Immunosuppression in bitches with pyometra

Emphysematous pyometra and emphysematous hepatitis caused by Klebsiella pneumoniae infection in a diabetic dog

A 14-year-old intact female diabetic dog presented with seizures and hyperglycemic hyperosmolar syndrome. Radiographs revealed gas-filled tubular structures in the right and left caudal abdomen, raising concerns of emphysematous pyometra or small intestinal ileus. Ultrasonography played a pivotal role in confirming emphysematous pyometra, a technique previously documented only once in veterinary practice. This report also presents the first documented case of emphysematous pyometra in a diabetic dog attributed to Klebsiella pneumoniae and complicated by emphysematous hepatitis.

The assessment of haematologic and serum chemistry parameters in canine pyometra: a systematic review and meta-analysis

OBJECTIVES

Pyometra is common in non-spayed adult female dogs requiring early diagnosis and treatment to increase the survival rate. The diagnosis of pyometra is mainly based on clinical examination and anamnesis. Radiography, ultrasonography and laboratory analyses are recommended to support a diagnosis. The aim of this study was to assess blood parameters associated with pyometra by performing a systematic review and meta-analysis.

MATERIALS AND METHODS

The review was conducted in accordance with PRISMA guidelines. A search of three databases (PubMed, Google Scholar and CAB abstracts) was performed in July 2022. Studies providing information about laboratory parameters for both the pyometra group and healthy control group dogs were eligible for inclusion. Data extraction included the first author's name, publication year, country, number of participants in both groups, mean values of selected studies, standard deviation values, and blood parameters. The risk of bias for each study was evaluated, and a random-effects meta-analysis was performed.

RESULTS

We included 44 studies which investigated 12 blood parameters. High heterogeneity was detected in all parameters in these meta-analyses. The following blood parameters were increased in dogs with pyometra: white blood cell (mean=27.75×109  L-1 , mean difference (MD)=17.16, 95% confidence interval (CI) 14.85 to 19.47), monocytes (mean=2.06×1012 /L, MD=1.37, 95% CI 0.99 to 1.74), blood urea nitrogen (mean=41.42 mg/dL MD=18.06, 95% CI 12.26 to 23.85), alkaline phosphatase (mean=212.78 IU/L, MD=137.51, 95% CI 81.81 to 88.62), and aspartate aminotransferase (mean=48.31 IU/L, MD=16.96, 95% CI 10.61 to 23.30). The following parameters were reduced: red blood cell (mean=5.42 1012 /L, MD=-1.37, 95% CI -1.68 to -1.05), haemoglobin (mean=121.20 g/L, MD=-30.57, 95% CI -39.70 to 21.45), albumin (mean=23.71 g/L, MD = -8.16, 95% CI -11.46 to -4.86). Lymphocyte, creatinine, urea, and alanine transaminase parameters were increased in some studies and decreased in others.

CLINICAL SIGNIFICANCE

In canine pyometra, some blood parameters are consistently increased, some consistently decreased, and some increased or decreased depending on the study.

Retrospective evaluation of the use of quick Sepsis-related Organ Failure Assessment (qSOFA) as predictor of mortality and length of hospitalization in dogs with pyometra (2013-2019): 52 cases

OBJECTIVE

To evaluate the prognostic utility of quick Sepsis-related Organ Failure Assessment (qSOFA) for prediction of in-hospital mortality and length of hospitalization in dogs with pyometra.

DESIGN

Retrospective cohort study from February 2013 to April 2019 SETTING: Tertiary referral hospital ANIMALS: Fifty-two dogs referred with confirmed diagnosis of pyometra INTERVENTIONS: None MEASUREMENTS AND PRINCIPAL OUTCOMES: Sixty-five percent of dogs survived to discharge. A cut-off score of ≥2 for qSOFA was associated with in-hospital mortality (odds ratio 6.51 [95% CI: 1.35 - 31.3]) P = 0.019. The area under the receiver operator characteristic curve for a qSOFA score ≥ 2 for mortality was 0.72 (95% CI: 0.59-0.85), with a sensitivity of 77.8% and a specificity of 66.7%. The mean ± SD number of organs with dysfunction was significantly higher in dogs with a qSOFA score ≥2 1.76 ± 0.83 compared to dogs with a qSOFA score < 2 1.08 ± 1.09, P = 0.015. The presence of a qSOFA score ≥ 2 was associated with a longer time of hospitalization in survivors with a median (interquartile range) length of stay in qSOFA < 2 (48 [33]) hours versus qSOFA score ≥ 2 (78 [52]) hours, P = 0.027.

