Many people act as if those working for better conditions for animals care nothing for humans. I find the opposite to be true if you really look. This may be the mindset of some folks, but it is unfair to make a blanket generalization. As Christians, this is particularly important as we are called to be compassionate as Christ was.
"And He said to them, "Go into the world and preach the gospel to all creation." (Mark 16:15)
The Greek word for creation, ktisis, relates to all creation! Taking The Great Commission in combination with several other passages relating to God’s concern for, and salvation of, His creation leads us to the Christian’s obligation to actively care about and for animals. Remember, all creation is known as "General" or "Natural" Revelation; that is, God’s visible proof of His act as Creator (Romans 1:20). Following The Great Commission by sharing the Gospel with all people as well as caring for animals can be uniquely done in a joint effort. "