Incidence of pyometra in Swedish insured cats

Pyometra is a clinically relevant problem in intact female cats and dogs. The etiology is similar in both animal species, with the disease caused by bacterial infection of a progesterone-sensitized uterus. Here, we studied pyometra in cats with the aim to describe the incidence and probability of developing pyometra based on age and breed. The data used were reimbursed claims for veterinary care insurance or life insurance claims or both in cats insured in a Swedish insurance database from 1999 to 2006. The mean incidence rate (IR) for pyometra was about 17 cats per 10,000 cat years at risk (CYAR). Cats with pyometra were diagnosed at a median age of 4 years and a significant breed effect was observed. The breed with the highest IR (433 cats per 10,000 CYAR) was the Sphynx, and other breeds with IR over 60 cats per 10,000 CYAR were Siberian cat, Ocicat, Korat, Siamese, Ragdoll, Maine coon, and Bengal. Pyometra was more commonly diagnosed with increasing age, with a marked increase in cats older than 7 years. The mean case fatality rate in all cats was 5.7%, which is slightly higher than corresponding reports in dogs of 3% to 4%. Geographical location (urban or rural) did not affect the risk of developing the disease. The present study provides information of incidence and probability of developing pyometra based on age, breed, and urban or rural geographical location. These data may be useful for designing cat breeding programs in high-risk breeds and for future studies of the genetic background of the disease.     

Differential expression of Toll-like receptor 4 (TLR4) in healthy and infected canine endometrium

This study provides the first report into immunohistochemical localization of Toll-like receptor (TLR) in the canine reproductive tract. TLR4 was investigated in endometrium during the estrous cycle and in pyometra. Pyometra is the most important pathological condition of the uterus due to bacterial infection in dogs. To protect against invading pathogens, the female reproductive tract has evolved immune mechanisms. TLRs are the cellular components of the afferent arm of the innate immune system. The expression of TLR4 was significantly higher in the endometrial stroma compared to the endometrial surface epithelium and glandular epithelium in proestrus. The glandular epithelium and stroma at the diestrous stage expressed TLR4 significantly higher than surface epithelium. Furthermore, when compared to other healthy groups, the glandular epithelium at diestrus also higher expressed TLR4 than other stages. The expression of TLR4 in the surface epithelium was higher in dogs with pyometra compared with all other groups. And, the surface epithelium of dogs suffering from pyometra also expressed TLR4 more intensely than the glandular epithelium. The innate immunity of infected canine endometrium response to bacterial infection is intensely extremely increased by the expression of TLR4. Furthermore, the different levels of TLR4 expression seems related to physiological changes in distinct cell types of endometrium, leukocytes populations, cytokines and sex hormones.     

Concentrations of C-reactive protein,serum amyloid A,and haptoglobin in uterine arterial and peripheral blood in bitches with pyometra

Pyometra is a life-threatening reproductive disorder that affects the uterus of female dogs. This study was designed to identify the possible indicators of uterine inflammation by comparing C-reactive protein (CRP), serum amyloid A (SAA), and haptoglobin (Hp) concentrations in uterine arterial and peripheral venous blood in bitches with open- and closed-cervix pyometra. CRP, SAA, and Hp concentrations were higher in bitches with closed-cervix pyometra irrespective of the site of blood collection. Higher acute-phase protein concentrations were observed in peripheral compared with uterine arterial blood in bitches with closed-cervix pyometra, whereas the levels were comparable in dogs with open-cervix pyometra. Our results indicate that mean acute-phase protein concentrations differ according to pyometra type/severity and blood source and suggest the possible use of peripheral blood levels of CRP, SAA, and Hp to monitor inflammation during the course of pyometra.     