CONCLUSIONS

In dogs with pyometra, the qSOFA score was associated with mortality and length of hospitalization. This score might be useful to improve the risk stratification in dogs with pyometra. Further studies are necessary to evaluate the predictive capacity of qSOFA in other septic patient populations.

Activity of the glycosidases β-galactosidase, α-l-fucosidase, β-N-acetyl-hexosaminidase, and sialidase in uterine tissues from female dogs in diestrus with and without pyometra

This study aimed to compare the activity of selected glycosidases (β-galactosidase, α-l-fucosidase, β-N-acetyl-hexosaminidase, and sialidase) in homogenates of uterine tissues obtained from female dogs with and without pyometra. In addition, it examined the availability of substrates for these glycosidases in the homogenates. The study was carried out on female dogs undergoing ovariohysterectomy for pyometra (n = 10) and clinically healthy dogs (n = 10) undergoing elective spaying. The activity of β-galactosidase, α-l-fucosidase, and β-N-acetyl-hexosaminidase was analyzed using a spectrofluorometer and that of sialidase using a colorimetric method. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis with Alcian Blue (AB) and Periodic Acid-Schiff (PAS) staining was performed to determine the presence of substrates for these glycosidases in the homogenates of uterine tissues. The results revealed that the activity of all the examined glycosidases was significantly higher (P < 0.05) in the uterine tissues isolated from dogs with pyometra in comparison to healthy dogs. The electrophoretic patterns of the selected samples showed several proteins, which contained different sugar moieties stained by AB and PAS and the profiles differed significantly between the pyometra group and the healthy group. Densitometric analysis of AB staining showed patterns between 233 and 148, 86 and 55, and 43 and 20 kDa, which differed markedly in sugar content between the examined groups of animals. Similarly, PAS staining analysis revealed patterns of different molecular weights, between 233 and 117 and between 55 and 32 kDa, which also differed in sugar content. These findings suggest that canine pyometra is accompanied by the increase in the activity of selected glycosidases in the uterus. This could potentially modify the glycan structures of uterine glycoproteins and in result their biological functions. Further studies are needed to elucidate the potential role of the increased activity of glycosidases in the pathogenesis of this disease.

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.

Outcome of pyometra in female dogs and predictors of peritonitis and prolonged postoperative hospitalization in surgically treated cases

BACKGROUND

One of the most common diseases in intact bitches is pyometra--a potentially life-threatening disease associated with a variety of clinical and laboratory findings. The aims of the present study were to describe complications of the disease and to investigate clinically useful indicators associated with peritonitis and/or prolonged postoperative hospitalization.

RESULTS

A retrospective study was performed using records from 356 bitches diagnosed with pyometra during the years 2006-2007 at the University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden. Of the 356 bitches, 315 were surgically treated by ovariohysterectomy, 9 were medically treated and 32 were euthanized without treatment. In the surgically treated bitches, univariable associations between clinical and laboratory data, risk for prolonged hospitalization (≥ 3 days) and/or signs of peritonitis, were analyzed by Chi-square and Fisher's exact test. Logistic regression models were used to assess multivariable associations.The most common complication observed in surgically treated bitches was peritonitis (40 bitches), followed by urinary tract infection (19 bitches), wound infection (8 bitches), uveitis (6 bitches), and cardiac arrhythmia (5 bitches). Leucopenia and fever/hypothermia were associated with increased risk for peritonitis (18-fold and three-fold, respectively). Moderate to severe depression of the general condition, pale mucous membranes and leucopenia were associated with increased risk (seven-fold, three-fold, and over three-point-five-fold, respectively) for prolonged postoperative hospitalization.

CONCLUSIONS

Several clinically useful indicators were identified. Leucopenia was the most important marker, associated with 18-fold increased risk for peritonitis and an over three-point-five increased risk for prolonged hospitalization. Fever/hypothermia, depression and pale mucous membranes were associated with increased risk for peritonitis and/or prolonged hospitalization. The results of the present study may be valuable for identifying peritonitis and predicting increased morbidity in surgically treated bitches with pyometra.

