(Proverbs 14:4 KJV) Where no oxen are, the crib is clean: but much increase is by the strength of the ox.
How are Christians supposed to treat their animals? If you think the Bible is silent, you have not been paying attention. As in most issues we are to be somewhere between the fanatics of PETA and the sadism of a Michael Vick. Animals are not our brothers. They are part of our stewardship.
You can start in creation when Adam was charged with overseeing what God had made. There is at least one other place the issue comes up in Proverbs. Check Proverbs 12:10. As in issues like education, health care, and concern for the poor the contributions of Christians are often ignored and suppressed by modern culture. For instance, William Wilberforce who led the fight against slavery in the British Empire was also involved in the beginning of the SPCA (Society for the Prevention of Cruelty to Animals).
So? We are complete as children of God. The love and compassion that regeneration gives us are exhibited toward all of creation. Don’t think of animals as your children or brothers but they are a part of your responsibility. And it is okay to love them.