Pyometra in Small Animals 2.0

Canine Euthanasia's Trend Analysis during Thirty Years (1990-2020) in Italy: A Veterinary Hospital as Case Study

This study aimed to investigate changes in the number of, and reasons for, requests for dogs' euthanasia over the last thirty years. Data (breed, age, gender, neuter status, manner, and cause of death) from dogs' euthanasia registered between 1990 and 2020 in a small animals' veterinary hospital were analyzed. The overall period examined has been split into two terms (T1 = 1990-2004 and T2 = 2005-2020) considering the introduction and enforcement of Law 189/2004. During the whole period examined, a significant increasing trend in euthanasia cases has been recorded (p = 0.027). Comparing the two terms, we observed significant differences regarding variables such as age, breed, reproductive status, and ownership. The number of euthanized dogs was significantly higher in T1 than in T2. Dogs euthanized in T2 were older than dogs in T1. A high percentage of the euthanized dogs were crossbred and stray dogs. Additionally, the number of neutered/spayed dogs was significantly higher. Regarding the cause of death, a significantly higher percentage of neoplastic processes was detected in T2. The data here reported suggest a potential influence of Law 189/2004. This law in Italy has proven to be a legal milestone that has influenced the decision-making process between euthanasia and natural death.

The Canine Vaginal Flora: A Large-Cohort Retrospective Study

Microbiological examinations are frequently performed as part of breeding management examinations in the bitch, but also in case of (suspected) reproductive tract problems. As most bacteria are opportunistic pathogens, evaluation of bacterial findings is challenging for veterinarians. Besides, breeders might request antimicrobial treatment in breeding bitches, fearing conception failure-even without medical indication. Considering the rising threat of antimicrobial resistance, gaining deeper insights into the bacterial findings from the vagina of healthy and (suspected) reproductive-diseased bitches might contribute to the knowledge of the canine aerobic vaginal flora and consequently improve the responsible use of antibiotics. We analyzed results from bacteriological cultures of 23,254 vaginal swabs sent in to three commercial laboratories in Germany between 2015 and 2021, where standard aerobic microbiological examination was carried out. We found a variety of 319 bacterial species that mostly grew in mixed cultures of two or more bacterial species. Commonly found species were Escherichia coli, beta-hemolytic Streptococci, coagulase-positive Staphylococci, Pasteurellales, and aerobic sporulators, as well as other Streptococcus spp. Our results showed a large diversity of the canine vaginal flora in healthy and (suspected) reproductive-diseased bitches. They largely support earlier findings of small studies on the physiological canine vaginal flora, emphasizing that solely the results of a bacterial evaluation should not be the base for antimicrobial treatment. Instead, bacterial findings should be evaluated with the results of a clinical gynecological examination.

Association between bacterial pathogenicity, endometrial histological changes and clinical prognosis in canine pyometra

Despite the high frequency and clinical relevance of canine pyometra, its pathogenesis remains poorly understood. In this study, the clinical data, histopathological alterations, and microbiological findings of 39 dogs with pyometra were analyzed to assess possible associations. The mean age of the affected animals was 9.6 ± 3.8 years; 76.3 % (29/38) had open cervix pyometra, 88 % (22/25) had tachypnea, 71 % (27/38) had anorexia, and 60.5 % (23/38) had leukocytosis. Histopathological analysis revealed that 66.5 % (26/39) of the uteri had a high degree of inflammation (score 4). Third-degree hyperplasia of the endometrial epithelium (72 %, 28/39) and intralesional or intrauterine bacteria (66.5 %, 26/39) were identified in most animals. Bacterial isolates were obtained from 82 % (32/39) of the uterine contents and five bacterial species were identified. Escherichia coli, classified in phylogroup B2, is associated with virulent adhesion genes (fimH, focG, and papC), and serum resistance (traT) was the most common isolate. There was an association between the detection of papC in E. coli isolates and higher necrosis scores. Additionally, the necrosis score was positively associated with the length of hospitalization, with each point increase in the necrosis score leading to two more days of hospitalization. These results suggest that papC-positive E. coli play an important role in the severity of pyometra in dogs. The present study revealed the possibility of using this virulence gene to better understand the prognosis of the disease in an affected animal.