γδ T lymphocytes are recruited into the inflamed uterus of bitches suffering from pyometra

Very little is known about the occurrence of immune system cells in the canine uterus. The aim of this study was to generate information about lymphocyte subsets that are present in the healthy canine uterus and that are recruited under inflammatory conditions caused by pyometra. Using immunohistochemistry and flow cytometry, a significant influx of γδ T lymphocytes was found in pyometra samples mainly due to recruitment of γδ(+)/CD8(-) T lymphocytes. The relative expression of genes encoding selected cytokines/chemokines was evaluated in samples from healthy and pyometra-affected uteri. Expression of pro-inflammatory cytokines (including IL-1β, TNF-α, IL-8, IL-17 and IFN-γ) and chemokines (including CXCL10, CCL4 and CCL5) was upregulated in pyometra samples confirming the presence of inflammation. In contrast, the expression of the homeostatic chemokine CCL25 and of the anti-inflammatory cytokine IL-10 was downregulated and unchanged, respectively.

Mummified papyraceous fetuses in the abdominal cavity of an elderly female dog with pyometra

This paper reports on a rare case of fetal papyraceous mummification after asymptomatic uterine rupture in an elderly female dog with pyometra. The patient had a history of mating six months before the examination but no apparent signs of gestation or parturition. Exploratory laparotomy was used to identify a rupture of the left uterine horn and the presence of cystic endometrial hyperplasia and pyometra. Two mummified papyraceous fetuses were observed in the abdominal cavity and had adhered to the spleen, pancreas, intestine and omentum. Ovariehysterectomy and corrective surgery were performed. The patient had remained healthy after uterine rupture until a new estrous cycle and the development of pyometra. Bitches that are 10 years old or more are predisposed to implantation failure, pregnancy or parturition problems and they should not be breed to avoid complications.

Bacterial and fungal colonisation of peripheral intravenous catheters in dogs and cats

OBJECTIVES

The purposes of this study were to determine the prevalence of intravenous catheter colonisation in a routine clinical setting, to identify pathogens involved and to explore factors associated with an increased risk of colonisation.

METHODS

A prospective study of 100 peripherally placed intravenous catheters from 13 cats and 78 dogs was conducted. The distal two-thirds were removed and submitted for bacterial and fungal cultures. Antimicrobial susceptibility of each isolate was determined.

RESULTS

Nineteen peripheral catheters were positive for microbiologic culture from 14 animals. Twenty organisms were isolated among which Staphylococcus species was the most common. Isolates displayed lower levels of resistance against the antimicrobial agents amoxicillin-clavulanate, cephalosporins and gentamicin than against other agents tested. Major risk factors predisposing to catheter-related colonisation included dextrose infusion, duration of catheter placement, local complications and immunosuppressive diseases or drugs.

CLINICAL SIGNIFICANCE

In a routine clinical setting, the prevalence of microbial colonisation of peripheral intravenous catheters is comparable to that found in an intensive care unit. However, consequences on morbidity and mortality rates differ.

Lactoferrin in canine sera: a pyometra study

The concentration of lactoferrin was measured in canine sera from groups of healthy male dogs as well as pregnant and non-pregnant female dogs and was compared with that of bitches with pyometra. Lactoferrin concentrations were higher in bitches with pyometra. The role of elevated lactoferrin concentrations in the suppression of lymphocyte activity was examined in sera from bitches with pyometra in a series of investigations. Although the sera from bitches with pyometra were capable of suppressing lymphocyte activity, lactoferrin was not found to be involved in this action.

Hysterectomy leads to fast improvement of haematological and immunological parameters in bitches with pyometra

OBJECTIVES

To investigate whether a combination of hysterectomy and antibiotic treatment leads to an improvement of altered haematological and immunological parameters in bitches affected by pyometra.

METHODS

Blood samples obtained from 13 bitches affected by pyometra were investigated before hysterectomy and seven days later for a total and differential leucocyte count, activity of neutrophils and lymphocytes, and quantification of total serum immunoglobulins, lysozyme and circulating immune complexes.

