Urinary behavior of female domestic dogs ( Canis familiaris): influence of reproductive status, location, and age

Abstract

The urinary behavior of adult domestic dogs ( Canis familiaris) is sexually dimorphic with respect to the posture (males lift a leg and females squat), frequency of urination (males urinate more frequently than females), and tendency to direct urine at specific objects in the environment (males are more likely than females to direct their urine). Such behavioral differences have led to the belief that urination functions largely, or exclusively, in elimination in female dogs, while having the additional function of scent marking in male dogs. In this study, we observed urinary behavior of six spayed and six non-estrous intact female Jack Russell Terriers during walks on and off their home area. The females ranged in age from 0.4 to 11.2 years. Frequency of urination was positively correlated with age, and females four or more years old directed the majority of their urinations at objects in the environment. Overall, females urinated more frequently and directed more of their urinations when walked off their home area than when walked within their home area. Spayed females were more likely than non-estrous intact females to ground-scratch following defecation; we detected a similar trend for ground-scratching after urination. There was, however, considerable variation among spayed females in the tendency to display ground-scratching behavior. Overall, the most common posture displayed by females while urinating was the squat-raise. Other postures, in order of their frequency of occurrence included squat, arch-raise, combination, and handstand. Females used the squat-raise and arch-raise postures more when off their home area than when on their home area. Overall, there was substantial individual variation among females in the postures used while urinating. Our data indicate that female urinary behavior varies with location and reproductive status, and that substantial individual differences exist among females for some patterns of behavior. Additionally, the large percentages of directed urinations by spayed (60.8%) and non-estrous intact females (56.7%) in our study suggest that urination in female dogs does not function solely in elimination, but that it also has a significant role in scent marking, even when females are not in estrus.