There's a common assumption that dog waste "breaks down naturally." It's not. It's the opposite of fertilizer — it's an active health hazard.
What's actually in there
A single gram contains around 23 million fecal coliform bacteria. On top of that:
Why our climate doesn't help
The Inland Empire's mix of hot days and irrigated lawns is actually near-ideal for some parasites.
What pickup prevents
Proper, prompt pickup interrupts the parasite lifecycle. Most parasites need a few days outside the host to become infectious.