Induction of canine pyometra by inoculation of Escherichia coli into the uterus and its relationship to reproductive features

To characterize oestrus-related factors affecting the induction of and recovery from pyometra in bitches, 60 clinically healthy beagle bitches were used for induction of pyometra by inoculation of Escherichia coli into the uterus during oestrous and metoestrous stages. The animals were classified into the following six groups according to inoculation time: Days 1-10, 11-20, 21-30, 31-40, 41-50 and 51-60 after LH surge. The incidence of pyometra during the periods Days 11-20 and 21-30 after LH surge was 90.9% and 78.9% respectively, while that during Days 1-10 and 51-60 after LH surge was less than 20%, and the patterns of the incidence of pyometra and the serum progesterone levels were similar. There was no difference in the incidence of pyometra induced in bitches less than 5 years old compared to bitches over 6 years old. Oestrus in all of the bitches with pyometra induced by E. coli returned with or without PGF 2alpha treatment, unlike in bitches with spontaneous pyometra. The duration of the oestrous cycle in the non-treated and PGF 2alpha-treated groups was 231.4+/-55.2 days and 162.1+/-40.6 days (P < 0.001), respectively, and there was no difference in the rate of return of oestrus between the two groups. The conception rate in all of the bitches in which oestrus had returned was 81.8%. The above findings indicate that the period during which severe pyometra could be induced was limited to the early stage in metoestrus.     

Blood lactate levels in 31 female dogs with pyometra

Background  

Canine pyometra is a life-threatening disease common in countries where spaying of dogs is not routinely performed. The disease is associated with endotoxemia, sepsis, systemic inflammatory response syndrome (SIRS) and a 3–4% mortality rate. Blood lactate analysis is clinically valuable in predicting prognosis and survival, evaluating tissue perfusion and treatment response in human and veterinary critical care settings. The aims of the present study were to investigate 1) the blood lactate levels of female dogs with pyometra by a hand-held analyser and 2) if these levels are related with the clinical status or other biochemical or hematological disorders.     

Mucometra, cystic endometrial hyperplasia, and pyometra in the bitch: advances in treatment and assessment of future reproductive success

Pyometra is a common reproductive disorder which affects nearly one fourth of all female dogs before they reach 10 y of age. An association between pyometra and the most common uterine disease of the bitch, cystic endometrial hyperplasia, has been established, as the latter allows commensal bacteria originating from the vagina to proliferate in the uterus at the end of estrus. The progressive degenerative process in the development of cystic endometrial hyperplasia is usually proposed as the initiating lesion for pyometra in bitches; this is mediated by progesterone and potentially aggravated by estrogens. However, a separate process caused by local uterine irritation to trophoblastic reaction and bacterial proliferation has been recently proposed as an alternate mechanism leading to the development of pyometra. Pyometra is clinically distinct in pathogenesis, signs, treatment and prognosis from postpartum metritis or mucometra. Treatment of pyometra has historically involved ovariohysterectomy, however, during the last 10 y, numerous effective treatments have been proposed to treat both open and closed cervix pyometra with good success and future fertility. Among the treatments available, the use of repeated low doses of prostaglandins alone or in association with either dopamine agonists or progesterone-receptor antagonists has been demonstrated to be a viable alternative for valuable breeding dogs.     

A breed-matched case-control study of potential risk-factors for canine pyometra

The objective was to evaluate plausible risk-factors for pyometra, a common disease affecting almost 25% of all (unspayed) female dogs before 10 years of age. Because of the strong breed-predilection, an age- and breed-matched case-control study was undertaken on 87 pairs (pyometra-cases and healthy controls) from five breeds (Rottweiler (n = 13), Collie (n = 8), Golden retriever (n = 24), Labrador retriever (n = 16) and German shepherd dog (n = 26)). The mean age was 7.9 y (range 0.8-13.8 y). Variables analyzed included pseudopregnancy, age at first oestrus, length of and regularity of the interoestrus interval, hormone treatments, nulliparity, number of parities, age at first whelping, previous urinary tract infections and mammary tumours. Data were modelled multivariably using matched-pair conditional logistic regression. Analysing interactions with breed, previous pregnancy was statistically associated with pyometra. When amalgamated, in three breeds previous pregnancy was protective (Rottweiler, Collie, Labrador retriever) and in one breed statistically intermediate (German shepherd dog) when compared to the baseline (Golden retriever). Previous pregnancy was a statistically significant factor that had a protective effect against pyometra in some breeds but not in the Golden retriever breed. These findings indicate that protective- and risk-factors may vary between different breeds. The obvious problem with low power and limited possibility for extrapolation, using few dogs in few breeds, is acknowledged. However, it is suggested that failure to control for the confounding effect of breed, especially in epidemiological studies on dog diseases, may lead to potentially erroneous conclusions.     

