Euthanasia -- Putting a Marine Down

[leebca]

It is a sad subject. I'm posting it on its own so that I and others may refer to it should the need arise.

THE NEED?

Pain:
Deciding when to put down your marine fish is not easy. The usual question is, "Is the fish in pain?" Researchers/Scientists are working on that question. From a more or less scientific perspective the fish goes through discomfort first, then stress, then pain as a sequence associated with most animals. So far, it seems that fish suffer significant discomfort stress which we (humans) now believe lead to pain.

I believe evidence will soon emerge which will cast doubt on the fisherman's sport of 'catch-and-release' causing no harm. It seems that information is emerging to indicate a fish feels pain in the fishing sport.

If a fish hook in the mouth is painful, then injuries that can't be treated, broken bones, ripped flesh, etc. is causing pain. A bloated fish from internal infection may be a grey area, but I think it belongs in the pain column. What about what the fish may feel from that bloated eye (Popeye) which many aquarist casually don't treat?

No Cure/No Hope:
If the marine fish has a condition that can't be cured or won't cure and the fish is going to die from the condition, then putting the fish down would be reasonable. Making this decision isn't as straight forward and the aquarist would like it to be. Some thinking has to be done and a decision made. The point where there is little or no hope left is determined by the aquarist. Is the fish 'suffering' from the condition? Is it breathing fast, struggling to swim, unaware of its surroundings?

Best of Two Evils:
Probably the most controversial of all. The number of fishes I have handled over the decades in the hobby has sometimes led to a situation where the decision to put down a fish is based upon the greater good. Certain infections and conditions are so contagious and difficult to cure that I would not allow the fish to enter the QT or hospital treatment system because of the high degree of likelihood the disease will spread to healthy fishes. Such diseases include the bacteria of the Vibrio sp. and the Mycobacterium sp.. It also includes the conditions that appear to be fungal in nature, and yet may not be a true fungal infection.

Fishes are being caught throughout the world and transported for the hobby. To increase survival the collectors and exporters are using antibiotics very carelessly, allowing strains of Vibrio and Mycobacterium to be naturally selected that resist typical antibiotics. Letting such strains into the home aquarium would be devastation, to even healthy fishes. The best thing I can do to protect the healthy livestock is to not let them be contaminated with virulent strains of pathogens that can't be stopped with common antibiotics. Putting the carrier fish down is the best of two evils.

Quality of Life:
I've always appreciated this phrase. If the quality of life for the fish (and aquarist) isn't high, then let the fish slip into the next dimension. An example of this is a fish with a broken spine. It may require hand feeding and special attention and there is no doubt that such fishes are hard to let go, but a totally seriously injured fish fish has a lot of stress heaped upon it. It can't only not compete for its food, but it can't defend itself from other fish that sense its sub standard condition, not worthy of taking up resources needed by the healthy fishes. The fish has other senses, but the aquarist should consider asking, "Is this a good quality of life for that fish?" Whatever happened to make that fish in its condition has caused that fish to die, in my opinion.

Resources v. Results:
I personally don't consider this a reason to put a fish down. But, I realize that there are people who look at the hobby in this perspective. I do not say they are wrong or right. It is just like this for many people. The fish takes on a 'commodity' shroud (turning into an appliance or furniture). Now that commodity is broken.

An inexpensive fish can require up to hundred dollars of medication, equipment, and care very easily. The care includes special equipment, water changes, and time. Medication(s) can be expensive antibiotics that may never be needed again except for this one case.

It is very important to only choose LFS fish for the display tank that are healthy and suitable for captive life, but sometimes this just doesn't happen. The hobbyist either doesn't read these kinds of posts or decides to ignore them for a spontaneous, emotional purchase. See: Is The Fish Healthy?

During quarantine the fish is found to be ill or injured. Can the fish be returned for credit? How much will it cost to help the fish? Will it fully recover or forever be disadvantaged in a community aquarium? Is putting the fish down the best option?


THE DEED

The veterinarian code is simple and straightforward when working with animals: Do no harm. Such is the same code when putting a fish down.

