Leonardo is up for adoption at Tony La Russa's Animal Rescue Foundation in Walnut Creek. The 108-pound mastiff was tied with a cord and locked in a bathroom in a Central Valley home for several weeks. He was left with a kitten and chihuahua for company.
Animal rescuers think all three formed a bond and survived their ordeal by drinking toilet water.
"When he first came in he was so malnourished that he couldn't have his vaccinations until he went through," said Animal Rescue Foundation Executive Director Elena Bicker.
The animals were abandoned when the owners moved to Las Vegas.
Neighbors called Animal Control after noticing the driveway had sat empty.
Other chihuahuas being kept in two crates perished because they had no water.