This is a complex issue that touches on multiple concerns in a variety of fields.
Euthanasia of animals is legal for a number of reasons: animals are considered property under the law (equivalent to a TV or car); animals have not historically be afforded the same 'right to life' that humans have been; animals can result in significant financial burdens that are difficult to pass to a social safety net.
Deliberately causing the death of a human being, however, is considered to be a moral sin by most religious traditions (except in the case of self-defense or war). This argument is based on the concept that God gave all humans life so only God should be the one to take those lives away. Humans are also generally recognized as having a basic intrinsic 'right to life' that cannot be superceded by the wishes of another human being.
There are some groups that feel that humans should have the right to request assistance in ending their own lives; this is usually referred to as "assisted suicide", "physician-assisted suicide" or some variation thereof rather than euthanasia. The primary argument put forth by these groups is that humans have the right to decide what happens to their bodies while they are living but are contradictorially being denied the right to decide when they will exit that body.
Animals do not have the same legal rights as humans.
In the United States, most euthanasia procedures are for animals and are performed by veterinarians. However, in Oregon physician-assisted suicide (a form of euthanasia) is legal under strict medical oversight, and the death penalty (state-sponsored involuntary euthanasia) is legal throughout the United States.
The most important reason is fear; fear that euthanasia can so easily be abused.
there are not any religions that enflight on euthanasia being legal
Euthanasia is illegal in China. While there have been discussions on end-of-life decisions and legislation around palliative care, euthanasia remains prohibited by law in China.
No, euthanasia is illegal in Greece.
no
No
At this time, only Oregon and Washington have legal (and unchallenged) euthanasia laws.
euthanasia is legal in the Netherlands with or without the consent of the patient. Guidelines have been adopted to allow the killing of newborns. Euthanasia is legal in Belgium and Luxembourg
Euthenasia is not legal period.
Botched euthanasia is a spinal disorder in most animals that makes it hard for animals to walk.