5 ways of How To Euthanize A Fish? All You Need To Know

In any event, before learning how to euthanize a fish, you must first be able to tell when a fish needs to die and when it should not. As aquarium fish vary widely in size and tolerance to varied conditions, no one procedure can be regarded as ideal for euthanasia of all aquarium fish varieties.

For instance, temperate, tropical, fresh, and saltwater. Aquarists must make several challenging decisions, ranging from the size of the fish tank to the placement of plants, rocks, and driftwood surrounding the tank, as well as the species that will reside inside. The most agonizing decision an aquarist will ever have to make is whether or not to euthanize their fish.

Furthermore, scientific research evaluating the humaneness of various techniques of killing fish is limited, making it difficult to tell precisely how particular humane approaches are. If you’re reading this, it’s possible that your fish is suffering from an illness from which it will never recover or that your fish has simply reached the end of its useful life and is now dying to old age.

Table of Contents

When And Why Do You Need to Kill A Pet Fish?

An aquarium may be dangerous for fish. Especially if they aren’t entirely adapted to the surroundings. When you have fish in your aquarium, one species may attack or harm another.

The beaten fish becomes ill and harmed as a result of this. As a result, recovery is nearly difficult. As a result, it’s preferable to put it to rest for good.

Another reason to kill your fish is infested with pests such as hydra, columnar, or freshwater itch. Your fish will become unwell as a result of these bugs. Furthermore, if you recently introduced untreated tap water to your aquarium, the pH shift may impact the fish’s life.

Unfortunately, effectively reviving your fish is not feasible. The best solution will kill it when it becomes unwell and does not recover for a long time.

How Do You Humanely Kill A Pet Fish?

When discussing the best approach to assist your fish die gently, emphasize the term “humanely.” We’ll look at a couple of humane ways to kill a pet fish.

how to euthanize a fish

Many of the ways for dispatching your fish listed below are commonly utilized by veterinarians. However, there are several that you may use at home safely and straightforwardly:

Euthanize Your Fish With Baking Soda

Some hobbyists have suggested baking soda as a way to kill fish. Combine one spoon of baking soda with 1 cup of water to form a solution. Fill a clean container halfway with the solution and your fish. The fish usually dies within 15 to 20 minutes.

Benzocaine hydrochloride 

Benzocaine hydrochloride is a veterinary drug that you can only receive from your veterinarian on prescription. The American Veterinary Medical Association (AVMA) exclusively recommends Benzocaine hydrochloride, not plain benzocaine.

Because benzocaine is not water-soluble, mixed with ethanol or acetone, which harms fish tissue.

Clove Oil/Vodka Method

There are several articles on the internet recommending the use of clove oil or vodka to anesthetize fish. However, because overdosing the fish with clove oil would not kill it, the procedure also requires an alternate way of killing the fish once it has been anesthetized.

Because of a lack of study, the AVMA does not recommend using clove oil for fish euthanasia or killing a fish with vodka or rubbing alcohol.

Tricaine Methanesulfonate (TMS)

Universities and veterinarians frequently employ this approach of humanely euthanizing fish.

To acquire the optimum dose rate and the quickest manner to dispatch your fish, strictly follow the manufacturer’s instructions. The entire way will take less than 20 minutes and was quite effective.

Death By Injection – Barbiturates

A fish can euthanize by injecting an excessive amount of barbiturates into its circulation. Essentially, the fish falls slumber and passes away softly.

Because other barbiturates induce discomfort when administered, the AVMA recommends Sodium Phenobarbital as the medication of choice for this procedure.

Only veterinarians should use this technique of euthanasia, partially because the medicine is difficult to get without a prescription, and it’s also challenging to administer appropriately.

How NOT to Kill Your Fish?

The techniques for euthanizing a fish outlined above are all compassionate. A brief internet search shows a plethora of methods for killing your pet fish. However, only a handful of them is genuinely compassionate.

There are a variety of techniques for euthanizing fish that we don’t support since they aren’t compassionate, like: 

Carbon Dioxide

Carbon dioxide can smother your fish if you introduce it into the water. However, this is a lengthy, painful procedure that is highly distressing and not at all humane.

