The characteristic pattern of aspartate aminotransferase and alanine aminotransferase in the bitch with the cystic hyperplasia-pyometra complex: effect of medical or surgical treatment

Age-related pregnancy results and further examination of bitches after aglepristone treatment of pyometra

The cystic endometrial hyperplasia and pyometra complex is one of the most common uterine diseases in bitches. The appearance of pharmacological preparations containing anti-progestagens created new possibilities for pyometra treatment. The aim of this study was to evaluate the curative effect of the anti-progestagen aglepristone treatment of pyometra in bitches of different ages. Twenty four bitches of different breeds, aged from 0.8 to 9.5 years (21-48 kg) exhibiting clinical pyometra symptoms (two groups - I < or = 5 years, n = 14 and II >5 years, n = 10) were evaluated. Information about the general reproductive health was collected up to 54 months after anti-progestagen treatment. Remission of clinical symptoms and return of blood chemistry results and total leucocyte count to referential values were achieved in all cases within 14 days of treatment. Bitches were naturally mated at the first, and when unsuccessful, the second oestrus after treatment. In group I, no recurrence of pyometra symptoms was observed during following cycle(s). Eight bitches (57.1%) had a full-term pregnancy and the number of newborn pups ranged from 1 to 12. None of the bitches from the group II became pregnant. In conclusion, the basic indication for conservative pharmacological treatment of pyometra is preserving female fertility and obtaining offspring. The important conditions for successful aglepristone treatment are: the young age (up to 5 years) and the lack of detectible ovarian cysts. It seems necessary to mate bitches in the first or second oestrus after finishing treatment. The efficacy of treatment can be measured by the after-treatment pregnancy rate.

Pyometra in bitches induces elevated plasma endotoxin and prostaglandin F2alpha metabolite levels

Endotoxemia in bitches with pyometra can cause severe systemic effects directly or via the release of inflammatory mediators. Plasma endotoxin concentrations were measured in ten bitches suffering from pyometra with moderately to severely deteriorated general condition, and in nine bitches admitted to surgery for non-infectious reasons. Endotoxin samples were taken on five occasions before, during and after surgery. In addition, urine and uterine bacteriology was performed and hematological, blood biochemical parameters, prostaglandin F2alpha metabolite 15-ketodihydro-PGF2alpha (PG-metabolite), progesterone and oestradiol (E2-17beta) levels were analysed. The results confirm significantly increased plasma levels of endotoxin in bitches with pyometra and support previous reports of endotoxin involvement in the pathogenesis of the disease. Plasma concentrations of PG-metabolite were elevated in pyometra bitches and provide a good indicator of endotoxin release since the concentrations were significantly correlated to the endotoxin levels and many other hematological and chemistry parameters. The gamma-globulin serum protein electrophoresis fraction and analysis of PG-metabolite can be valuable in the diagnosis of endotoxin involvement if a reliable, rapid and cost-effective test for PG-metabolite analysis becomes readily available in the future. Treatment inhibiting prostaglandin biosynthesis and related compounds could be beneficial for bitches suffering from pyometra.

C-reactive Protein in the Differentiation of Pyometra From Cystic Endometrial Hyperplasia/Mucometra in Dogs

Hematological parameters, plasma C-reactive protein (CRP), and tumor necrosis factor αwere analyzed in 64 dogs with a presumptive diagnosis of pyometra. Final diagnosis (i.e., pyometra or cystic endometrial hyperplasia [CEH]) was determined by histopathology. As a single test, the percentage of band neutrophils had the highest sensitivity in the prediction of pyometra (sensitivity, 94%). The combination of percentage of bands and CRP had the highest sensitivity (97.7%; specificity, 75%) in predicting the presence of pyometra. The most common clinical signs noted in the study were vaginal discharge, polyuria, polydipsia, lethargy, and gastrointestinal signs. A combination of three or more of these clinical signs was significantly associated with pyometra.

Vasopressin secretion in response to osmotic stimulation and effects of desmopressin on urinary concentrating capacity in dogs with pyometra

OBJECTIVE

To determine vasopressin (VP) secretory capacity during osmotic stimulation and the response to desmopressin treatment in dogs with pyometra and control dogs.

ANIMALS

6 dogs with pyometra before and after ovariohysterectomy and 6 control dogs.

PROCEDURE

Urine osmolality (Uosm) was measured during 12 hours. Values measured on the first day defined the basal Uosm pattern. On the second day, dogs were given desmopressin to induce a desmopressin-stimulated Uosm pattern. On day 3, the VP response to osmotic stimulation was examined.

