Having just had a meeting with other animal advocacy/justice groups and hearing/feeling the great compassion in the room, I thought i would add here St. Isaac’s teaching on inclusivity, which extends to all of God’s created beings. This is another key component of an Eastern Orthodox position on animal suffering and sooooo much earlier than St Francis:
“And what is a merciful heart…the burning of the heart unto the whole creation, man, fowls and beasts, demons and whatever exists. So that by the recollection and the sight of them the eyes shed tears on account of the force of mercy which moves the heart by great compassion…Then the heart becomes weak and it is not able to bear hearing or examining injury or any insignificant suffering of anything in creation…And therefore, even in behalf of the irrational beings and the enemies of truth and even in behalf of those who do harm to it, at all time he offers prayers with tears that they may be guarded and strengthened: even in behalf of the kinds of reptiles, on account of his great compassion which is poured out in his heart without measure, after the example of God.”
In this teaching, St. Isaac draws us back to the key point of Image of God – mercy, love and compassion “are after the example of God.”To ensure the correct translation, I sought advice from the expert on Syriac studies, Dr. Sebastian Brock who confirms that ‘compassionate’ is the closest to the original Syriac meaning.
 Isaac, Mystic Treaties, Ch. 1, Homily 7.