to remove the scales from around the wound, then slice around the edges of the wound until you've removed the tissue down to bloody fresh tissue. Drain all water from the cavity and dry the site for closure.
9. Press the outside edges of skin together, then go over it with glue. Then add two stitches in the center of the wound to add structural support to the area.
10. Once you are done, transport the animal to the bucket, and begin cleaning the hospital tank and preparing it for longer term treatment. Get soap and scrub every inch of the aquarium as much as you can, take your time, it's okay for the fish to be in the bucket for quite a while. Get it back to the 50/50 but leave enough room to gently dump the bucket into the tank with the fish. Add a high dose of antibiotics. Please note that none of these instructions involve a sterile field. Everything is full of bacteria, and while we can sterilize the water we must also realize that the water in the hospital tank is full of bacteria, and basically everything else. So sterility is basically a joke.
And you're done. Again, it might go belly up in the bucket, nobody involved has any experience with this, it might get an infection, there are ten thousand things that can go wrong from here. Dose your antibiotics and change the water daily.
After Three days, you may follow steps 2.1 and 2.2 to transfer the fish back to the main tank.
For euthanasia:
If the animal is in the hospital tank, follow steps 2.1. cover the tank with a towel and leave. Come back when you feel like it. You did the best you could, and the fact that you even considered this is admirable. Give it at least 30 minutes to work, but realistically you can leave it overnight.
If the animal is already on the surgical table, gently remove them, place them back in the hospital tank, towel, leave.
Fish are not like dogs or cats, they're prey animals and do not have the same social needs as a dog or cat. They are also specifically anxious about movements above them, which is where we tend to be in this setting. They don't need you, you will scare them. Give them darkness and peace.
I'm more writing the latter half of this post so I can say "hey, I'm not butchering fish, I have a procedure." Is it good? No. Do I think it's really cool that it's possible? Absolutely. Will I ever do it? God I hope not.
*I found a use for them!
