You only offer two options - for you to replace the plug on your own or to trash the treadmill. An alternative might be to ask someone to put a new plug on for you... It may be that you will need to replace the plug and the cord if the dog has damaged both.
If this becomes a habit for your dog begin preparing to say goodbye to the animal - electrocution is just a doggy chew away...
Changing a plug should be a school-leaving condition.
Good luck...
Peccavi
September 2009
Your dog chewed the cable to your treadmill ! Instead of repairing the cable, sell the treadmill and buy a dog leash with the money, then you can take the dog out for a walk in the fresh air, that way you both get exercise and your dog won't get bored enough to chew through something else.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix gym/fitness equipment.