Alka Seltzer

Alka Seltzer is frequently recommended as a method for euthanizing fish. The fish is placed in a sealed container, and then Alka Seltzer is added to the water to drive away from the oxygen, thereby smothering the fish.

However, because acidosis can ensue, resulting in a protracted and painful death for the fish, the method has been outlawed on EU fish farms. As a result, we do not advise adopting this strategy.


Smaller fish species can face beheading, but the brain must be destroyed afterward. The procedure involves “pithing,” which involves piercing the brain with a sharp tool and destroying it.

Before you decapitate the fish, you must always pith it. Although the fish will die, its detachable head will most likely remain alive and conscious for a few minutes later.


On the surface, freezing a fish appears to be a somewhat gentle method of killing your fish.

That, however, is not the case! When placed in cold water, all fish can suffer from temperature shock, while coldwater species like Koi and goldfish can live at frigid temperatures.

Also, don’t try to kill your fish by placing it in the freezer! Ice crystals will grow fast on the fish’s gills, causing the poor creature excruciating suffering.

Snapping The Neck

Although cracking the fish’s neck may appear to euthanize it, the spine of a fish is incredibly flexible. Breaking the spine won’t work unless you also pith the brain.

Furthermore, this method does not ensure that the fish will die fast or at all, resulting in a long, agonizing death for the fish.

Flushing Your Fish

Although flushing fish is a common way of disposal, it is a harsh technique that we do not encourage. When you flush a tropical fish, the temperature and quality of the water will drastically alter.

When the fish ultimately drowns in sewage, it will most likely have a horrible and stressful end.

Stab and stun

One efficient way of killing a fish is to shock it with a blow to the head and then complete the job with pithing.

However, your initial stroke must be precise and efficient; else, you risk inflicting agony and suffering on your unfortunate fish. Some enthusiasts prefer to anesthetize the fish before striking it in the head with a powerful blow.

Boiling Water

There is no scientific proof that plunging a fish into boiling water is an effective killing technique. The widespread agreement is that boiling a fish alive is considered one of the most painful methods of euthanizing a fish.

Again, boiling your fish is not an appropriate means of murdering your fish.


If you’ve ever had a fish that leaped out of its tank and laid undetected on the floor for a long time, you know that suffocation is not an acceptable manner of dying a fish.

Suffocation is a gradual and painful process that produces muscle discomfort, gill damage, escape reactions, and organ failure in fish.

Additives For Euthanizing Or Healing Your Fish

The primary additive for euthanizing or healing your fish:

Clove Oil: Mix a few drops in a glass of water well. Combine the ingredients in a container with the fish. Don’t add drops to the container containing the fish. First, combine the ingredients.

Baking Soda: 1 spoonful of oil to 1 cup of water Combine the ingredients in a container with the fish. Do not put baking soda in the fish container. First, combine the ingredients.

Stress Guard: Stress Guard may help cure and increase the health of your aquarium’s fish, whether it’s to avoid future disease or to treat a sick fish.

Immune Support: Another excellent ingredient for keeping your fish and corals healthy. It’s also helpful in rehabilitating ill fish.

Should I remove dying fish from the tank?

Convinced your fish will die soon? It would help if you got a container ready for them. When it comes to dealing with your fish, you should use one of the ways listed below. However, you’ll want to figure out what brought your fish to this stage.

If you have any doubts, examine the water quality and search for evidence of damage on the fish. Is there something developing on your fish that wasn’t there before? Are there any scars or other injuries on your body?

Depending on the reason for damage to your fish, you’ll want to address the issue right once to avoid more fish suffering from poor water quality, temperature surges, or disease.

How to comfort a dying fish?

You may want to make your fish as comfortable as possible while arranging a space for them or preparing the essential items.

You may attempt to keep loud noises to a minimum because fish are generally sensitive to noise, but keeping other traumas minimal will be helpful because they are already going through a stressful event.

