The animals are blessed with the recitation of the Avalokiteshvara Sadhana and many auspicious mantras during the  puja.

By blessing the animals, participants generate positive intention in their mind and further to the minds of the animals, increasing the likelihood of a future rebirth where they too can engage in spiritual practice and ultimately purify and perfect their minds.   

By saving beings one directly benefits them by giving them precious life and those who save beings also receive immeasurable benefits by creating the positive karma to enjoy a longer life and to be free from illness.  Moreover, this practice is a common and vital practice for those who are sick or have heavy obstacles to their life.