The Buddha considered animals to be inferior to humans in that they do not have the mental capacity to comprehend the Dhamma and that they have only a rudimentary moral sense. Under monastic law murder is an offence entailing explosion from the Saïgha, while killing an animal has a much less drastic punishment (Vin.IV,124). But this does not mean that the welfare of animals is unimportant. On the contrary, animals' inferior status in such ways makes them extra worthy of our sympathy and protection. They are as libel to pain as we are. The Jàtakamàla highlights both these points when it says; 'Because animals are dull by nature we should therefore have sympathy for them. When it comes to desiring happiness and wishing to avoid pain, all beings are the same. Therefore, if you find something unpleasant you should not inflict it on others.'

... The first requirement in the Buddhist code of moral discipline, the Five Precepts, is to abstain from killing, to lay aside the stick and the sword and to live with care, kindness and compassion for all living creatures' (D.I,4). Anyone who wants to be a wayfarer on the Noble Eightfold Path is askednot to kill, encourage others to kill or approve of killing' (A.V,306). The Buddhacarita says: `Empathy with all creatures is the true religion' (sarveùu bhåteùu dayà hi dharmaþ). For the Buddha love and compassion are incomplete if they do not extended to all sentient beings.

... Despite animals' inferiority to humans the Buddha was prepared to acknowledge that in some ways they can sometimes set an example that humans could do well to copy. Once when some monks were quarrelling with each other the Buddha said to them: 'If animals can be courteous, deferential and polite towards each other, so should you be.' (Vin.II,162)

... Most religions say that we should love other humans. Buddhism broadens and universalizes love by saying that it should be felt for and expressed to all beings, however humble. The earliest legislation to protect animals from cruelty and to provide reserves for wild animals was drawn up by the Buddhist monarch Asoka in the 2nd century BCE. http://www.buddhisma2z.com/content.php?id=22