There's a problem.
The Hiawatha trail is privately operated, and you have to pay to use it. They may have had “issues” with dogs in the past (more likely with the dog owners). Plus, it has some long, dark tunnels which may have been a contributing factor.
Dogs are allowed on the CDA trail, and it’s assumed that the owners are responsible for biohazard removal.
1.7 mile long pitch-black tunnel and several bridges hundreds of feet high might have something to do with it...