Canine Pyometra: A Short Review of Current Advances

Pyometra, characterized by the accumulation of purulent exudate in the uterus, is the most prevalent reproductive disease in canines. While the disease often begins with mild local symptoms, it can escalate into peritonitis, sepsis, and multi-organ dysfunction, thereby posing a significant threat to life. Despite the high incidence and recognized significance of canine pyometra, gaps persist in our understanding of its epidemiology, etiology, and pathogenesis. Recent studies have, however, broadened our comprehension of this disease, shedding light on potential new infection sources, etiologies, and the application of clinical predictive biomarkers and new therapeutic protocols. This study aimed to review the current understanding of canine pyometra, with particular emphasis on the latest research concerning its etiology and epidemiology. Furthermore, it addressed key research questions and proposed directions for future investigations into various facets of canine pyometra.

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.

Comparison of the efficacy of altrenogest versus transdermal progestin patches on estrus synchronization and ovulation in mares

Background and Aim

The adhesive progestin patch was investigated for estrus synchronization in mares because this method is convenient and safe in other species. This study aimed to compare the efficacy of a transdermal progestin patch versus oral altrenogest on estrus synchronization, preovulatory follicle development, and ovulation.

Materials and Methods

Twenty-four broodmares were randomly divided into two groups. In Group 1, mares (n = 12) were fed 0.044 mg/kg altrenogest daily for 14 days. Group 2 (n = 12) mares were treated with adhesive transdermal progestin patches for 14 days. Mares were observed for estrus daily, from day 3 until day 7, after hormone withdrawal. Follicular development was determined by ultrasonography. The preovulatory follicle size and ovulation time after hormone treatments and ovulation rate were determined for both groups. Plasma progesterone levels were measured during the experimental periods and 2 days after hormone termination in both groups.

Results

The results revealed that the transdermal progestin patch efficiently controlled follicular growth and estrus synchronization in mares. The percentage of mares exhibiting estrus was similar in the altrenogest (100.00%) and transdermal patch (91.67%) groups. Ovulation rates were equivalent with either altrenogest or progestin patch protocols (91.67% [11/12] vs. 83.33% [10/12]). In addition, the preovulatory follicle size was similar in mares treated with altrenogest and progestin patches.

Conclusion

This study revealed that the transdermal progestin patch provides effective estrus synchronization and ovulation, similar to altrenogest treatment. However, the transdermal patch was more convenient with a shorter predictable ovulation time after estrus synchronization and should be considered as an alternative method for mares.

Antimicrobial use in the surgical treatment of canine pyometra: A questionnaire survey of Arizona-licensed veterinarians

BACKGROUND

Recent studies and consensus statements in veterinary and human medicine recommend more judicious use of antimicrobials. While guidelines have been provided for some veterinary diseases, others have poorly elucidated guidelines. Postoperative treatment of canine pyometra is a condition with minimal guidelines regarding antimicrobial use.

OBJECTIVE

To identify and investigate patterns of antimicrobial use following surgically treated canine pyometra.

METHODS

A 23-question survey, sent to 863 small and mixed animal practitioners, investigated demographics, patterns of antibiotic use, rate of culture submission and participant's recollection of outcomes of surgically treated pyometra cases. Responses were analysed for relationships between demographics, patterns of antibiotic use and culture results to better understand reasoning for antibiotic protocols.

RESULTS

One hundred and fifty-two responses were received. Overall, 76% of veterinarians stated they always use preoperative and perioperative antibiotics, and 74% stated they always use postoperative antibiotics. A total of 16 different antibiotics were reported. Twelve per cent of respondents regularly submitted a culture. Culture submission was impacted by cost, prior experience, poor owner compliance, result turnaround time and anticipated results.

CONCLUSIONS

Most respondents always used antibiotics and rarely or never submitted a culture. To optimise patient care, future clinical studies are needed to determine specific guidelines for the use of culture and antibiotics in the treatment of canine pyometra following ovariohysterectomy.

