How to Euthanize Your Snails and Shrimp Humanely

How to Euthanize Your Snails and Shrimp Humanely

Losing pets always suck. Nonetheless, in some cases, we even have to make a decision on how to put them out of misery so they can rest peacefully. Not fair to any animal to let them suffer. Therefore, I have to bring up this unpleasant topic.

A quick and stress-free method to put your snails and shrimp to sleep at home is using decarbonated beer or clove oil and placing them into a freezer, formalin, or high concentration of alcohol.

This article will explain to you the entire process of humanely euthanizing your snails and shrimp at home.

No help from the outside …

Unlike many other pets, snails and shrimp do not have any veterinary services.

Really, has anyone else seen a vet that will look at dwarf shrimp? As for the snails, it is even worse because many snail species have a reputation for being pests. No surprise why vets have not been taught ‘snail care’.

Thus, we simply cannot take snails or shrimp to a veterinarian for humane euthanasia. We cannot take them to animal shelters as well, they do not do that.

Unfortunately, we are alone in this matter. 

Do Snails and Shrimp Feel Pain

Pain is cruel. Of course, nobody wants their pets to go through the pain. But do snails and shrimp feel pain like humans do?

The main problem is that definition of pain cannot be fully applied to invertebrates because of their nervous system.

For many years, even scientists did not think that invertebrates could feel pain. In their studies, they presumed that these animals simply reacted mechanically. In other words, there was no implication that central processing and decision-making are involved in responses. 

Nonetheless, according to the latest research, it is believed that invertebrates may experience pain (just not in the same way humans do).

As a result, Switzerland became the first country that elected to legislate for lobsters to be stunned or knocked out prior to boiling them. This way they won’t feel any possible pain.

So, do snails and shrimp feel pain? Yes, they do, therefore, we have to act accordingly.

Related article:

How to Euthanize Your Land and Aquatic Snails Humanely

Interesting fact, land snails are attracted to beer. Based on this, scientists suggested using their weakness to alcohol o humanly kill them.

The process consists of 2 steps:

  1. sedative,
  2. finishing.

During the first step, a decarbonated beer or 5% ethyl alcohol solution sedates the snails. Snails should be left there until completely immobilized. Generally, it takes around 20 – 30 minutes.

Interestingly, snails like beer. They keep absorbing it until getting ‘drunk’ and pass out. After that, snails should be immediately placed in (options):

  1. 10% neutral buffered formalin, or
  2. 70% to 95% ethanol.

If you do not have any of these liquids, you can simply freeze the unconscious snail so it dies while it is sleeping.

Note: If snails are not immersed into formalin or high concentration of ethanol, they will slowly recover over a 2-h period.

Basically, the process is much like that used with domestic animals, when a veterinarian sedates a dog or cat before administering a final dose of a euthanasia drug.

How can we be sure that snails do not suffer?

To answer this question, we need to observe and compare their behavior under various stress conditions. For example, experiments showed that:

  Conditions Behavior Time
1 RO water Test group – normal behavior. It means that snails:

  • moved around as usual,
  • did not retract tentacles,
  • did not release bubbles or mucus on contact,
  • no defecation.
 
2 Beer (4.74) and 5% ethanol Normal behavior until immobile. 20 min
3 70 % ethanol Aversive behavior until death:

  • retracted into the shell,
  • produced bubbles and mucus on contact,
  • immediately expelled feces.

Note: These are all signs of stress, anxiety, or pain in invertebrates.

30 min
4 95 % ethanol Aversive behavior until death:

  • retracted into the shell,
  • produced bubbles and mucus on contact,
  • immediately expelled feces.
10 min

As we can see beer and 5% ethanol did not change the behavior whereas the other options had a very negative effect until their death.

A few more options for aquatic snails:

In addition, anesthetic overdosing with magnesium salts, clove oil, or eugenol is also recommended for aquatic invertebrates.

