Can You Flush A Dead Fish Down The Toilet? – How To Handle Dead Fish

I was talking the other day with a friend about fish tanks when we were kids. My friend mentioned that his fish all of a sudden disappeared. He told me that his parents flushed the dead fish down the toilet. I’ve heard it before but didn’t make sense to me so I decided to ask myself:

Can you flush a dead fish down the toilet? You should never flush a dead fish down the toilet. It may harm the ecosystem in the water where you live. It’s better to dispose of the dead fish in the garbage.

I got really concerned that this is a common practice, I have heard it before, so I decided to go through what happens when you flush dead fish down the toilet and what to do instead.


The main reason to not flush dead fish down the toilet is the risk of spreading diseases to other animals or even humans.

There is a reason for the fish to die. A very common reason is that the fish die from a disease. Most diseases you get in a fish tank are deadly for fish. The diseases are caused by parasites and bacteria.

A lot of diseases are very contagious. In the fish tank, the parasite or bacteria are only able to infect other inhabitants in the tank. But if you flush it down the toilet the dead body of the fish is transporting the infection into the sewer system and might infect other animals and critters living in there.

The parasite or bacteria are also able to get out with the water, into our rivers and lakes and might infect other fish or animals living in our environment.

Even if it’s not a disease the fish are dying from it’s not a good idea to flush it down the toilet. You could never be certain that it’s not a disease that is killing the fish. In this case, it’s better to be safe than sorry and not flushing it down the toilet.

The water going through the pipes in the toilet is going to a water treatment plant which removes the solid matter coming down the pipes and also removes anything harmful in the water before disposing it into the environment.

The water treatment plants are not designed for removing fish diseases which could make the bacteria and parasites go through the plant into the water and then infect the environment.

How effective the treatment plants vary in different parts of the world. In some countries, the water would probably be free of any disease when put into the environment but in other countries, it might not.

The worst is that an infected fish flushed down the toilet might infect rats and cockroaches living in the sewer, which will then be food for other animals, and that animal is getting infected.

How it affects the ecosystem

Flushing down dead fish into the toilet is threatening the ecosystem where you live. The fish itself will be taken care of in most countries. There is a risk of other creatures from the fish tank is going down with the fish and might survive.

When a fish dies the other inhabitants in the tank start to eat the fish. That includes other fish, snails, and shrimps. The snails are very quick to the fish and start to snack on it. They could even lay eggs on and inside the fish if the fish have been dead in the tank for enough time.

The snail eggs are very sturdy and can survive in a lot of conditions. Chlorine will, however, kill the snails which are very common to clean sewage with.

The snail eggs could hatch before the fish body can get to the treatment plant, depending on how long the fish has been dead. This should however not be a problem. Snail eggs take between 1 to 4 weeks to hatch and within that period of time, you would probably have found the dead fish and removed it.

There is another problem with snails when flushing fish down the toilet though. There could be living snails on or inside the fish body.

These snails could be stuck in the pipes and crawl out into the environment. As you might have seen in your fish tank, the snail is very quickly reproducing in the fish tank.

If the snails get a grip inside the pipe, they could reproduce inside the pipe or find their way out into a lake, river, or the ocean and start to reproduce there.

If the snail is not normally in that environment the snail could outcompete the other species of snails and thus making a problem in the ecosystem potentially wiping out other species too.

If a disease from the fish you flushed down the toilet is getting into the environment it could also wipe out certain species potentially threatening their existence.

This is a very serious problem by flushing down dead fish into the toilet!

The potential of damaging the variety of species in our water is a serious threat and will come back to us.

If some species are wiped out, it will damage other species that are eating the wiped out species. And that species will affect the other and so on. It goes like that all the way down the food chain until it reaches us humans and we could find a shortage in food if too many species are extinct.

All this because you flushed a dead fish down the toilet, instead of disposing of it the right way.

Problem with living fish in the toilet

You should never put anything living down the toilet pipes! That includes fish!

There are some problems with flushing living fish down the toilet. First of all, the fish might survive the trip and get into the environment.

This is highly unlikely unless you live in a place where the sewage is disposed directly into the environment. This is not good for the environment, so chances are that you are living in a country where they treat the sewage water one way to at least get rid of solids going down the pipes.

The fish will be taken care of on its way down the pipes and the fish will die from the trip.