Postoperative complications and antibiotic use in dogs with pyometra: a retrospective review of 140 cases (2019)

BACKGROUND

Pyometra is commonly seen in intact bitches and is usually treated by ovariohysterectomy. Few studies have reported the frequency of postoperative complications, particularly beyond the immediate postoperative period. Swedish national antibiotic prescription guideline provides suggestions about which antibiotics should be used and when in individuals undergoing surgery. Studies on how well clinicians adhere to these guidelines, and on the outcome for these patients, have not been evaluated for cases of canine pyometra. This retrospective study conducted at a private Swedish companion animal hospital assessed complications that developed within 30 days of pyometra surgery, and whether clinicians followed the current national guidelines in regard to antibiotic use. We also assessed whether antibiotic use affected the rate of postoperative complications seen in this cohort of dogs, where antibiotics were predominantly used in cases presenting with a more severely depressed general demeanour.

RESULTS

The final analysis included 140 cases, 27 of which developed complications. In total, 50 dogs were treated with antibiotics before or during surgery and in 90 cases, antibiotics were either not given at all or treatment was initiated postoperatively (9/90) due to a perceived risk of infection developing. Superficial surgical site infection was the most common complication, followed by an adverse reaction to the suture material. Three dogs died or were euthanised during the immediate postoperative period. Clinicians adhered to national antibiotic prescription guidelines on when antibiotics should be given in 90% of cases. SSI only developed in dogs that were not given pre- or intra-operative antibiotics, while suture reactions did not appear to be affected by antibiotic use. Ampicillin/ amoxicillin was used in 44/50 cases given antibiotics before or during surgery, including most cases showing signs of concurrent peritonitis.

CONCLUSION

Serious complications following the surgical treatment of pyometra were uncommon. Excellent adherence to national prescription guidelines was observed (90% of cases). SSI was relatively common and only seen in dogs that were not given antibiotics before or during surgery (10/90). Ampicillin/ amoxicillin was an effective first choice antimicrobial in cases requiring antibiotic treatment. Further studies are needed to identify cases benefiting from antibiotic treatment, as well as the duration of treatment needed to reduce the infection rate while also avoiding unnecessary preventive treatment.

Treatment of a Recurrent Pyometra by Surgical Uterine Drainage in a Main Coon Cat

Pyometra is a uterine disease typical of the luteal phase of the estrus cycle. For selected patients, such as breeding subjects, ovariohysterectomy is not a valid resolutive option. Medical treatments involving cloprostenol and aglepristone have been developed for the cats, but they can be ineffective in rare cases. Transcervical drainage and flushing have been described for the dogs, as well as for large wild cats. However, to the author's knowledge, there are no report of uterine drainage in cats. The present case describes an alternative treatment of pyometra in a 3-year-old Main Coon previously treated with aglepristone. The patient underwent a laparotomy: the uterus was exposed, and a sterile urinary catheter was inserted into each horn, through the wall of the uterus, to allow the drainage of pathological collection and a subsequent lavage with lukewarm sterile saline. Medical treatment with aglepristone and marbofloxacin was associated. After treatment, no recurrence was reported, and the cat had an uneventful pregnancy. Although it is a unique case report, the results presented are promising, as the technique appears to have provided healing and preserved fertility. Further studies are needed to confirm its efficacy in the long-term prevention of recurrence.

A study on the correlation between intrauterine microbiota and uterine pyogenesis in dogs

Pyometra is a common and high-incidence reproductive system disease in female dogs, and its development involves both hormonal and bacterial factors. Characterization of the endometrial microbiome in healthy dogs and diseased dogs with pyometra remains unclear at present, however. In this study, dogs with pyometra were identified based on the clinical examinations, hematology examinations, vaginal smears and uterine histopathology. The endometrial samples of healthy dogs (n = 30) and diseased dogs (n = 41) were then collected and sequenced by 16S rRNA high-throughput sequencing technology. Dogs with pyometra suffered from inflammation, and their endometrial microbial diversity (ACE and Chao 1 indices) was significantly lower than that of healthy dogs (P < 0.05). The endometrial samples of both groups were enriched in four phyla (Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria), with a greater abundance of Firmicutes in diseased dogs (P < 0.05). At the genus level, the most prevalent microbes in diseased dogs belonged to Pseudomonas, Escherichia-Shigella, Mycoplasma, Enterococcus, Haemophilus, Vibrio and Ralstonia, with lower levels of Mycoplasma, Enterococcus and Haemophilus in the healthy control. Principal co-ordinates analysis and non-metric multi-dimensional scaling showed that the endometrial microbiome of diseased dogs clustered separately from that of the healthy controls (P < 0.05). In the LDA effect size analysis, 18 members of the endometrial microbiome were screened. Of these, the bacterial species Pseudomonas_aeruginosa and microbes within the genera Mycoplasma, Enterococcus and Haemophilus were found to be enriched in the uteruses of diseased dogs. Furthermore, the Random Forests model further confirmed that Mycoplasma and Haemophilus could be considered as biomarkers of diseased endometrium. In conclusion, this study provided a theoretical basis for the development of probiotic preparation in the future.

