Macroscopic,cytological and bacteriological evaluation of anal sac content in normal dogs and in dogs with selected dermatological diseases

Abstract Macroscopic and cytological aspects of anal sac content were evaluated in 40 normal dogs and 10 dogs each with pyoderma, Malassezia dermatitis associated with atopic dermatitis and uncomplicated atopic dermatitis. Bacteria isolated from anal sacs were compared with those from abdominal skin and hair in 20 normal dogs and 10 dogs with pyoderma. There was no difference between the groups in anal sac dimension, or in the colour, consistency or presence of granules in their content. Extracellular bacteria were found in higher numbers in diseased animals, whereas intracellular bacteria were observed in 40% of dogs with pyoderma and in only 2.5% of normal dogs. Malassezia spp. were present in 15.7% of dogs, with no difference between groups. Neutrophils were observed in 12.5% of normal dogs, 30% of dogs with Malassezia dermatitis with underlying atopic dermatitis and in 70 and 80% of dogs with pyoderma and uncomplicated atopic dermatitis, respectively. Seven bacterial species were isolated from anal sacs, with no difference between normal dogs and dogs with pyoderma. In five normal animals and in four dogs with pyoderma the same bacterial strains were isolated from anal sacs and from abdominal skin and hair.     

Screening of bacterial DNA in bile sampled from healthy dogs and dogs suffering from liver- or gallbladder-associated disease

Although the biliary system is generally aseptic, gallbladder microbiota has been reported in humans and some animals apart from dogs. We screened and analyzed the bacterial deoxyribonucleic acid in canine gallbladders using bile sampled from 7 healthy dogs and 52 dogs with liver- or gallbladder-associated disease. PCR screening detected bacteria in 17.3% of diseased dogs (9/52) and none in healthy dogs. Microbiota analysis of PCR-positive samples showed that the microbial diversity differed between liver- and gallbladder-associated disease groups. Thus, a specific bacterial community appears to occur at a certain frequency in the bile of diseased dogs.     

Nasal bacterial microbiota during an outbreak of equine herpesvirus 1 at a farm in southern Ontario

The objective of this study was to investigate the nasal bacterial microbiota of healthy horses and horses infected with equine herpesvirus 1 (EHV-1). The nasal bacterial microbiota of 10 horses infected with EHV-1 and 11 control horses from a farm experiencing an outbreak was characterized using the Illumina MiSeq platform targeting the V4 region of the 16S ribosomal RNA gene. The nasal bacterial microbiota of healthy horses and EHV-1 horses was significantly different in community membership and structure. Horses shedding EHV-1 had lower bacterial richness (P = 0.002), evenness (P = 0.008), and diversity (P = 0.026) than healthy horses. Healthy horses had a higher relative abundance of Firmicutes and Bacteroidetes, but lower Proteobacteria than horses with EHV-1 (P < 0.05). This study provides the basis for generating hypotheses and investigations on the role of bacterial-viral interactions in the health and diseases of adult horses.     

Disease conditions of canine anal sacs

The literature about the anal sacs of healthy dogs and the pathogenesis, diagnosis and therapy of anal sac impaction and sacculitis are reviewed. Knowledge about the physiological role of the anal sacs is still confusing. The colour and consistency of the anal sac contents are variable in healthy dogs and there are no pathognomonic signs of anal sac impaction or sacculitis. The wide variation in macroscopic detail of anal sac secretions may give rise to misinterpretation and thus overdiagnosis of sacculitis. Other diseases such as vaginitis, flea allergy, atopy, proctitis, parasites and perianal fistulae can lead to similar signs and must be eliminated from the differential diagnosis before the anal sacs are incited as the cause of the signs. Further research is necessary on the morphological, physical and biochemical aspects of the anal sacs and their secretions to define more precise criteria for the diagnosis of impaction and sacculitis. It is imperative that controlled therapeutic trials should be performed, and such studies are indispensable for the rational therapy of anal sac disease.     

