Goldfish with tail rot (or injury)

[Jim Sinclair]

This is one of my baby goldfish, hatched July 21st, now four months old. This is one of the larger ones that has been living in the 440 gallon basement pond with my 9 adult fish and the biggest of the baby fish that I deemed large enough to be out of danger of being eaten. I was just doing a water change when I saw this one floating on top of the water. It is alive. (Video showing aliveness and swimming at

.) The tail is mostly gone, but I don't see any damage to the other fins, or any spots or marks on the body.

The fish is now isolated in a hospital tank. I have on hand:

Plain salt (NaCl, no iodine, anti-caking agents, or any other additives)

Epsom salt (pure magnesium sulfate, no additives)

API E.M. erythromycin

Paraguard

And it seems to me I remember seeing what's left of the bottle of Kanaplex I got several years ago for a fish with extensive fin damage and sepsis (it didn't help him), but I can't find it right now.

And there's a local aquarium shop that's closing in a few minutes but will re-open tomorrow afternoon.

What do you recommend?

 

[Jeremy180]

I Recommend very frequent water changes of 50% or more, preferably at least twice weekly, and more would not hurt if you have the time.

I do not have much experience with medications, so beyond that, I don't have much to contribute, but Colin_T has quite a bit of knowledge in this area.

 

[Colin_T]

How long has the fish's tail been like that?

Was the tail fine one day and missing the next?
If yes, the other fish probably ate its tail.

Bacterial, fungal and protozoan infections take more than 24 hours to dissolve a tail to that degree.

The tail does not look infected. There is no red in it (what's left of it), or around the edges so it doesn't appear to be bacterial.

The fish appears to be free of protozoan infections on the body and remaining fins so that is unlikely to be the cause. Protozoan infections show up as cream, white or grey patches on the body and sometimes fins, and the infected fish tend to rub on objects.

There is no fungus on the tail.

-----------------------
Kanaplex and Erythromycin are both strong anti-biotics that should not be used unless there is a known bacterial infection that has not responded to conventional fish medications.

Anti-biotics will kill filter bacteria and improper use or misuse can lead to drug resistant bacteria that can kill people, animals, birds and fish.

-----------------------
ParaGuard contains aldehydes and Malachite Green and is useful to treat protozoan ifnections. However, this does not appear to be a protozoan infection so should not be used.

Malachite Green is carcinogenic and you should avoid getting it on your skin. And wash hands and arms with soapy water after using any medication or working in the tank.

-----------------------
Epsom Salts (magnesium sulphate) is only useful to increase the GH a bit and help with constipation.

-----------------------
Sodium Chloride (salt) is fine to help reduce stress and treat minor bacterial, fungal and protozoan infections in fish. If you want to use it you can add some to make sure the tail doesn't get infected.

You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 2 heaped tablespoons per 20 litres and increase it after 48 hours if there is no improvement so there is a total of 4 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate will affect some plants. The lower dose rate will not affect plants.

After you use salt and the fish have recovered, you do a 10% water change each day for a week. Then do a 20% water change each day for a week. Then you can do bigger water changes after that.

-----------------------
Check the water quality for ammonia, nitrite, nitrate & pH.

Do a 75% water change and gravel clean the substrate. Wipe the inside of the glass down and clean the filter if it hasn't been done in the last 2 weeks.

Add salt and monitor the fish over the next 2 weeks.

As long as the tail doesn't get infected it should heal up without any problems and grow back over the next month or so.

Keep the fish away from other fish for a couple of weeks to let it recover in piece.

-----------------------
If you turn your phone on its side so it is horizontal, the video will fill up the entire screen rather than only using the middle section for the footage

 

[Jim Sinclair]

I have no idea how long the tail has been like that. I first noticed it this evening while doing a water change in the pond. If I had noticed it earlier, I would have separated the fish earlier. As you may recall, I have almost 300 baby fish, divided between four smaller tanks plus the largest ones in the big pond with the adult fish. I am not able to monitor every fish every day to be able to tell when this started. If this fish had not been floating at the top looking dead, I would not even have noticed it this evening, with the size of the pond and the number of little fish in it.

It's now in a hospital tank with a bubbler (because all my filters are already in use; will see what I can do about that tomorrow) and some salt. It's swimming around and looking a little stronger and more lively, whether from the salt or just from the warmer temperature upstairs compared to the basement, I can't say.

I don't know how the phone decided whether it was horizontal or vertical while I was trying to keep it aimed at the frantically swimming fish. *I* sure couldn't tell what orientation it was in! I was just trying to keep the fish in the picture.

How long has the fish's tail been like that?

Was the tail fine one day and missing the next?
If yes, the other fish probably ate its tail.

Bacterial, fungal and protozoan infections take more than 24 hours to dissolve a tail to that degree.

The tail does not look infected. There is no red in it (what's left of it), or around the edges so it doesn't appear to be bacterial.

