When you do the Medicine Buddha practice for an animal or person who is sick or dying, visualize the seven Medicine Buddhas (Renowned Glory of Excellent Signs; King of Melodious Sound, Brilliant Radiance of Ability; King of Immaculate Excellent Gold, Radiant Jewel Who Fulfills All His Vows; King of Supreme Glory Who Frees from All Suffering; Melodious Ocean of Proclaimed Dharma; King of Clear Light, He Who Totally Delights in Supreme Wisdom of the Ocean of Dharma; Medicine Guru, King of Lapis Light) one on top of the other, above the animal or person. First visualize that nectars are emitted from the first Buddha and purify the being of all their negative karmas and obscurations. Recite the name of each Medicine Buddha seven times, then allow it to absorb into the each Medicine Buddha in turn.
With the final Medicine Buddha, recite however many mantras you wish and again visualize strong purification. Think that the animal or person has been completely purified; no negative karma at all exists in their mental continuum, and their body becomes as calm and clear as crystal.
The Medicine Buddha then melts into light, absorbs within the animal or person, and blesses their body, speech, and mind so that they become one with the Medicine Buddha. Their mind is transformed into Medicine Buddhas holy mind. Meditate strongly on that oneness.
You can think that the beams are also emitted to all other sentient beings, especially those who are sick with cancer, AIDS, and other diseases, and purify them. Or you can visualize the seven Medicine Buddhas above the crown of each sentient being and purify them in that way. Focus particularly on the person you are praying for, but think that there are also seven Medicine Buddhas above the crown of every other sentient being.
Also, if the person is dying, visualize that a tube-like beam is emitted from Medicine Buddhas heart and becomes a channel inside the person. The channel is shaped like an umbrella handle, hollow inside but with no hole at the end, and extends to just below the navel. Red beams shaped like a hook are sent from Medicine Buddhas heart and hook the persons consciousness, which is visualized the size of a mustard seed, but in the nature of white light. It is not concrete or heavy, but is extremely light. The red hook-like beams hooked the consciousness, and it flies up through the channel to Medicine Buddhas heart. After being absorbed into Medicine Buddhas heart, the consciousness emerges from the heart to take place in a lotus in the pure realm of Medicine Buddha. The person then receives teachings from or predictions about their enlightenment from the Medicine Buddha.
If you have strong compassion and stable concentration during this meditation, you might help to prevent the person being born in the lower realms.