The Buddha is in Each Sentient Being in Chinese / Japanese...

佛は衆生の中に在り is “Butsu wa shujo no naka ni ari” and means that the Buddha (potential for Buddhahood) exists in all beings in the universe.

So yes, your dog has the potential to be a Buddha (but only in a future reincarnation as a human). But all things, from the tiny cricket to the humpback whale have Buddha nature within them. If one takes the time to look and contemplate, one will see the Buddha in all things.

In Japan, sometimes the Buddha character is written 仏 instead of 佛, so you might see the whole phrase written as 仏は衆生の中に在り.

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.

佛心 means the Buddha's mind, Buddha-heart, or the spiritually enlightened heart/mind.

The Buddha Heart is detached from good and evil and other such constructs. The Buddha Heart has mercy, compassion, and loving-kindness for all sentient life, the good, the wicked, and all in between.

The heart and mind (心) are the same concepts in the ancient Orient, so you can use heart and mind interchangeably in this context.

見性成佛 is a universal phrase that suggests that one may see one's nature and accomplish Buddhahood.

見性 suggests penetrating deep inside oneself to see one's “Original finally Mind.”

成佛 refers to a sentient being who dispenses with illusions and delusions through ascetic practice, is enlightened to the truth, and becomes a Buddha.

This is used by Mahayana, Chan, and Zen Buddhists in China, Korea, and Japan.

You will also see this with the last character written as 仏 in Japanese. In the religious context, 佛 is commonly used to mean Buddha. If you want the other version, see Kenshō Jōbutsu 見性成仏