Build the circut: USB Power + roller switch + wire x4 + buzzer + cloudBit
Run the power cord over the back of the couch or somewhere out of the way, so that it reaches to a convenient crack in the couch cushions.
attach the USB power bit and roller switch and settle them between two couch cushions with the roller switch arm sticking out a bit--just enough so if you set the soccer ball on top, the switch is closed.
Run the wire bits from the switch output around and up the back of the couch with the power cord or to some other out of the way location where the dog won't pull it out.
Set the soccer ball on top of the switch to keep it closed.
Add a recipe on If This Then That: If (cloudBit receives input) then (send email)
Wait for dog to jump on the couch and knock the soccer ball off the switch!