Monday, November 11, 2013

Why Do Dogs Mark Territory with Urine?

Dogs pee for two reasons: to piddle or send a message.  Considering that more than a million and a half gallons of urine are deposited daily in the US by roughly 57 million dogs, that’s a lot of information. 
Sending a message 
Odor, like e-mail, moves over great distances, remains in place long after the sender is gone, and hangs around until the sendee picks it up.  

Picking up her p-mail message

Urgent, special delivery, confidential, registered, return to sender?  How do dogs ever sort it out?  University of Colorado biologist Marc Bekoff found a novel way to “see” how dogs respond to odor, by examining yellow snow.

Professor Marc Bekoff and his assistant, Jethro

Scent-marking is differentiated from merely urinating by a number of criteria that include sniffing before urinating, or directing the urine stream at urine that's already. 

During five consecutive winters in snowy Boulder, Colorado, Professor Bekoff moved nearly 400 clumps of fresh, yellow urine-saturated snow from place to place to see how his dog, Jethro, would react to his own urine and that of other dogs.  (How people reacted to the Professor isn’t mentioned.)

The science behind yellow snow
Bekoff shoveled snow that was stained with his dog’s urine and moved it to various posts to see if Jethro would cover his own scent with urine. The professor noted that Jethro created a map, urinating regularly at specfic posts.  Jethro was least interested in his own urine, and spent most of his time investigating the urine of other males compared to females.  The dog clearly discriminated his own odiferous messages from those of others. 

Read the study: 
Bekoff, Marc, Observations of scent-marking and discriminating self from others by a domestic dog (Canis familiaris): Tales of displaced yellow snow, Behavioral Processes, 55 (2001) 75-79.
Scratch and sniff
A new study, published November 11, 2013 indicates that bacteria in the scent gland may be the key to information in the message.  


  1. I find this particular behaviour fascinating as I take my two female dogs out for their walks!! They both have different styles or marking/peeing and only one scratches the ground after she is done!!!!! It's definitely a secret world of smells for them as they read the 'doggy newspaper' among the grass stalks and shrubbery while out of their own patch of ground!!!!!

  2. Mine was a marker, he left his scent on the outer perimeter of our yard. Every morning he was make the rounds, sniff each area for new scent and then remark over it with his.