Yes, it’s true, your dog (or cat) can kill your treadmill. Treadmills are notorious for collecting dirt, dust, and pet hair into the motor compartment (among other things). The picture shown here is one of my client’s treadmills that I recently serviced. I’m surprised it did not short out, or worse, start a fire. It’s happened before. What happened with this one was the power switch shorting out. This is one reason why you should have your treadmill serviced regularly. Also, if it does get serviced by someone other than myself, make sure they take the motor cover off. I was told today by another client she had previous techs come out and not one of them took off the motor cover and told her she needed new parts. I was floored.  She knows they didn’t take it off because she watched them, like she did me, diagnose her treadmill. Anyway to get back to the pet hair, it’s a major problem if you have pets, or have had pets while owning your treadmill. As mentioned, it can short out the motor controller, cause a fire, cause interference with the speed sensor, and cause issues with the rollers. Pet hair isn’t the only thing I’ve found in the motor compartment that causes problems. That may be a topic for another post down the road. 😉