Anesthetics
All veterinarians that often handle fishes, put fish down by an overdose of anesthetic. They use MS-222 (Finquel) which is available in small quantities to the aquarist online. Instructions for different levels of 'sleep' is given on the container. Usually a double dose of the maximum recommended quantity will put the fish into a sleep it won't recover from.

Another choice is the use of Clove Oil (CO). This is more readily available and less expensive. It can be found in health food and vitamin stores (for humans). The fish is caught with as minimal trauma as possible (which isn't too hard since the fish is likely near death) and put into a gallon container with about 2 quarts of tank water. 10-15 drops of CO (or 0.5 to 0.7 ml) is added to 2 cups of tank water in a freezer (thicker) plastic bag. Shake like the dickens (e.g., Charles). The CO doesn't totally dissolve, but it dissipates (breaks up like an oil) and some goes into solution. Add the shaken mixed 2 cups to the two quarts of tank water in the gallon container with the fish.

The CO procedure can be performed without even moving the fish. If the fish is alone in a quarantine tank (QT) and has been going through a quarantine process, the fish can be euthanized while still in the QT. Just use the above ratio and perform the same process.

The fish slowly goes to sleep in less than 4 minutes. When breathing stops (the gill plate stops moving), wait another 15 minutes before disposing of the fish. Another 15 drops of CO can be added to another 2 cups of tank water and shaken, then added to the gallon container if the fish is not going to sleep fast enough.

Other Methods:
A large number of people are under the impression that freezing the fish is humane. It isn't. What happens first is that the fish can't properly take in oxygen. We might liken that to suffocation. As the temperature drops, the gills begin to freeze up (we might liken that to our lungs freezing). So as the fish gasps for air it cannot get, it dies in a cold, dark place. This is definitely not humane. Maybe the aquarist thinks it is okay, but it isn't, based upon when we know about fish. Freezing a fish is one of the most inhumane ways of putting down a fish. I think it became popular because the hobbyists, cowards some tend to be, would just rather pop the fish into the freezer and not have to look at the fish anymore. What they don't see is the suffering, suffocating fish in pain, taking up to 15 minutes to die as its gills freeze over and internal organs freeze and rupture.

Another group believes that a blow to the head will suffice. The fish is taken out of the water and then quickly struck. No matter how fast this is done, the fish is gasping for air, being taken out of the water. This is not humane. Even though the blow to the head is relatively quick, the fish may be struggling in the net (or on the table/floor) and, while waiting even a few seconds for the blow, the fish is aware it is out of water and the fish panics, while the suffocation process starts.

Be the fish. If you had to be killed, how would you like it to happen? Freezing, blow to the head (bludgeoned to death), put into a blender/garbage disposal, cut off your head, or going to sleep?


SUMMARY

There is no doubt that captive wild marine fishes can and do live longer in captivity than in the wild. Unfortunately there are many opportunities for the system to cause harm to the fish that the aquarist cannot repair or correct. There are also conditions the well-meaning aquarist can't correct but which caused harm to the fish, or threatens the healthy fishes in the system. These fish may have been done an injustice, but it may not be in the fish's best interest to prolong its life.

Not an easy decision and not an easy task to perform. The aquarist needs to consider what is best for all concerned. No one can tell the aquarist when to give up on the fish, nor when to allow the fish to pass with dignity. There are no fish rights or laws to provide guidance on what is still often an emotional decision. But what we/I can say is how to do it in a humane manner. Buy a small bottle of clove oil from your health food store.

[weez1959]

"Be the fish. If you had to be killed, how would you like it happen? Freezing, blow to the head, put into a blender/garbage disposal, cut off your head, or going to sleep?"

Well this post really gets you thinking! Even though I haven't had a fatality since I can't remember when, I'm off to the health food store tomorrow for clove oil, you never know when you'll need it
Excellent post Lee!

[Reefland]

Louise, isn't it about time for some updated pictures from you?

[reefbeginner]

I had wondered about this. Thanks for the info as always.