http://www.themodernreligion.com/misc/an/an2.htm#cruelty

The Prophet(s) told his companions of a woman who would be sent to Hell for having locked up a cat; not feeding it, nor even releasing it so that it could feed herself." Narrated by Abdullah bin 'Omar. Bukhari, 4:337.

The Prophet(s) was asked if acts of charity even to the animals were rewarded by God. He replied: 'yes, there is a reward for acts of charity to every beast alive.' (Narrated by Abu Huraira, Bukhari, 3:322.

The Prophet(s) told his companions of a serf who was blessed by Allah for saving the life of a dog by giving it water to drink and quenching its thirst. (Narrated by Abu Huraira. Muslim, Vol. 4, Hadith No. 2244.

Maybe he will be ashamed of himself if you show a greater respect for Islam than he is.