When you’re ready to relocate your fish, do it with the same care you’d give it if it were going to live another few years. Avoid shocking it by submerging it in ice-cold tap water. After all, you’re aiming to create a safe environment for it to move through in peace.

When should you euthanize a fish?

You may need to put your fish down for various reasons, like accidentally putting the wrong water in the tank or being harassed by another fish. A fish may need to be put down for various reasons, so it does not have to suffer any longer than necessary.

It implies that you should always look for changes in a fish’s feeding, swimming, and color. Depending on the symptoms, you just have one option for your fish: put it down as gently as possible.

How does a vet euthanize a fish?

Most likely, your veterinarian will use an anesthetic overdose, which is often used on larger fish. Still, depending on your veterinarian’s choice and the fish species, they may use a different procedure.

If it makes you uneasy or too sad to do it yourself, you can take your fish to the vet to be put down, but as we all know, going to the clinic for anything is expensive. If you learn to euthanize your fish promptly and gently, you will save money in the long run.

How to euthanize a fish with clove oil?

Clove oil is a sedative that may be used to euthanize tiny fish in excessive dosages. Clove oil, unlike veterinary anesthetics, is widely accessible in pharmacies. Exposure to around 0.4ml of clove oil per liter of aquarium water is enough to kill exposed fish.

Clove oil in a glass sauceboat on a white background. Spice cloves in a gravy boat.

Before carefully adding the clove oil to the aquarium water housing the fish, mix it with a little warm water first. Because fish become excited when they see clove oil, don’t add it all at once; spread it out over 5 minutes.

When fish are exposed to this concentration of clove oil, they lose awareness, cease breathing, and die of hypoxia.

Please keep in mind that the solution’s concentration must be adequate for the fish’s size, and the fish must stay in the solution for at least 10 minutes after all signs of gill movement have stopped.

When all signs of gill movement have ended, place the fish in the freezer until it is completely frozen. It will ensure that the fish is dead and can be securely disposed of it. Clove oil, like the anesthetics MS-222 and benzocaine hydrochloride, can help people die peacefully.

On the other hand, clove oil appears less unpleasant to fish than MS-222, implying a more merciful death.

how to euthanize a betta fish with clove oil?

Exposure to around 0.4ml of clove oil per liter of aquarium water is enough to kill exposed betta fish.

Before carefully adding the clove oil to the aquarium water housing the betta fish, mix it with a little warm water first. Because betta fish become excited when they see clove oil, don’t add it all at once; spread it out over 5 minutes.

how to euthanize a fish with clove oil and vodka?

A two-step procedure is the most effective. To guarantee the fish does not wake up, first anesthetize it with clove oil to be asleep and unable to sense pain; then inject it with clear grain alcohol such as vodka. The fish is anesthetized with clove oil.

how to euthanize a betta fish with baking soda?

Baking soda is a humane way to put down your betta fish that is more common and available in every household. When you’ve tried all methods for your fish and failed every time. Now is the moment to accept the truth that your betta fish is at a place where there are no returns.

Baking soda

Soothe the betta fish and put it down as gently as possible. Baking soda creates a significant rise in the amounts of carbon dioxide in the water. It depletes oxygen and causes a rapid loss of consciousness.

Within 20 minutes, your betta fish will begin to slow down, and after a while, it will cease moving altogether. This method just takes a spoonful of baking powder and a cup of water when done correctly.

First and foremost, you must isolate your betta fish in a separate tank. After that, take the cup of water and thoroughly combine the baking soda with it. Now, pour the solution into the tank with the dying fish.

how to euthanize a fish by freezing?

When it comes to euthanizing warm-water fish, freezing is a typical procedure. Freeze water in a tiny bag until it gets slushy to freeze your fish. After that, submerge your fish in water and continue to freeze it.

how to euthanize a fish with ice water?

Glass, Water, Ice Cubes, Drink, Cold

Tropical fish under 2 inches long can get killed by submerging them in ice-cold water. The fish is placed in a tiny container with aquarium water that is kept at room temperature. After that, the container is placed into a much bigger container filled with crushed ice.

how many drops of clove oil to euthanize a fish?

