Created in the Image of God

The discussion that we had in class on Monday about what constitutes a person got me thinking about both animal and human euthanasia. It was mentioned in class that persons include beings such as cats dogs, and other sentient beings and that the title is not merely designated for Homo sapiens. It was then discussed later that it is wrong to inflict harm or end the life of another person. I then brought the subject of euthanizing terminally ill pets in class and asked why it was ok to end their life but not the life of a terminally ill human. Since that class I have come up with some general ideas why.
One of the main reasons that I think there is a double standard between the two different types of person is the fact that human lives are valued more than the life of an animal. A majority of people seem to think a human life is worth more than an animal life, whether or not that is right or wrong is another question altogether. When a dog is diagnosed with cancer and is obvious pain and discomfort, many will choose to end their suffering, put them out of their misery, or some other cliché however, when a human is just as ill and is terminal as well the best we can do is to grant them a Do Not Resuscitate order (DNR). They will not put the person out of their misery or they would be subject to a murder investigation.
Another reason that I think that people are leery about ending the life of a terminally ill patient has to do with the fact that religion still has a strong presence in our everyday lives. We are, after all, created in the image of God, how can we put such a creation to death merely because they are suffering and going to die? The bible tells those who chose to read it that we are a divine creation, made by god in his likeness, it is not hard to see why people would think that this makes them special, that it puts them on a pedestal of other lesser persons such as animals. The idea of euthanizing people who are deemed too ill or frail to live also conjures up an image of Nazi Germany and the horrors that so called undesirable people suffered at the hands of Hitler and his regime.
The final reason that I have come up with is the population as a whole is afraid of where to draw the line and who should and should not be allowed to have a physician to end their life. Can only people with illness that will kill them within six months, a year, or just a few days be allowed to choose this option? What do we do with people who are unable to choose for themselves, do we allow family members to chose, what if there is a conflict within the family members over the proper course of action? Should the person be terminal and have chronic and debilitating pain or do they just have to be terminal, and that begs that question over whether or not people who have chronic pain and severe illnesses that are not terminal such as sickle cell anemia be allowed to end their life? Then we have to worry about who decides whose life is worth living, should people with severe mental retardation be euthanized? What about people who are suicidal? I think that a lot of people have these fears and questions about how far this could go if euthanasia was legalized, the whole process becomes a very slippery slope.

Question: Do you think that someone who is terminal ill and in constant pain be allowed to choose to have a doctor euthanize them? Should their family be allowed to choose for them?