Epidemiological Study of Mammary Tumors in Female Dogs Diagnosed during the Period 2002-2012: A Growing Animal Health Problem

Epidemiological studies enable us to analyze disease behavior, define risk factors and establish fundamental prognostic criteria, with the purpose of studying different types of diseases. The aim of this study was to determine the epidemiological characteristics of canine mammary tumors diagnosed during the period 2002-2012. The study was based on a retrospective study consisting of 1,917 biopsies of intact dogs that presented mammary gland lesions. Biopsies were sent to the Department of Pathology FMVZ-UNAM diagnostic service. The annual incidence of mammary tumors was 16.8%: 47.7% (benign) and 47.5% (malignant). The highest number of cases was epithelial, followed by mixed tumors. The most commonly diagnosed tumors were tubular adenoma, papillary adenoma, tubular carcinoma, papillary carcinoma, solid carcinoma, complex carcinoma and carcinosarcoma. Pure breeds accounted for 80% of submissions, and the Poodle, Cocker Spaniel and German Shepherd were consistently affected. Adult female dogs (9 to 12 years old) were most frequently involved, followed by 5- to 8-year-old females. Some association between breeds with histological types of malignant tumors was observed, but no association was found between breeds and BN. Mammary tumors in intact dogs had a high incidence. Benign and malignant tumors had similar frequencies, with an increase in malignant tumors in the past four years of the study. Epithelial tumors were more common, and the most affected were old adult females, purebreds and small-sized dogs. Mammary tumors in dogs are an important animal health problem that needs to be solved by improving veterinary oncology services in Mexico.     

Canine pyometra: a study of the urinary proteins by SDS-PAGE and Western blot

Canine pyometra often causes glomerulonephritis by immune complex deposition in the glomeruli. Proteinuria, ranging from moderate to severe, may be present secondary to renal damage. To determine urinary protein excretion due to pyometra, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was conducted on urine from 15 bitches with pyometra and 10 healthy bitches. To characterize urinary immunoglobin excretion, Western blot analysis of the urine samples using antibodies to canine IgG and IgA was also performed. Nine bands were detected by electrophoresis in bitches with pyometra, while only four were detected in the healthy animals. The urinary proteins from bitches with pyometra were primarily of glomerular origin; 58% were of medium-high molecular weight (MW), and the remainder were low MW. None of the healthy dogs had IgG or IgA in their urine, whereas three bitches with pyometra had IgG in their urine and another bitch with pyometra had both IgG and IgA. The low proportion of bitches with urinary immunoglobins was probably be due to early diagnosis of the disease. Although only a limited number of dogs was used, this study is apparently the first to characterize the electrophoretic pattern of urinary proteins and to quantify urinary excretion of IgG and IgA in bitches with pyometra.     

Prevalence of species of Toxocara in dogs, cats and red foxes from the Poznan region, Poland

The prevalence of toxocariasis was evaluated for 445 dogs, 105 cats and 92 foxes from the Poznan region during 1997-1998. Forty one cats were infected (39%), 140 dogs (32%) and 15 red foxes (16%). Toxocara canis was found most frequently in puppies up to 3 months old (58%) and T. cati in kittens 4-6 months old (64%). Toxocariasis was much more prevalent amongst adult foxes (14%) than adult dogs (3%). In contrast to cats, female dogs and foxes were less infected than males. The present study suggests that cats may constitute an underestimated risk of transmission of Toxocara spp. to humans and the progressive synatropization of red foxes may also increase the sources of environmental contamination with Toxocara eggs.     

