Because, Humans are animals, and it makes sense to think the same about our friends (no matter how venomous or disgusting).Besides, if Animals don't have souls, neither do we. We both can show emotions such as empathy or sadness, no matter how cold of an exterior we have. Besides, when you think about it, we're the same exact thing, other than us arguably being smarter (which we prove, every single day, for the opposite to be true).
I have heard an argument stating that animals do not have souls because they have no sense of morals and because they are not able to reason. However, babies and small children cannot reason either. They also do not know about morals yet. This does not mean that they do not have souls. If babies and small children could have souls despite being oblivious to the concept of God, morals, and the afterlife, then so could animals.
Nobody thought that electricity existed until we found a way to actually see/use it. We all have a soul. Humans, animals, etc... If you want to see for yourself that humans have a soul, but I doubt you will ever have a chance, take a look an human eyes before and after death. When we die our soul leaves the body and the body then becomes only matter, which is why I think that burying is absurd.
We as human beings make theological arguments for our souls but most religions started without any real belief in a soul. Our souls are self evident by the fact that we are aware.
Animals also are aware beings. Awareness is way more than simply being conscious or having language. Although it may be conceivable that the human brain may in fact be processing information based on sensory input and memories this does not lead to being aware.
When you sleep you may have heightened awareness or feel very little awareness because your thinking mind has shut down. But the fact that you can be aware with out thinking or outside of emotions means you are more than your physical brain processing input.
Animals have the same capacity for awareness and pain and joy that we do. Any argument for the human soul is an argument for the animal soul.
All living things human or not, have an existence therefore, have a soul.
Whether or not they can convey what they feel as clearly as humans can, trust they have the emotions and thoughts we do. What else would explain the reactions they have towards different things everyday? Dogs to cats, cats to mice?
Humans don't have souls. Nothing has a soul. Tell me, where exactly might the soul be? Where in the universe is it? I don't believe there is a god. As much as I hate to admit it to myself, I don't think humans or animals have souls. There really isn't any logic to back up the existence of any souls.
I don't think that something as a 'soul' exists. Our consciousness is the result of connected neural cells. Humans are animals as well but the difference between other animals is that our brain is much more distinctive, and so is our mind. I guess other animals have emotional reactions too, maybe they even can "think", but probably those are not as sophisticated as ours.