The fish appears to be free of protozoan infections on the body and remaining fins so that is unlikely to be the cause. Protozoan infections show up as cream, white or grey patches on the body and sometimes fins, and the infected fish tend to rub on objects.

There is no fungus on the tail.

-----------------------
Kanaplex and Erythromycin are both strong anti-biotics that should not be used unless there is a known bacterial infection that has not responded to conventional fish medications.

Anti-biotics will kill filter bacteria and improper use or misuse can lead to drug resistant bacteria that can kill people, animals, birds and fish.

-----------------------
ParaGuard contains aldehydes and Malachite Green and is useful to treat protozoan ifnections. However, this does not appear to be a protozoan infection so should not be used.

Malachite Green is carcinogenic and you should avoid getting it on your skin. And wash hands and arms with soapy water after using any medication or working in the tank.

-----------------------
Epsom Salts (magnesium sulphate) is only useful to increase the GH a bit and help with constipation.

-----------------------
Sodium Chloride (salt) is fine to help reduce stress and treat minor bacterial, fungal and protozoan infections in fish. If you want to use it you can add some to make sure the tail doesn't get infected.

You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 2 heaped tablespoons per 20 litres and increase it after 48 hours if there is no improvement so there is a total of 4 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate will affect some plants. The lower dose rate will not affect plants.

After you use salt and the fish have recovered, you do a 10% water change each day for a week. Then do a 20% water change each day for a week. Then you can do bigger water changes after that.

-----------------------
Check the water quality for ammonia, nitrite, nitrate & pH.

Do a 75% water change and gravel clean the substrate. Wipe the inside of the glass down and clean the filter if it hasn't been done in the last 2 weeks.

Add salt and monitor the fish over the next 2 weeks.

As long as the tail doesn't get infected it should heal up without any problems and grow back over the next month or so.

Keep the fish away from other fish for a couple of weeks to let it recover in piece.

-----------------------
If you turn your phone on its side so it is horizontal, the video will fill up the entire screen rather than only using the middle section for the footage

 

[NickAu]

You can also use Kosher salt.

 

[FishGuest5123]

Hi, Jim. I think a larger fish bit it as the fins show no damage. I would keep the water clean by doing daily water changes and use aquarium salt. Watch for infection and if it should occur, then you’ll need an antibiotic. I would throw the Kanamycin out if it is several years old as it has lost its potency. Good luck and keep us posted. Found any homes for the babies yet?

 

[Colin_T]

I would throw the Kanamycin out if it is several years old as it has lost its potency.

If you have old anti-biotics to get rid of, take them to a chemist and ask them to dispose of it properly.

If the tail does get red, inflamed or white and fluffy, post another picture asap and we can advise you on what to use.

 

[Cichlid4life]

This is one of my baby goldfish, hatched July 21st, now four months old. This is one of the larger ones that has been living in the 440 gallon basement pond with my 9 adult fish and the biggest of the baby fish that I deemed large enough to be out of danger of being eaten. I was just doing a water change when I saw this one floating on top of the water. It is alive. (Video showing aliveness and swimming at

.) The tail is mostly gone, but I don't see any damage to the other fins, or any spots or marks on the body.

The fish is now isolated in a hospital tank. I have on hand:

Plain salt (NaCl, no iodine, anti-caking agents, or any other additives)

Epsom salt (pure magnesium sulfate, no additives)

API E.M. erythromycin

Paraguard

And it seems to me I remember seeing what's left of the bottle of Kanaplex I got several years ago for a fish with extensive fin damage and sepsis (it didn't help him), but I can't find it right now.

And there's a local aquarium shop that's closing in a few minutes but will re-open tomorrow afternoon.

What do you recommend?

if it has fin rot, how come the tail is in terrible condition, but all of the rest of the fins are in perfect condition? I think that there is more than just the probability of fin rot here, are there any fish that are in the pond that might of eaten the tail, like a bass or a blue gill?

 

[Jim Sinclair]

I think I probably already threw away the Kanamycin. That would explain why I can't find it even though I have a recent memory of seeing it. I probably checked the expiration date and got rid of it.

The fish was just lying on the floor of the hospital tank in the kitchen, trying to blend in and hide in the sand substrate, and ignoring food. Figuring that between being isolated (as a social fish accustomed to having lots of company ever since hatching) and being chilled (the kitchen is the coldest room in the house, even colder than the basement), the poor thing was scared and uncomfortable and generally miserable--not conditions conducive to healing. Since the consensus seems to be that this is an injury and not an infection or parasite, thus not something contagious to other fish, I moved it into the 20 long tank in the living room where it's much warmer and there are other baby fish for company (but no adult ones). I've added salt to that tank (4 tablespoons/20 gallons).

Then this evening I was doing another water change on the tanks in the basement, and I looked over the baby fish in the pond with the adults. Nobody was floating on top like the first tailless fish was when I found it, but I noticed another baby fish swimming with motions similar to how the tailless one swims (over-emphatic spine wiggling to compensate for not having a tail to flip). I netted it for a closer look, and sure enough, this one has a similarly truncated tail, with other fins intact and no spots or marks on the body. I moved it into one of the babies-only plastic tubs in the basement. Maybe I should bring it upstairs too, and put it in the warmer living room tank with the salt.