It is very inhumane to kill a fish by flushing it down the toilet alive. If you have to kill a fish because it having a disease that is not treatable you should do it quickly to not let the fish suffer. The fastest way is to hit the fish in the head with a hard hit.

The fish you flush down alive will not be able to swim back up. The flow of water is too heavy for the fish to resist.

If you do this, the fish will get really stressed. That will kill the fish and the fish will suffer a lot when it is this stressed.

Think yourself how it would be if you were put inside a dark, stinky tube. It would not be a nice environment to be in and you would get really stressed.

The feces and everything else flowing down the pipes are a very hostile environment for the fish or anything for that matter. This adds to the stress for the fish. The bacteria in the pipes (which are a lot of them) are also attacking the fish making it even more stressed.

To flush a living fish down the toilet is one of the most inhumane things you could do to your fish. It will stress the fish a lot, killing the fish on the way. If the fish, miraculously enough, survive the trip, it could damage the ecosystem.

If you have to kill a fish, do it more humanely and kill it with a hard hit to the head. That kills the fish instantly and it will not suffer. It’s harder for you to do it but the fish will be in a better place if you do it this way. Then dispose of the fish the right way, and don’t flush it down the toilet!

Stopping the pipes

In some places, there is a risk of the dead fish making a stop in the water lines. That is if the sewage pipes are too small to handle everything going down it.

If this is the case you will probably experience stop in the sewage system regularly.

It is still unlikely that a small fish will cause a blockage in the sewage system. most fish kept in a fish tank is only a couple of inches long and are small enough for even the narrowest sewage pipes.

There are some problems if you flush down bigger fish though! They could cause a blockage in the pipes of the toilet. Most toilets have a water lock.

That’s the bend you will see while looking where the water is going where there is some freshwater collecting, preventing the odor to come up into your house from the sewage system.

A big enough fish could get stuck in that bend making a blockage in the toilet and will give you problems with flushing anything down after that without calling a plumber.

A bigger fish could also be a clog in the sewage system even if it gets through the water lock of your toilet.

If the pipes are a little bit damaged, or if there are build-ups in the pipes, the dead fish could get stuck on that and make other solids going down the pipe get stuck on the fish, making a mess.

Again this is not very likely but it is a possibility, depending on how developed the sewage system is where you live.

If you live out in the countryside, chances are that you have a septic tank instead of being connected to the sewage system.

The septic tank is containing microbes that decompose everything organic getting in. Well, dead fish are organic but not very easy to decompose for the microbes.

The microbes are used to (and is their primary task) decompose soft waste. Dead fish are not soft since they are not cooked in any way. This makes the microbes work a lot more to be able to break the dead fish down.

This might be a problem since the microbes will then not be able to keep up with the waste coming down into the tank and it builds up. This could cause a “clog” in the tank.

This will make you need to get someone to come to you and clean the tank, costing you money that you shouldn’t be needing to spend.

How to dispose of dead fish

It is very hard when a fish dies. You often build up a relationship with your fish. It’s even harder if you have to kill a fish yourself to stop its suffering.

This is something every fish keeper has to handle at some point in their fish-keeping career. Fish will die and you should not let them be in the fish tank when dead.

That because there is a risk of diseases spreading, killing every other fish in your tank. The other inhabitants will start to eat the dead fish too. That’s inhumane and will increase the risk of your other inhabitants getting sick.

The dead fish will start to decompose and that will be damaging for the fish tank too. Therefore it’s important to get rid of any dead fish as soon as you find one dead.

Once you picked up the fish from the fish tank you have three ways of getting rid of it. None of them are flushing it down the toilet.

The first thing you could do is bury it. Dig a hole in your yard and give it a proper funeral. This is a very common suggestion.

However, I will not recommend this method. There is a risk of other animals dig your fish up and feast on it. If you go with this method you should dig a deep enough hole and put a rock or something similar on top to prevent animals from digging the fish up.

This will also prevent the odor that will be noticeable when the dead fish will start to decompose. That’s not a smell you want in your backyard, that’s for sure!

This leads to another problem with this method. As mentioned before, the fish might have died of a disease and if you bury it the bacteria or parasites that have infected the fish could go down into the groundwater.

When it rains the water will go down through the soil into the groundwater. If the infected fish is in the way, the water might bring the bacteria and parasites down with it into the groundwater and the rivers and lakes potentially infecting other animals living there.

