There are many prayers and practices that we can do to help animals and insects, whether they are pets or not. All need liberating from the lower realms. Lama Zopa Rinpoche recommends some main mantras particularly for animals, such as the mantras of Maitreya, Mitrugpa, Chenrezig, Medicine Buddha, Milarepa, Padmasambhava and the other 10 Powerful Mantras. There are a number of FPMT resources that have these mantras and more and are available through the FPMT Foundation Store (www.fpmt.org).
If you are looking for information on How to Hold an Animal Blessing Event, follow this link.
For ideas on how to help animals around you, read the online article in Mandala Magazine ‘Three Ways to Help Animals‘.