Exploring mechanisms of sex differences in longevity: lifetime ovary exposure and exceptional longevity in dogs

To move closer to understanding the mechanistic underpinnings of sex differences in human longevity, we studied pet dogs to determine whether lifetime duration of ovary exposure was associated with exceptional longevity. This hypothesis was tested by collecting and analyzing lifetime medical histories, age at death, and cause of death for a cohort of canine ‘centenarians’– exceptionally long‐lived Rottweiler dogs that lived more than 30% longer than average life expectancy for the breed. Sex and lifetime ovary exposure in the oldest‐old Rottweilers (age at death, ≥ 13 years) were compared to a cohort of Rottweilers that had usual longevity (age at death, 8.0–10.8 years). Like women, female dogs were more likely than males to achieve exceptional longevity (OR, 95% CI = 2.0, 1.2–3.3; P = 0.006). However, removal of ovaries during the first 4 years of life erased the female survival advantage. In females, a strong positive association between ovaries and longevity persisted in multivariate analysis that considered other factors, such as height, body weight, and mother with exceptional longevity. A beneficial effect of ovaries on longevity in females could not be attributed to resistance against a particular disease or major cause of death. Our results document in dogs a female sex advantage for achieving exceptional longevity and show that lifetime ovary exposure, a factor not previously evaluated in women, is associated with exceptional longevity. This work introduces a conceptual framework for designing additional studies in pet dogs to define the ovary‐sensitive biological processes that promote healthy human longevity.     

Plasma thyroxine and cortisol under basal conditions and during cold stress in the aging dog

The effects of aging on plasma concentration of thyroxine (T4) and cortisol and on responses of these hormones to low ambient temperatures were determined in the dog. Female beagle dogs were divided into three age groups: old, adult, and puppies. The mean (+/- SD) ages were 11.4 +/- 0.2 years, 3.0 +/- 0.4 years, and 7.6 +/- 0.2 weeks, respectively. All dogs came from a genetically homogeneous colony and were free from any disease. The adult and old dogs were used during anestrus. Based on four daily blood samples, the mean (+/- SE) T4 level in the old dogs (2.8 +/- 0.1 microgram/dl) was significantly (P less than 0.001) lower than that in the adults (4.2 +/- 0.2 micrograms/dl) and puppies (4.4 +/- 0.2 micrograms/dl). By contrast, mean plasma cortisol levels in the old dogs (21.1 +/- 3.1 ng/ml) and adults (15.4 +/- 2.4 ng/ml) were significantly higher than those in the puppies (7.2 +/- 1.1 ng/ml). No significant changes in plasma T4 and cortisol occurred in any of the three age groups at 22 degrees C or during exposure to 10 or 4 degrees C. Exposure to -5 degrees C, however, produced significant increases in T4 (greater than 130% by 5 hr) and cortisol (greater than 280% by 1 hr) in adult dogs. This temperature produced only a modest increase in T4 (70% by 3.5 hr) and no change in cortisol in the old dogs. The puppies showed no change in T4 and cortisol during exposure to -5 degrees C. The results demonstrate that with advancing age, plasma T4 and cortisol concentrations change in opposite directions, thus supporting the hypothesis of a negative relationship between these two hormones. These results also show that the responses of these hormones to the stress of cold decline during aging and are not yet developed in the very young.     

Influence of reproductive status on in vitro oocyte maturation in dogs

In the bitch, oocytes need 48-72 h to complete post-ovulatory maturation to the metaphase II stage in the isthmus of the oviduct, an interval similar to that found in in vitro studies. The effect of estrous cycle stage on in vitro meiotic competence of dog oocytes has been described in several studies. However, there are no reports evaluating the possible effects of pyometra or pregnancy on subsequent potential of oocytes recovered from such females to undergo in vitro maturation.In this study, immature cumulus-oocyte complexes (COCs) were recovered from fresh excised domestic dog ovaries in various reproductive states. The donor females were classified into groups based on stage of the estrous cycle: follicular (proestrus or estrus), luteal (diestrus) or anestrus or at the clinical conditions of pregnancy and pyometra. Grades 1 and 2 oocytes were cultured in vitro at 37 degrees C in TCM-199, supplemented with 25 mM Hepes/l (v/v), and with 10% heat inactived estrous cow serum (ECS), 50 microg/ml gentamicin, 2.2 mg/ml sodium carbonate, 22 microg/ml pyruvic acid, 1.0 microg/ml estradiol, 0.5 microg/ml FSH and 0.03 IU/ml hCG. The nuclear maturation rate was evaluated at 72 h of incubation under Hoechst 33342 (10 microg/ml) staining for fluorescence microscopy. There was no statistical difference in nuclear progression to the MII stage among the various reproductive states (follicular phase, 5.4%; diestrus, 4.2%; anestrus, 4.4%; pyometra, 8.1% and pregnancy, 4.7%). Resumption of meiosis was 24.6% at the follicular phase, 19.6% for diestrus, 16.4% for anestrus, 37.1% for pyometra and 29.2% for pregnancy. Positive and higher numbers of residue above the expected value were observed for the pyometra and pregnancy conditions at the metaphase/anaphase I (MI/AI) stages.Our results indicate that in vitro nuclear maturation of dogs oocytes is not influenced by the in vivo reproductive status of the female. The quality of the oocyte is a more reliable indicator of its potential for meiotic maturation in vitro than the hormonal environment of the donor female at the time of oocyte retrieval.     