Transmission of Escherichia coli Causing Pyometra between Two Female Dogs

Despite its clinical relevance, the pathogenesis of canine pyometra remains poorly understood. To date, it is recognized as a non-transmissible infectious disease. In this study, the simultaneous occurrence of pyometra and Escherichia coli in two cohabitant female dogs underwent in-depth investigation due to the hypothesis of transmission between these animals. Two 5-year-old Chow Chow dogs (namely, dogs 23 and 24-D23 and D24) were referred to a veterinary hospital with suspected pyometra. Both animals showed prostration, anorexia, and purulent vulvar discharge over a 1-week period. After ovariohysterectomy, uterine tissue, uterine contents, and rectal swabs were collected for histopathological and microbiological analysis. Uterine histology demonstrated purulent material and multifocal necrosis with endometrial ulceration, and a morphological diagnosis of pyometra was confirmed. Furthermore, E. coli from the same phylogroup (B2) and positive for the same virulence factors with the same antimicrobial susceptibility profile was isolated from the uterine contents of both dogs and the rectum of D23. Conversely, the E. coli strains recovered from D24 differed in phylogroup (one isolate), virulence factors (all three isolates), and antimicrobial susceptibility (all three isolates). Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) suggested that all isolates from the uterine content of both dogs and the rectal swab of D23 were 100% the same, but different from all isolates in the rectal swab of D24. One isolate from the uterine content of each animal as well as rectal swabs were subjected to whole-genome sequencing (WGS). Both whole-genome multilocus sequence typing(wgMLST) and single-nucleotide polymorphism (SNP) analysis supported the hypothesis that the isolates from the uterine content of both animals and the rectal swab of D23 were clonal. Taken together, these clinical features, pathology, microbiology, and molecular findings suggest, to the best of our knowledge, the first transmission of E. coli associated with pyometra between two animals. These results could impact the management of sites where several females cohabit in the same local area such as kennels.

MicroRNA Expression Variation in Female Dog (Canis familiaris) Reproductive Organs with Age and Presence of Uteropathy

While aging is associated with microRNA (miRNA) expression, little is known about its role in the aging of dog reproductive organs. We examined miRNA expression in ovaries, oviducts, and uteri from young and old dogs and dogs with uteropathy to elucidate miRNA's role in aging. The ovaries, oviducts, and uteri of 18 dogs (Canis familiaris)-young (8.5 ± 1.9 months old), old (78.2 ± 29.0 months old), and those with uteropathy (104.4 ± 15.1 months old)-were collected for miRNA expression examination. Total RNA samples were extracted, reverse-transcribed to cDNA, and real-time PCR analysis was also performed. In ovaries, miR-708 and miR-151 levels were significantly higher in old dogs than in young dogs, and only let-7a, let-7b, let-7c, miR125b, and miR26a were significantly upregulated in dogs with uteropathy. In the oviducts and uteri of old dogs, miR-140, miR-30d, miR-23a, miR-10a, miR-125a, miR-221, and miR-29a were upregulated. Realtime quantitative PCR revealed that targeted mRNA was similarly regulated to miRNA. These results suggest that miRNAs of reproductive organs in dogs may be biological markers for aging and reproductive diseases and could be used for mediating aging.

