The almost unbearably adorable Ludovine, a two and a half year old bloodhound from Alabama (and described by her owner as "really lazy"), was let outside to "do her business" but she wandered-off and and found herself at the start of a half-marathon, whereupon she get caught up in the excitement of it all and joined in.  Apparently she could have come first if she hadn't stopped several times to sniff interesting things.

http://thechive.com/2016/01/26/bloodhound-goes-out-to-use-the-bathroom-ends-up-placing-7th-in-a-marathon-7-photos-video/