Concentrations of cardiac Troponin I before and after ovariohysterectomy in 46 female dogs with pyometra

Background  

Canine pyometra is a common disease in countries where routine spaying of young dogs is not common practice. This disease is known to lead to systemic inflammation potentially affecting multiple organs in the body, including the heart. Cardiac-specific Troponin I (cTnI) is a sensitive marker of myocardial cell damage, which can result from ischemia, trauma, toxins or inflammation. Dogs with pyometra are also exposed to anaesthesia which can potentially result in myocardial cell damage. The aims of the study were 1) to evaluate the occurrence of myocardial cell damage as indicated by increased serum concentrations of cTnI in dogs with pyometra and relate these to presence of systemic inflammation and 2) to evaluate the change in cTnI-concentrations after anaesthesia and surgery.     

Bacterial colonization of the ovarian bursa in dogs with clinically suspected pyometra and in controls

Septic peritonitis occurs relatively commonly in dogs. Secondary septic peritonitis is usually associated with perforation of intestines or infected viscera, such as the uterus in pyometra cases. The aim of this study was to evaluate the bacterial flora in the ovarian bursae of intact bitches as a potential source of contamination. One hundred forty dogs, clinically suspected of pyometra, were prospectively enrolled. The control group consisted of 26 dogs that underwent elective ovariohysterectomies and 18 dogs with mammary gland tumors that were neutered at the time of mastectomy. Bacteriology samples were taken aseptically at the time of surgery from the bursae and the uterus in all dogs. Twenty-two dogs that were clinically suspected of pyometra had sterile uterine content (“mucometra” cases); the remaining 118 had positive uterine cultures (“pyometra” cases) and septic peritoneal fluid was present in 10% of these cases. Of the 118 pyometra cases, 9 had unilateral and 15 had bilateral bacterial colonization of their ovarian bursae. However, the bacteria from the ovarian bursa were similar to those recovered from the uterine pus in only half of the cases. Furthermore, positive bursae were also seen in one mucometra dog (unilateral) and in four control dogs (two unilateral and two bilateral). The data illustrate that the canine ovarian bursa can harbor bacteria. The biological importance of these isolations remains unclear.     

Visceral leishmaniasis in the Metropolitan Region of Belo Horizonte, State of Minas Gerais, Brazil

In the last few years the number of human cases of American visceral leishmaniasis in the Metropolitan Region of Belo Horizonte (MRBH), Minas Gerais, Brazil has increased, indicating an elevation in the transmission rate of the disease. The total number of notified human cases in the MRBH since 1994, when the first case was identified, up to 1999 was 345 of which 223 (65%) were from the city itself, indicating an urbanization of the disease in this region of Minas Gerais. The age distribution of visceral leishmaniasis cases in the MRBH shows a higher prevalence in children from 0-4 years old, responsible for 28.9% of the notifications. Clinical and immunological findings from dogs infected with Leishmania chagasi are described. The majority of these animals showed no sign of the disease. Sera from all infected dogs showed detectable Leishmania-induced high titles of antibodies based on the results of an indirect fluorescent antibody test. Samples of isolated Leishmania from human and dogs were characterized as L. (L.) chagasi by biochemical and molecular techniques.     

