Dr. Nicholas Dodman
Urine marking by leg lifting is a typical canine male behavior by which a dog marks his territory. Most owners are not surprised or alarmed if their male dog lifts his leg on a few bushes, fence posts and fire hydrants outside. They understand that it is normal for a dog to do this. For intact dogs (males or females) the solution is neutering. Approximately 60 percent of "altered" male dogs will cease urine marking within weeks or months of castration. Estrus-related urine marking will be abolished in virtually all females once they are spayed.
Some dogs have an obsession about marking their territory. After all, it is their heritage as pack members to live within a well-delineated territory. A territory contains all the commodities necessary to sustain the pack, including various valuable resources, including their mates and their progeny. Making it clear to strangers that they have crossed a line with respect to territory helps avoid unnecessary fighting.
Dogs use more than simply the odor of urine to define their territory. There are visible clues as well, including marks made on the ground by pawing and scratching. Dogs may also deposit feces strategically to delineate territorial boundaries, These signals, like handwriting, remain long after the sender has gone, providing a reminder to itinerants that they are now entering a restricted area.
Male urine contains pheromones that are derivatives of a male hormone, testosterone, plus other unique markers. These natural chemicals can be detected by members of the same species and will direct them to alter their behavior. The signal sent is akin to "trespassers will be prosecuted."
You may have noticed that male dogs, on reaching a previously urine-marked landmark, will often attempt to cover over the urine marks of previous canine visitors with their own urine. In so doing, they sometimes engage in some quite amusing acrobatics, including the reverse handstand sometimes displayed by little dogs when attempting to over-mark lofty scent marks left by larger dogs.
When male dogs are neutered, leg lifting and the acrobatic displays come to an end in about 60 percent of dogs. Dogs that still mark territory after the surgery may be just acting out hard-to-break habits.
Some females urine-mark, too, though less frequently than males. This is understandable since no behavior is unique to either sex. Some behaviors, though, so-called "sexually dimorphic behaviors," are displayed more commonly by one sex. This is the case with leg lifting which is, more typically, a male behavior. But some perhaps dominant females, or those that have been raised in predominantly male litters, also acquire the habit.
Females do produce small quantities of testosterone, so there will be some small quantities of testosterone breakdown products in their urine. But they also excrete their own urinary (and vaginal) pheromone, parahydroxybenzoic acid (PHBA), which signals their estrus status and receptivity to mating. This signaling is (appropriately) strongest during a heat cycle. Most females do not leg lift, but they frequently deposit urine to advertise pending sexual receptivity. Urine marking by intact females is performed more frequently from the squatting posture. Spayed females usually cease urine marking, though the occasional spayed female will urine mark when stressed.
If urine marking by leg lifting or squatting in females is conducted exclusively outside, it is not usually a problem for the owner and is certainly not one for the dog. The real problem occurs when urine marking is happening inside the home. This can be a real source of annoyance for the owner though, again, it is not a problem for the dog. As natural as leg lifting and other forms of urine marking may be, it's still not acceptable to owners to have such signaling directed toward their sofa or best wingback armchair.
Neutered males may start urine marking if they are territorially stressed or frustrated. External stresses for dogs include unwelcome visits from neighborhood dogs, especially female dogs in heat. Keeping strange dogs away is of course a logical option.
Dogs are also more likely to urine-mark if they have an exaggerate view of their own importance within the household. When a dog is strutting his stuff without due respect for his owners, a dominance control program is warranted.
Some dogs that leg lift, or otherwise urinate inappropriately around the house, are driven to do so because of prevailing anxiety or stress. A typical scenario is that a dog discovers that his territory has been invaded by a new baby or unwelcome house-guest. The anxiety created by such a situation may cause dogs to signal their disapproval by means of urine marking. In these latter cases, more complicated behavior modification programs, involving acclimation and desensitization of the dog to the offending parties, can be instrumental in correcting the problem.
In all cases of in-home urine marking, it is imperative to effectively clean up the odors of previous urine marks by using biological odor neutralizers. Attempting to mask the urine with various scents is almost universally ineffective. It is imperative to use an enzymatic or bacterial product that will destroy the behavior modifying odors at the source. Some trade names of appropriate products are Anti-Icky Poo® (AIP), Nil-Odor®, Odornil®, OdorBan®, Nature's Miracle®, etc.
In rare instances when neutering, dominance control programs, anxiety-reducing measures, and thorough clean up are ineffective, pharmacological intervention may be the last resort. The type of drug usually used for this treatment is with an anti-depressant, typically an older style tricyclic anti-depressant. Amitriptyline (Elavil®) and imipramine (Tofranil®) have both been used with good success. These drugs seem to work by stabilizing the dog's mood, increasing his confidence, plus toning the bladder sphincter. Where anxiety is thought to be involved, the anxiety-reducing drug, buspirone (BuSpar®), may prove effective. Appropriate desensitizing measures should be applied simultaneously.