So, if I cannot bury or flush the fish down the toilet, what should you do? There are two ways that are a lot better and what you should do when you getting rid of a dead fish.

The first way is to throw it away with the trash. With this method, the fish will go with your other waste to a dump where they usually burn the fish or it could get converted into biofuel.

In the garbage can, the fish will decompose and you have to put it into a bag that you seal properly. You don’t want the smell of rotting fish in your house. A zip lock bag should do it and if you want to be sure, put it into two bags.

Your garbage man will be thankful too. They endure a lot of stinky smells during the day, please don’t add another stinky smell into their workday.

The second way is to cremate the fish. This way you should not be a part of spreading diseases into the environment and this is the way most garbage is eliminated.

All you have to do is to make up a fire and throw the dead fish into it. It will not take long for the fish to burn up into ashes.

This will also get rid of any bacteria or parasites preventing them from spreading into the environment.

As with all of these methods, be sure the fish really is dead! If the fish is almost dead it will be a lot of suffering for the fish no matter which method you choose to dispose of the fish.

To be sure, hit it in the head before getting rid of it. That is actually the most humane thing to do.

Whatever you do, don’t throw a dead fish into the environment or in the water! This will most likely spread disease and potentially threatening the wildlife.

How to tell your kids

Now you know you should never do as my friends’ parents did, flushing fish down the toilet. But how should you tell your kids that the fish died?

A lot of parents are telling their kids to flush dead fish into the toilet. That’s probably because it will be easier for the kid to not having to kill it and look at it dead for a long time.

If you throw it into the toilet and flush the fish will be gone in an instant. Also, the fish lives in water, it’s easier to tell a kid that the fish should be in water even after death.

Don’t do it too easily for you or your kids. Sometimes life is hard and you should face these moments and you (and your kids) will come out stronger when facing these hard moments in life.

A lot of parents are also throwing the fish away and replace it with another fish.

This is a good opportunity for the kid to learn about death. Nothing lives forever and to teach a kid about death at an early age is giving the kid an understanding of what life and death are.

To replace the fish is a viable option if the kid is very small. Then the kid will not find out that it’s a new fish swimming there.

But if the kid is a little bit older they might notice. In that case, it’s better to be completely honest and tell the kid the fish died and you will get a new one.

You could also let the kid be a part of the handling of a dead fish. Just do it with respect and the kid will also learn to be respectful to the dead ones.

Since fish has such a short life span, it’s inevitable for fish to die if you have a fish tank. Use this to your advantage and be open with the death to your kids and teach them about death and how to show respect to the dead ones. Both animals and humans.


There are some reasons for you not to flush your dead fish into the toilet.

The main reason is to not spread diseases into the environment. This could be fatal to the animals living in the area around you is a big problem worldwide.

The fish died for a reason, disease is a very common reason for fish to die. The water is getting cleaned in most places of the world and is usually removing the bacteria and parasites from a dead fish.

The cleaning is not meant to clean fish diseases and bacteria can mutate and be resistant. To prevent the bacteria to be resistant to the methods we have to clean our sewage water it’s best to lower the number of bacteria from the beginning.

To lower the number of bacteria it’s best to not flush it down the toilet.

A dead fish could, if big enough, cause a blockage of the sewer pipes in some places. That usually where the sewage system is not as developed as in many countries.

If a blocked sewage pipe breaks it could cause damage of millions of dollars. That would be a really expensive flush if it’s you who flushed down a dead fish.

Lowering the diversity of animals is a serious problem in many parts of the world. Flushing down living fish or dead fish for that matter is adding to that threat.

Some species from a fish tank could outcompete other species that live in the biome where you live if they get out from the fish tank. That’s no good and could, in the end, be a problem for us humans.

A better way to get rid of a dead fish is either to bury it, throw it away with the trash, or burn it.

All three are viable options but I would not recommend burying the fish due to the risk of it spreading diseases.

Also, note that it might be illegal to flush fish down the toilet in some places. The same goes for burying or burning the fish. To be sure check your local laws to be sure that you do the right thing.


I have been a fish keeper a big part of my life. During the years I have gathered and searched a lot of information about fish keeping and here, on the website, is where I share that information to help you with your fish keeping. I want to provide the information that I didn't get when I had a question about my fish tank.

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