阻塞性肺气肿模型的制作

目的在2周内对国际标准实验动物Beagle犬进行肺气肿模型的制作,建立较为标准的肺气肿模型,从而为治疗慢性阻塞性肺疾病（COPD）的方法提供良好的动物模型。方法Beagle犬8只,雌雄各半,2岁,体重13～18kg,雾化吸人木瓜蛋白酶12000U/kg,1次,周,共2周。实验前后测量试验动物肺功能,做胸部CT及病理学比较。结果实验前后动物肺功能,CT及病理学检查均显示较大的差异。8例实验动物的功能残气量（FRC）、肺总量（TLC）、功能残气量比肺总量（FRC/TLC％）、潮气量（VT）和呼吸频率（BR）,在肺气肿模型制作前后做两两比较,结果显示均有统计学差异P〈0.05,血氧饱和度（SpO2）0.05两者间无统计学差异。CT显示肺体积增大,局部肺野透亮度增加有肺大泡形成。试验后病理学检查显示肺泡壁破坏,肺泡间质断裂,肺泡融合,形成典型的全小叶型肺气肿改变。实验后动物出现肺气肿征表现,如气喘,咳嗽及上呼吸道分泌物增等。结论在标准实验动物身上可以较为准确、快速地复制出近似于人类阻塞性肺气肿病理改变的动物模型。     

Dopamine agonists, anti-progestins, anti-androgens, long-term-release GnRH agonists and anti-estrogens in canine reproduction: a review

Over the last 10 years, new drugs have been applied to canine reproduction, widening the spectrum of therapeutic possibilities for diseases that were previously surgically treated, and facilitating better control of the estrous cycle and fertility. Some are not approved for use in dogs; their use is experimental and further clinical trials are necessary. Dopamine agonists such as cabergoline, bromocriptine or metergoline are ergoderivative alkaloids that exert an anti-prolactinergic effect via stimulation of D2 pituitary receptors or inhibition of central serotoninergic ones. Their main indication is suppression of lactation. Anti-prolactinergic compounds have also been successfully used for pregnancy termination and shortening of interestrous intervals. Anti-progestins, (e.g. mifepristone and aglepristone) are synthetic steroids that bind with high affinity to progesterone (P4) receptors, preventing P4 from exerting its biological effects. Anti-progestins have been indicated in P4-dependent conditions, such as pregnancy termination, induction of parturition and the medical treatment of pyometra. Several groups of drugs have been described to have anti-androgenic properties through different mechanisms of action: progestins, receptor binding anti-androgens (e.g. flutamide), competitive enzyme inhibitors (e.g. finasteride), aromatase inhibitors, and GnRH agonists. Their main application is medical treatment of benign prostatic hyperplasia. Long-term release formulations of GnRH agonists (e.g. leuprolide or deslorelin acetate) postponed puberty and reversibly suppressed reproductive function in male and female dogs for periods exceeding 1 year. Anti-estrogens (e.g. clomiphene and tamoxifen citrate) are synthetic non-steroidal type I anti-estrogenic compounds that competitively block estrogen receptors with a combined antagonist-agonistic effect. In dogs, their action is more agonistic than antagonistic.     

Cystic endometrial hyperplasia-pyometra complex in the bitch: should the two entities be disconnected?

The uteri of 26 clinically healthy bitches and 42 bitches with a clinical suspicion of pyometra were examined histologically using a computerized image analysis system. Histologic lesions were characterised mainly by thickening or atrophy of the endometrium and by varying degrees of cystic changes of the glands. These lesions were observed in most of the clinically healthy bitches as well as in all of the clinically ill animals. In most of the ill bitches a variable degree of inflammation also was found. Some bitches with clinical signs indicative for pyometra had no inflammatory reaction in the uterus. These bitches were misdiagnosed as suffering from pyometra, confirming the difficulty of diagnosing pyometra by simple clinical examination. Determination of sex hormone serum levels revealed that all dogs in both groups were either in metestrus or in anestrus. Based on the results of this study the cystic endometrial hyperplasia-pyometra complex can be divided in two entities: a cystic endometrial hyperplasia-mucometra complex and an endometritis-pyometra complex. Both entities bear many similarities with each other, except for the inflammatory reaction in the endometritis-pyometra complex. It is concluded from this study that the latter complex probably does not necessarily follow the former, but that both can arise de novo.     

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

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.