Assessment of the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique

OBJECTIVE: To evaluate the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique. ANIMALS: 14 dogs (similarly housed and fed identical diets). PROCEDURE: Samples of intestinal contents were collected from the duodenum, jejunum, ileum, colon, and rectum of each dog. Bacterial DNA was extracted from the samples, and the variable V6 to V8 region of 16S ribosomal DNA (gene coding for 16S ribosomal RNA) was amplified by use of universal bacterial primers; polymerase chain reaction amplicons were separated via denaturing gradient gel electrophoresis (DGGE). Similarity indices of DGGE banding patterns were used to assess variation in the bacterial microflora among different compartments of the intestine within and among dogs. Bacterial diversity was assessed by calculating the Simpson diversity index, the Shannon-Weaver diversity index, and evenness. RESULTS: DGGE profiles indicated marked differences in bacterial composition of intestinal compartments among dogs (range of similarity, 25.6% to 36.6%) and considerable variation among compartments within individual dogs (range of similarity, 36.7% to 579%). Similarities between neighboring intestinal compartments were significantly greater than those between non-neighboring compartments. Diversity indices for the colon and rectum were significantly higher than those of the duodenum, jejunum, and ileum. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the different intestinal compartments of individual dogs appear to host different bacterial populations, and these compartmental populations vary among dogs. In dogs, fecal sample analysis may not yield accurate information regarding the composition of bacterial populations in compartments of the gastrointestinal tract.     

Immunopathology of analfurunculosis in the dog

Perianal tissue obtained from 10 normal dogs and 40 dogs with anal furunculosis was immunostained in order to determine the number and distribution of B lymphocytes/plasma cells (expressing IgG, IgM or IgA) and T lymphocytes (expressing the CD3 marker) within the inflammatory infiltrates. Differences in these parameters between tissue obtained from affected German shepherd dogs (n = 20) and affected dogs of other breeds (n = 20) were recorded. The immunological phenotype of cells comprising lymphoid follicles and associated with ductal eosinophilic pustules observed in the anal sacs of dogs with anal furunculosis is described. The results of this study suggest that a simple immunological defect does not underlie the predisposition of dogs of the German shepherd breed for anal furunculosis.     

Faecal microbiota in dogs with multicentric lymphoma

Malignant lymphoma B‐cell type is the most common canine haematopoietic malignancy. Changes in intestinal microbiota have been implicated in few types of cancer in humans. The aim of this prospective and case‐control study was to determine differences in faecal microbiota between healthy control dogs and dogs with multicentric lymphoma. Twelve dogs affected by multicentric, B‐cell, stage III‐IV lymphoma, and 21 healthy dogs were enrolled in the study. For each dog, faecal samples were analysed by Illumina sequencing of 16S rRNA genes and quantitative PCR (qPCR) for selected bacterial groups. Alpha diversity was significant lower in lymphoma dogs. Principal coordinate analysis plots showed different microbial clustering (P = .001) and linear discriminant analysis effect size revealed 28 differentially abundant bacterial groups in lymphoma and control dogs. The qPCR analysis showed significant lower abundance of Faecalibacterium spp. (q < .001), Fusobacterium spp. (q = .032), and Turicibacter spp. (q = .043) in dogs with lymphoma compared with control dogs. On the contrary, Streptococcus spp. was significantly higher in dogs with lymphoma (q = .041). The dysbiosis index was significantly higher (P < .0001) in dogs with lymphoma. In conclusion, both sequencing and qPCR analyses provided a global overview of faecal microbial communities and showed significant differences in the microbial communities of dogs presenting with multicentric lymphoma compared with healthy control dogs.     