Inducing euthanasia in fish is as simple as putting 12 drops of clove oil in a gallon of dechlorinated water. Because clove oil is insoluble in water, an emulsion is made by combining a tiny amount of water with 12 drops of clove oil in a leak-proof container.

To make a suitable emulsion, you must violently shake the jar. To comprehend how to euthanize fish using clove oil properly, you must first know the exact amount of clove oil needed to euthanize a fish.

how to euthanize a fish with alcohol?

Still life. pour or whiskey into glass.

It’s one thing to intoxicate the fish once as it would with a human. But the fish will be exposed to the alcohol all of the time since it’s floating in the water they breathe. Your pricey aquarium fish will perish if they consume alcohol.

how to euthanize a saltwater fish?

The best technique to euthanize saltwater fish is to freeze them. Clove oil suffocates them over time. In the end, a fish’s neural system is just reactive; it does not “experience” pain in the same way that we do.

Proper disposal is essential, and the best method to prevent introducing anything into the local ecology is to dispose of it by fire.

how to euthanize a betta fish with vodka?

Some may consider the use of vodka to euthanize betta fish to be cruel. However, people say it without understanding the specifics.

To begin, you’ll need clove oil in addition to the vodka. Wondering why clove oil is required for this procedure? It may surprise you that the clove oil mixture may not always be effective in euthanizing your fish.

Many fish owners have found themselves in this scenario and are unsure of what to do. So, once you’ve finished with the clove oil, pour vodka into the designated container. Remember, the ratio of vodka to water should be 1:4.

Pour no more vodka into the water tank than this quantity. Now to speak, why it’s not a cruel procedure. The critical thing to remember is that because of the anesthetic action of the vodka.

Your fish will already be unconscious when you add it. Your finny companion will euthanize you as soon as you add vodka.

how to euthanize a fish without clove oil?

The ways to euthanize a fish without clove oil are the following:

  • Baking soda
  • Boiling water
  • Vodka
  • Carbon dioxide
  • Ice

how to euthanize a betta fish without clove oil?

To euthanize a betta fish without clove oil, follow the methods mentioned below:

  • Blunt object
  • Carbon dioxide
  • Alcohol
  • Decapitation

how to euthanize a parrotfish?

For euthanizing parrotfish, place them in a container. Put the water and fill the crushed ice. Your parrotfish will be euthanized. 

How to euthanize your fish with baking soda?

Yes, you can euthanize your fish with baking soda. Make a solution with one tablespoon baking soda per cup of water, and then add your fish to it.

It will take 15-20 minutes for the fish to cease moving entirely. This procedure is both more compassionate and more accessible.

How to euthanize a fish with vodka?

If you don’t have any clove oil on hand and won’t get it in a reasonable length of time, you may use vodka instead. This procedure is not very compassionate because the fish may get injured before it loses consciousness.

To use this approach, mix 1 part vodka with four parts water and submerge the fish in it. Alcohol poisoning can cause the fish to pass out and die. 

What to do with unwanted aquarium fish?

If your fish isn’t dying, but you no longer want it, you should try to find it a new home instead of killing it. You may try contacting a local pet store to see if they will buy it from you, but even better if you know another aquarist who could be interested in that particular fish.

You might contact other residents in your region who may have saltwater tanks to ask if they’d appreciate some free fish. Since you took on the initial obligation of caring for your fish, you should be trying your best to find a new home, just like any other pet.

Like cats and dogs, fish rely on you to look after them to the best of your abilities, and you accept that duty when you begin the pastime.

How To Humanely Euthanize A Betta Fish?

Due to the betta fish’s small size, there are numerous techniques for inducing euthanasia for your ill betta fish. Clove oil is a suitable option because it is inexpensive and produces rapid death.

Fill a jar halfway with dechlorinated water and a few drops of clove oil. Add 12 additional drops of clove oil to a small amount of dechlorinated water in a separate container and shake vigorously.

As clove oil is insoluble in water, this will aid in creating an emulsion. Transfer the emulsion to the original container holding a few drops of clove oil. Combine all of the ingredients well. Place your fish in the container and wait 30 minutes to see what happens.