RESULTS

Median Uosm on day 1 was 340 mOsm/kg (range, 104 to 1,273 mOsm/kg) and 807 mOsm/kg (range, 362 to 1,688 mOsm/kg) in dogs with pyometra before and after surgery, respectively, and 1,511 mOsm/kg (range, 830 to 1,674 mOsm/kg) in control dogs. Median Uosm during desmopressin treatment was 431 mOsm/kg (range, 168 to 1,491 mOsm/kg) and 1,051 mOsm/kg (range, 489 to 1,051 mOsm/kg) in dogs with pyometra before and after surgery, respectively, and 1,563 mOsm/kg (range, 1,390 to 2,351) in control dogs. In dogs with pyometra, threshold for VP secretion was lower before surgery (median, 340 mOsm/kg; range, 331 to 366 mOsm/kg) than after surgery (median, 358 mOsm/kg; range, 343 to 439 mOsm/kg) or in control dogs (median, 347 mOsm/kg; range, 334 to 360 mOsm/kg). Highest maximum plasma VP values were found in dogs with pyometra.

CONCLUSIONS AND CLINICAL RELEVANCE

Dogs with pyometra had increased urine concentration in response to desmopressin but not to the degree of control dogs, whereas VP secretory ability was not reduced.

Ultrasonography and Cystic Hyperplasia-Pyometra Complex in the Bitch

Cystic endometrial hyperplasia-pyometra complex is the most frequent and important endometrial disorder encountered in bitches. The pathogenesis of the disease is related to the activity of progesterone [Feldman and Nelson, Canine and Feline Endocrinology and Reproduction (1996) W.B. Saunders, Philadelphia]. Cystic endometrial hyperplasia (CEH) is an abnormal response of the bitch's uterus to ovarian hormones [De Bosschere et al. Theriogenology (2001) 55, 1509]. CEH is considered by many authors to be an exaggerated response of the uterus to chronic progestational stimulation during the luteal phase of the oestrous cycle, causing an abnormal accumulation of fluid within the endometrial glands and uterine lumen (De Bosschere et al. 2001). The resulting lesions of pyometra are due to the interaction between bacteria and hormones. The aim of this study was to evaluate if transabdominal uterine ultrasonography can be a useful and reliable diagnostic method to confirm Dow's [Veterinary Record (1958) 70, 1102] and De Bosschere's histopathological classification of CEH-pyometra complex. The study was carried out on 45 bitches with pyometra, 10 purebreds and 35 crossbreeds, 1-15 years old, 20% of which had whelped at least once. None of these animals had received exogenous oestrogen or progesterone treatment. On admission the 45 animals were in the luteal phase of the oestrus cycle. Clinical signs, blood parameters, uterine ultrasonography, bacterial swabs and uterine histopathological results were recorded. Results suggest that ultrasonographic examination is a useful and reliable tool for the diagnosis of cystic endometrial hyperplasia.

Uterine oestrogen and progesterone receptor expression in experimental pyometra in the bitch

Pyometra was induced in five bitches by the intraluminal inoculation of a ligated uterine horn in metoestrus with an Escherichia coli suspension, the other horn serving as an uninoculated control. Histologically, the inoculated horns resembled those with naturally occurring pyometra, while the uninoculated horns had an inactive appearance instead of the normal metoestrus appearance. Immunohistochemically, the expression of sex hormone receptors in the inoculated horns corresponded with that in natural cases of pyometra. In the uninoculated horns, virtually no expression of sex hormone receptors was observed, in contrast to such expression in normal metoestrus. Bacteria-associated ovario-uterine interactions may have been responsible for the hyperplastic (inoculated horn) and inactive (uninoculated horn) uterine changes observed in this experiment.

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.

Bacteriological findings, blood chemistry profile and plasma endotoxin levels in bitches with pyometra or other uterine diseases

Uteri from 60 bitches with a clinical diagnosis of pyometra, or with an enlarged uterus as revealed radiographically or ultrasonographically, underwent histopathological examination, at which a diagnosis of pyometra was established in 48 of the 60 (80%) cases. Escherichia coli was isolated from 43 (90%) of the 48 uteri with pyometra. In 8 of the 60 cases, other pathological uterine conditions, such as endometrial hyperplasia, adenomyosis, mucometra or hydrometra, were diagnosed histopathologically. No bacterial growth was observed in the uteri of these 8 cases. Four of the 60 bitches (6%) showed no pathological changes in the uterus, and in 3 of these no bacteriological growth was seen in the uterus, while in one case a sparse growth of mixed culture was found. Blood samples from bitches with uterine infection caused by gram-negative bacteria showed marked hematological changes. These included higher total WBC counts and a more marked left shift in the differential WBC count than among the other bitches. Toxic degeneration of neutrophils was present among the bitches with gram-negative uterine infection and the serum ALP level was slightly higher than in the other groups of bitches. The plasma endotoxin concentration was determined in 53 bitches before surgery, in 28 bitches after surgery and in 11 control dogs. Only in 7 of the samples was endotoxin detected. The general condition of the bitches included in the present study was only mildly to moderately affected, and in no case indicated severe endotoxemia.