So now what? Catch all the baby fish in the big pond and check them for tail damage? Remove all the babies from the pond and put them back into tanks/tubs which will become overstocked again? Is there a cheap easy way to cage off part of the pond so the babies are separated from the adults, but water circulation and filtration aren't impeded?

No new homes found yet. Approaching desperation.

If you have old anti-biotics to get rid of, take them to a chemist and ask them to dispose of it properly.

If the tail does get red, inflamed or white and fluffy, post another picture asap and we can advise you on what to use.

Hi, Jim. I think a larger fish bit it as the fins show no damage. I would keep the water clean by doing daily water changes and use aquarium salt. Watch for infection and if it should occur, then you’ll need an antibiotic. I would throw the Kanamycin out if it is several years old as it has lost its potency. Good luck and keep us posted. Found any homes for the babies yet?

 

[Jim Sinclair]

The only fish I have are goldfish. I know big goldfish eat little goldfish, and I had the babies separated until I *thought* they were big enough to be safe. Only the largest ones have been returned to the pond. And apparently they *are* too big to be eaten entirely. Nobody told me the adults would chew up the little ones piece by piece like this.

if it has fin rot, how come the tail is in terrible condition, but all of the rest of the fins are in perfect condition? I think that there is more than just the probability of fin rot here, are there any fish that are in the pond that might of eaten the tail, like a bass or a blue gill?

 

[Cichlid4life]

all fish can chew up just about anything part by part, that is how fish eat food, they chew it just like humans and swallow it part by part.

 

[Jim Sinclair]

But goldfish don't have teeth to bite things! They have pharyngeal teeth back in their throats, but not teeth at the front of their mouths to take bites out of things. I still can't figure out how they're doing this.

all fish can chew up just about anything part by part, that is how fish eat food, they chew it just like humans and swallow it part by part.

 

[Colin_T]

You can make a jumbo sized breeding net out of pvc pipe and mosquito netting from a shop that sells material to make clothing.

You make a frame out of 1/2 inch pvc pipe. You can make the frame as big as you like but it depends on how many fish will live in it and how big the pond is. But you could start with something about 2ft square x 12inches high.

Then get some mosquito net and make a net to go around the pvc pipe. You can either sew a hem on the top edge of the netting that is big enough for the pvc pipe to go through, or just glue the netting to the pipe.

Wash the netting before putting it in the pond and then put the baby fish in it.

The pvc pipe will float if it is sealed up and the netting will allow water to flow through so the fish have good water quality.

 

[Jim Sinclair]

I tried something like that initially when I first introduced the baby fish to the pond, not because I thought they were in danger of being eaten alive, but because I was concerned the adult fish would eat all the fish food before the babies could get to it. I got a big clothes hamper (Sterilite brand, all of whose products, even laundry and storage containers, are made of food grade plastic), with holes big enough for the babies to go in and out but too small for the adults. It's still in there, and a lot of the babies go into it to eat. Initially I tried lining it with netting to give the babies a chance to get used to the fact that this is where their food is served. The fish seemed agitated and uncomfortable in the netting-lined hamper, as if something about it were irritating them. When I removed the netting the fish acted calmer and not distressed. But of course this means the little ones can swim in and out freely, so it's not keeping them from being chewed on.

So how do you recommend washing the netting? What I did was first soak, swirl, and wring it in a solution of white vinegar in tap water, then immerse and agitate then hold it under the tap and wring it in plain tap water to rinse out the vinegar, then immerse and agitate it in Prime-treated water to get rid of chlorine from the tap water. I did all this in one of the buckets (originally a bulk food bucket, so fish-safe) that I use for moving fish and temperature-equalizing fish water. I didn't want to put the netting into the washing machine, or even into the sink, for fear of detergent residue. How would you clean netting to make it safe for fish?

You can make a jumbo sized breeding net out of pvc pipe and mosquito netting from a shop that sells material to make clothing.

You make a frame out of 1/2 inch pvc pipe. You can make the frame as big as you like but it depends on how many fish will live in it and how big the pond is. But you could start with something about 2ft square x 12inches high.

Then get some mosquito net and make a net to go around the pvc pipe. You can either sew a hem on the top edge of the netting that is big enough for the pvc pipe to go through, or just glue the netting to the pipe.

Wash the netting before putting it in the pond and then put the baby fish in it.

The pvc pipe will float if it is sealed up and the netting will allow water to flow through so the fish have good water quality.

 

[Colin_T]

I would just wash it by hand in a bucket of soapy water. Then rinse well. As long as you use a perfume free soap and rinse it well it should be fine. You could do the same with a washing machine and just give it a couple of short washes with laundry powder, then give it a couple of washes with water only.