[metta2uall]

I love how this sutta makes it clear what its definition of pure love is (wishing that everyone is well, unconditionally), and that this should be cultivated towards all beings, including animals.

Sadly though most Buddhist laypeople are not vegan, though some popular teachers like Thich Nhat Hanh did promote minimising the suffering of animals via such practical means as making vegan choices..

Regarding meditation, Ajahn Brahm from the Thai Forest Tradition has taught extensively not just focused Metta Meditation, but how Metta (i.e. love/acceptance) towards the present moment is a key part of other techniques like meditation of breathing. One of his books, "Kindfulness", really gets into this.