It's usually done by administering a massive dose of injected anaesthetic. the dog feels nothing, and simply 'goes to sleep' - hence the term 'putting a dog to sleep'.
Leave it to a cet
check with local law
There is no such process. Just out of curiosity, why?
No, the gas used in veterinary medicine for euthanasia is carbon dioxide. However, because this method is technically difficult and can cause some anxiety in larger dogs, it is not used to euthanize dogs.
Euthanasia
I don't believe their can be a "head" of euthanasia, but Dr. Kevorkian is a well known supporter of the currently illegal process.
Euthanasia is something that is used when an animal is very ill and its quality of life would be very poor. Euthanasia is a good thing when it is used that way.
Euthanasia is not a condition or symptom. Euthanasia is the process by which sodium pentatol or some form of similar drug is injected into the bloodstream in very large doses, so as to purposely cause the death of the individual. This is what Veterinarians do to pets when they are being "put down" humanely. It is also the process used to humanely execute prisoners on death row in some states. Hope this helps. It was hard to tell what you meant by your question, as I think you are confused by the term "euthanasia" and what it pertains to. I supposed one would prevent euthanasia by not overdosing on medications they have been prescribed. Always take medications as directed by your doctor. never self medicate.
Euthanasia is used mainly in animals, and it is a humane way of killing them to stop them suffering.
By any method if they present a threat of serious harm or by euthanasia by a vet
This will depend upon the size, breed and health status of the dog as well as the geographic location you are in. Larger dogs require more euthanasia solution, and dogs that are frantic with pain or panic require sedation for the euthanasia solution to be administered properly.
Euthanasia (from Greek for 'good death') tries to give a humane death. But I believe that unless a cat is ill or suffering, with no hope, cats and dogs should have the same right to live and not be killed.