RESULTS

The parameters most affected included changes in blood profile (leucocytosis because of neutrophilia or leucopenia) and inhibition of lymphocyte activity. Seven days after hysterectomy, all affected parameters returned to normal levels comparable to clinically healthy dogs.

CLINICAL SIGNIFICANCE

Application of immunostimulating therapy is not necessary to manage changes in blood cell counts and suppression of lymphocyte activity in bitches with pyometra. Removal of the infected uterus, being the source of infection, leads to improvement.

Lymphatic organ development in dogs: major lymphocyte subsets and activity

In the present study, we have characterized lymphocyte subsets and activity in peripheral blood, spleen, mesenteric and popliteal lymph nodes in pups from birth till the age of one month and compared the results with the situation in the group of three adult dogs. In neonatal pups, lower numbers of CD3(+) T-cells were detected in both the spleen and peripheral blood than in lymph nodes. In contrast to the other compartments, CD21(+) B-cells prevailed in the spleen, which resulted in low values (<1) of the CD3(+)/CD21(+) ratio. Low numbers of CD8(+) lymphocytes were characteristic in all compartments immediately after birth; consequently a high CD4(+)/CD8(+) ratio has been calculated. Postnatal development was characterized by an increasing frequency of CD8(+) lymphocytes in all organs studied. Another typical feature of the early period of life was a relative decrease of B-cell numbers, which was compensated by an increasing proportion of T-lymphocytes, particularly in the peripheral blood and spleen. DNA synthesis in newborn pups' cells as measured by in vitro thymidine incorporation was surprisingly high in non-stimulated control samples, notably in the spleen. Further development of lymphocyte activity was characterized by the decline in spontaneous activity in all organs. Stimulation indices upon mitogen-induced proliferation increased proportionally to the decrease in spontaneous activity. Based on our experimental data, we have concluded that pups are born with a relatively competent immune system the structure of which, however, markedly develops during a few postnatal weeks.

Pyometra in a bitch following unusual sterilisation

A female, stray crossbreed dog, approximately four years old, was presented for routine spaying during a charity neutering programme in Romania. On clinical examination the bitch was lethargic and pyrexic (40.6 degrees C), but no other signs of illness were detected. Laparotomy revealed an enlarged uterus, severed at the cervix, with no communication to the vagina. Abdominal inspection showed an apparently normal, ligated vaginal stump. An ovariohysterectomy was performed and the dog was treated with a seven-day course of netilmicine. It subsequently made a full recovery.

Effect of ovarian hormones on periodical changes in immune resistance associated with estrous cycle in the beagle bitch

In bitches, the onset of pyometra, an infection of the uterus, characteristically occurs in the first half of the diestrous stage in the estrous cycle, in which the blood concentration of progesterone peaks and that of estradiol-17beta is lowest. To investigate the immunological mechanisms governing stage-specific onset of pyometra, peripheral blood mononuclear cells (PBMNCs) were collected from beagle bitches during different stages of the estrous cycle and examined using various immunological assays. When we examined the proliferative response of PBMNCs to PYO-252, that is a clone of Escherichia coli isolated from the uterus of a dog afflicted with pyometra, the response of PBMNCs significantly decreased in the first half (day 10) of diestrus, but increased in proestrus/estrus. No significant differences were observed in the responses to concanavaline A between stages of the cycle. Throughout the estrous cycle, canine PBMNCs did not respond to lipopolysaccharide derived from E. coli. The response of PBMNCs collected in anestrus to PYO-252 was significantly enhanced upon the addition of estradiol-17beta to the culture. In contrast, these responses were significantly suppressed in the presence of progesterone. Progesterone progenitor or metabolite molecules, which have a low affinity for the progesterone receptor, did not affect proliferative responses. Expression of gamma interferon (IFNgamma) in response to PYO-252 was also significantly enhanced by estradiol-17beta, but suppressed by progesterone. This evidence suggests that in the first half of the diestrous stage, suppressed activity of cellular immunity results from increasing progesterone concentration and minimal estrogen release. This marked decrease of immune resistance allows the expansion of E. coli, which enter the uterine cavity through the loosened cervical canal during estrus, leading to pyometra onset.