Complex sentence: However, as the number of greyhounds successfully transitioning from tracks to households has risen, many people have come to believe that greyhounds are gentle and affectionate dogs who adapt easily to household life because they are clean animals who require moderate exercise.
Split into simpler sentences: However, as the number of greyhounds successfully transitioning from tracks to households has risen, many people have come to believe that greyhounds are good pets. They describe Greyhounds as gentle and affectionate dogs who adapt easily to household life because they are clean and require only moderate exercise.