  • Magnesium salts. According to some studies, snails are is unable to distinguish toxic metal from essential metals. High levels of magnesium (>1500) make snails lethargic, stop moving and start falling off the surfaces. Eventually, it will also kill them but it will require hours.
  • Clove oil (Eugenol). This oil has the active ingredient eugenol, which is a natural anesthetic. Eugenol has an anesthetic effect on snails. They become numb and lethargic.
    Step-by-step process:
  1. For sedation, add 5 – 10 drops per gallon (~ 4 liters) of warm water.
  2. Mix the clove oil with water. Shake it up if you have a lid on your jar.
  3. The liquid should become milky-looking.
  4. Put snails into this liquid.
  5. Wait until they stop moving. It usually takes a few minutes.
  6. For euthanizing, you need to leave them in the clove oil for 5-10 minutes more.
  7. Or you can put the jar into the freezer, to make sure that snails have been successfully put down.

Note: Keep in mind that clove oil is not completely soluble in the water below 60°F (15°C).

If you want to minimize suffering and tissue damage, do not simply go with the freezing or boiling method.

Even though these methods are relatively fast and simple, they are not painless and during the last moments of their life, snails will still feel pain.

 How to Euthanize Your Shrimp Humanely

I am pretty sure that there are many people out there who would simply say – It is a shrimp for Godsake, just kill it!

Well, we are not all made of stone. For some of us, these methods of putting out pets to sleep are simply unacceptable.

Clove oil

Clove oil can also be used to sedate shrimp. I do not know shrimp’s tolerance threshold to clove oil, so, I heavily overdose it, just to be sure.

  1. Add 10 drops of clove oil per 25 oz (0.5 liters) of warm water.
  2. Mix the clove oil with water. Shake it up if you have a lid on your jar.
  3. The liquid should become milky-looking.
  4. Put shrimp into this liquid.
  5. Wait until it stops moving. It usually takes a few minutes.
  6. For euthanizing, you need to leave them in the clove oil for 5-10 minutes more.
  7. Or you can put the jar into the freezer, to make sure that shrimp have been successfully put down.

Some other … less humane methods include:

1. Using them as food for bigger fish and turtles

The problem is that snails and shrimp feel the predators around. It stresses them a lot. Of course, they may die very quickly but still … it is not painless and stress-free.

2. Put them in boiling water

I have already mentioned that some countries do not consider boiling crustaceans as a very humane method to kill them. They should be at least knocked out first.

Making them unconscious is the main goal. This way they will not feel any possible pain.

3. Flushing them down the toilet

This is cruel and there is no excuse for that.

4. Squashing them

Some people could never squish shrimp or snails. They do not have the stomach for it. 

However, in my opinion, this is probably the best way if you do not have any other options. In addition, this is the fastest way to put them out of misery.

The main problem though is that people usually do it wrong, as a result, they may even prolong their suffering for a short time.

If you have to do it – place the shrimp between two flat planks and step on them.

Note: DO NOT try to break their spine, chop or decapitate shrimp. Their internal anatomy is different. It will not shut down their nervous system immediately.

5. Immediately freezing them

Ideally, shrimp and snails should be put into the freezer only when they are unconscious and do not feel anything. Putting there alive animals is not really acceptable.

Some people will argue that shrimp and snails are cold-blooded animals. So, it should be completely painless with barely any stress to them.

Well, it is true but only to some degree.

Indeed, their body temperature varies with the temperature of the environment. They do not have control of their heat balance. But there is one thing with the water – once the temperature reaches 39 F (4 C), it expands slightly until it reaches the freezing point. In addition, when water completely freezes it expands by approximately 9%.

In means that shrimp might be still alive when water in their tissues starts increasing in volume thus breaking everything in their body.

Is it painless? I don’t think so.

The good thing though is that a gradual decrease in temperature will slow their metabolism and tropical snails and shrimp will be asleep long before ice crystals form. Therefore, if you use this method, do not drop animals into cold water! They should not feel any temperature shock.

Some people say that none of the methods listed above are humane and could be considered animal cruelty. 
I do agree but only to some degree. Although some of them can be violent, they are also fast and effective.

In Conclusion

How to best euthanize your snails and shrimp in a humane manner so that you can minimize their suffering is something that any aquarists should be aware of.  

The key element here is the rapid induction of unconsciousness with minimal distress and pain. Therefore, beer and clove oil is a low-cost, ready-made, natural, safe, and most important anesthetic tool we can use for our pets.

I know, it is heartbreaking to do it with your own hands. But sometimes it really is the only option.

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