Examine the fish for any possible movements. If the betta fish does not move, it has been successfully euthanized.

How to Dispose of a Deceased Fish?

Many people believe that you should just flush dead fish down the toilet. At least the tiny ones. However, don’t do it. Fish that have been caught can end up in nearby rivers. The germs, viruses, or parasites that killed them might then be passed on to local fish.

It might have disastrous consequences for local fish populations. Instead, put the fish in a plastic bag and toss it in the trash. It’s always best to stay careful and safeguard wild fish wherever possible.

Inhumane Euthanization Methods

The inhumane euthanization methods are the following:

Blunt object or a knife

Place the fish on a layer of aluminum foil and wrap it in another sheet of aluminum foil. You should hit its skull as hard as you can with a blunt, heavy instrument. The caution is that you succeed if you do not hesitate and aim well.

If you’re not sure you can accomplish it, try an alternative approach. You may also try chopping into the middle of your fish’s skull with a knife if you want a better understanding of how to accomplish it before doing.

If done correctly, it is painless, but you must know what you’re doing.

Flushing your fish

Flushing your fish does not ensure that it will die. All you’re doing is sending your fish to a different location to perish.

You are absolving yourself of responsibility. It will die a slow death in sewers or even in a water treatment plant, so this technique of “killing” is best avoided.

Carbon Dioxide

Sure, you can kill your fish by injecting carbon dioxide into the tank, but that won’t help you compassionately kill them.

This approach, like flushing down the toilet, is used when you don’t care about your fish since the fish isn’t lulled to sleep but instead gasps for breath until they pass. It’s probably best if you don’t use any water at all. To euthanize your fish, don’t suffocate it.

How to Tell If the Fish Has Passed?

You must confirm that a fish is dead before throwing it, regardless of the humane manner you employ to kill it. You may verify it in a variety of ways.

Here are several examples.

  • If you killed the fish using clove oil and an overdose of anesthesia, keep an eye on it. It’s dead if you discover it on top of the container or at the bottom.
  • You should also look for evidence of movement coming from its gills. Your fish is no longer alive when it stops moving.
  • Gently touching your fish is another option. When scooping out the fish, make sure to use a net. It’s still alive if it travels away. Otherwise, it’s no longer alive. Then scoop it out and discard it.
  • Examine the eyes. To declare dead fish’s eyes must be sunken into its skull and gray-colored.
  • Finally, if the fish has been stabbed, it will cease moving after dying. Before you dispose of it, wait 30 minutes to be sure it is entirely dead.


Understanding how to euthanize a fish is only one-half of the puzzle. An essential thing to learn is properly caring for your fish, so you don’t have to euthanize them anytime soon.

If the time comes for your fish to pass away, you may rest easy knowing that you did all possible to ensure that your fish enjoyed a long, healthy, and happy life.

As painful as it is to put your fish down, it is for the best in terms of suffering and anguish. Before you decide to euthanize your fish, be sure you’ve tried all of the available drugs and therapies.

Clove oil is the most effective and efficient technique. Some of the more aggressive and less popular treatments include freezing and stunning. 


What is the quickest and most humane way to kill a fish?

The clove oil technique of euthanizing the fish is the quickest and most humane form of euthanization. When the fish is in a condition of slumber, it will die in this technique.

How do the Japanese kill fish?

By putting them in freezing water to cool them down (a method known as no-jime). You can shock the fish, then stab them in the head and let them bleed out in the water through a gill incision (standard ikejime).

How do you put a fish in its misery humanely?

By using clove oil for their euthanization, you put a fish in its misery humanly.

How do you kill a pet fish instantly?

Decapitation. Stunning a fish, decapitating it, and then pithing it (physically damaging the brain with a metal rod) is an instant technique to euthanize a fish. The pithing procedure is necessary because fish can stay awake for an extended period after being decapitated.

About the author

I'm Gulshan, a passionate pet enthusiast. Dive into my world where I share tips, stories, and snapshots of my animal adventures. Here, pets are more than just animals; they're heartbeats that enrich our lives. Join our journey!thing.