Dogs are territorial by nature and nothing says, “I’m here,” like marking a tree, fire hydrant or fence post with their unique scents. For male dogs, and even some females, urinating is an easy way to spread this scent. The smell communicates all sorts of information to canine passersby, from the gender of the dog that marked to whether that dog was stressed, healthy or in heat. This is not surprising given canines’ powerful noses, but still doesn’t answer the question: Why do some dogs lift their legs to pee?
 
Several theories attempt to explain why Fido raises his leg while he marks. One posits that a dog lifts his leg because this allows him to spread his urine higher, where other dogs are more likely to smell it and where the breeze can more easily spread the scent. Marking higher may also preserve a dog’s scent for longer since other dogs are less likely to reach the same level and “overmark” your pet’s handiwork. This explains why some small dogs become acrobatic experts, balancing on their front feet to mark as high as their larger peers. Likewise, researchers have found that dogs lower on the pecking order tend to sniff, but not pee over, another dog’s mark. Other theories posit that lifting his leg is simply a practical behavior your pet uses to help him avoid a messy encounter. Though many male dogs lift their legs while marking, there’s no need to worry if your pet doesn’t. Most males pick up the behavior between six months and one year old through watching older dogs, but some never develop the habit. This is especially true for puppies that were not raised with older males around or dogs that have been neutered. Likewise, while many female dogs squat to do their business, some urinate with a raised leg, too. Every canine has his or her own preference and your pet’s unique habits should be no cause for concern. If, however, your dog suddenly changes his leg-lifting behavior, this could be a sign something’s wrong. Sudden changes in behavior can indicate an underlying medical condition, such as arthritis or urinary incontinence, is causing your pet discomfort. If you notice a shift in Fido’s favored peeing position, take him to the vet for blood work to identify the problem, if one exists.