Identification of Canine Pyometra-Associated Metabolites Using Untargeted Metabolomics

Canine pyometra frequently occurs in middle-aged to older intact bitches, which seriously affects the life of dogs and brings an economic loss to their owners. Hence, finding a key metabolite is very important for the diagnosis and development of a new safe and effective therapy for the disease. In this study, dogs with pyometra were identified by blood examinations, laboratory analyses and diagnostic imaging, and fifteen endometrium tissues of sick dogs with pyometra and fifteen controls were collected and their metabolites were identified utilizing a UHPLC-qTOF-MS-based untargeted metabolomics approach. The results indicated that the elevated inflammatory cells were observed in dogs with pyometra, suggesting that sick dogs suffered systemic inflammation. In the untargeted metabolic profile, 705 ion features in the positive polarity mode and 414 ion features in the negative polarity mode were obtained in endometrium tissues of sick dogs with pyometra, with a total of 275 differential metabolites (173 in positive and 102 in negative polarity modes). Moreover, the multivariate statistical analyses such as PCA and PLS-DA also showed that the metabolites were significantly different between the two groups. Then, these differential metabolites were subjected to pathway analysis using Metaboanalyst 4.0, and Galactose metabolism, cAMP signaling pathway and Glycerophospholipid metabolism were enriched, proving some insights into the metabolic changes during pyometra. Moreover, the receiver operating characteristic curves further confirmed kynurenic acid was expected to be a candidate biomarker of canine pyometra. In conclusion, this study provided a new idea for exploring early diagnosis methods and a safe and effective therapy for canine pyometra.

Effectiveness of a Modified Administration Protocol for the Medical Treatment of Feline Pyometra

Pyometra is a common uterine disease of dogs and cats, typical of the luteal phase. Traditionally, ovariohysterectomy was considered the elective treatment for pyometra, but in some cases, such as breeding subjects or patients with a high anesthesiologic risk, medical treatment is preferred. Aglepristone is a progesterone receptor blocker and its use proved to be effective for the medical treatment of pyometra in bitches and queens. The aim of this work is to report the effectiveness, in the feline species, of a modified aglepristone administration protocol. Five intact queens were referred to veterinary care centers for pyometra. Aglepristone (15 mg/kg) was administered at D0, D2, D5, and D8, as described by Contri and collaborators for dogs. An antibiotic treatment (marbofloxacin, 3 mg/kg) was associated, and uterine conditions were checked with regular ultrasonographic exams. The uterus returned to its normal condition 10 days after starting the treatment and no adverse effects were reported. After treatment, three queens had an uneventful pregnancy. Even if the treated group was restricted and homogeneous, the proposed modified protocol proved to be useful and promising for the medical treatment of pyometra in cats; further studies are planned to verify its effectiveness in the long-term prevention of recurrence.

Characterization of Escherichia coli in Dogs with Pyometra and the Influence of Diet on the Intestinal Colonization of Extraintestinal Pathogenic E. coli (ExPEC)

Despite its high frequency and clinical relevance, the pathogenesis of canine pyometra remains poorly understood. The most accepted hypothesis is that bacteria involved ascend from the intestinal tract, causing the uterine infection. Extraintestinal pathogenic Escherichia coli (ExPEC) is the most frequent pathogen in canine pyometra, accounting for 57–100% of cases. The aim of the present study was to determine the frequency of phylogenetic groups and virulence factors in E. coli strains isolated from the uterine and rectal swabs of bitches with pyometra (n = 72) and from rectal swabs from healthy bitches fed commercial dry feed (n = 53) or a raw meat-based diet (RMBD; n = 38). A total of 512 strains of E. coli were isolated and divided into five categories according to the origin of the sample: 120 isolates from the uterine content of dogs with E. coli pyometra, 102 from the feces of bitches with E. coli pyometra, 75 from the feces of bitches without E. coli pyometra, 130 feces samples from healthy dogs fed commercial feed, and 85 feces samples from healthy dogs fed a raw meat-based diet. E. coli strains belonging to the B2 phylogroup and positive for virulence factor genes associated with adhesion (fimbriae type P [papC]) and production of toxins (α-hemolysin [hlyA] and uropathogenic specific protein [usp]) predominated in the uterine content and rectal swabs of bitches with E. coli pyometra. Interestingly, a lower growth rate of E. coli from the B2 phylogroup was observed in dogs fed a RMBD than in those fed commercial dry feed. The present study suggests that intestinal colonization by certain types of E. coli could be a risk factor for the occurrence of E. coli pyometra in bitches and that diet can influence intestinal colonization by such strains.