High Throughput Sequencing to Study the Effect of Chronic Renal Failure on the Diversity and Gene Function Prediction of Gut Microbiota in Dogs

This study aimed to investigate the effect of chronic renal failure(CRF) on the gut microbiota diversity and predict the gene function of the flora. A total of 30 2-year-old dogs were selected and randomly divided into the chronic renal failure model group (CRF, established by renal artery ligation), sham operation control group (Sham) and healthy control group (HCG). All animals were fed normally during the 56 days of test period. The serum creatinine (Scr), blood urea nitrogen (BUN) and urine protein / creatinine ratio (UP/C) were detected regularly during the experiment. The effects of chronic renal failure on the structure, diversity and function of gut microbiota were analyzed according to the result of bacterial 16S rDNA sequencing from fresh feces collected without contamination. The flora markers index (FMI) was constructed based on the principal component Logistic regression analysis of different microbiota in CRF group to predict the development of chronic renal failure. The results showed that: 1) The levels of Scr, BUN and UP/C in CRF group from the start of the 28th day of the experiment were significantly higher than those of HCG group and Sham group (P<0.05), and significantly higher than that of the first day of CRF group (P<0.05). 2) Compared with those before chronic renal failure (CRF group at day 0 and 28), HCG group and Sham group, the Chao 1 diversity and Shannon diversity of gut microbiota in CRF group at day 56 were significantly lower (P<0.05), while the relative abundance of Bacteroidetes, Proteobacteria and Actinobacteria significantly increased and the number of Firmicutes significantly decreased (P<0.05). 3) LEfSe analysis showed that 20 species were enriched in CRF group, mainly including Pseudomonas, Escherichia, Proteus and so on, and most of them had negative correlation with other intestinal bacteria. Functional prediction revealed that genes of those different species were mainly enriched in amino acid metabolism, sugar biosynthesis and metabolism and carbohydrate metabolism in CRF group. The area under ROC curve (AUC) of the FMI constructed with those species enriched was 0.788, which could be used as the intestinal microbial marker for CRF in dogs. In summary, chronic renal failure can reduce the diversity of intestinal microbiota, lead to the imbalance of bacterial structure and change of bacterial function. Moreover, the enriched gut microbiota in CRF group can be used as the intestinal microbial marker of CRF in dogs, and the best prediction effect can be obtained by FMI.     

高通量测序研究慢性肾衰竭对宠物犬肠道菌群多样性的影响及基因功能预测分析

旨在通过高通量测序研究慢性肾衰竭（chronic renal failure,CRF）对宠物犬肠道菌群多样性的影响,并预测分析菌群的基因功能。本研究选取30只2岁健康犬,随机等分为慢性肾衰竭模型组（CRF,肾动脉结扎法制备）、假手术对照组（Sham）和健康对照组（HCG）,常规饲养,试验周期56 d。试验过程中,定期检测血肌酐（Scr）、血尿素氮（BUN）和尿蛋白/肌酐比（UP/C）,无菌采集新鲜粪便进行细菌16S rDNA测序,分析慢性肾衰竭对犬肠道菌群结构、多样性与功能的影响,并以CRF组差异菌群为自变量进行主成分Logistic回归分析,构建菌群标志物综合指数（FMI）用于慢性肾衰竭预测。结果显示：1）从试验后第28天开始,CRF组Scr、BUN和UP/C分别显著高于自身试验前、HCG组和Sham组（P<0.05）。2） CRF组不同时间点肠道菌群有显著差异,第56天时的Chao 1指数、Shannon指数均降低,拟杆菌门（Bacteroidetes）、变形杆菌门（Proteobacteria）和放线菌门（Actinobacteria）的相对丰度增加,厚壁菌门（Firmicutes）数量减少,与0 d和28 d比较差异显著（P<0.05）,与同时间点HCB组及Sham组比较差异显著（P<0.05）。3）组间菌群LEfSe分析发现,CRF组富集了20个物种,主要包括假单胞菌属（Pseudomonas）、埃希氏菌属（Escherichia）和变形杆菌属（Proteus）等,这些物种与肠道其他菌属间多呈负相关关系;差异物种基因主要富集在氨基酸代谢、糖生物合成和代谢以及碳水化合物代谢等代谢途径。用这些差异物种构建的FMI,其ROC曲线AUC为0.788,可作为犬CRF的肠道微生物标志物。以上结果表明,慢性肾衰竭可以使犬肠道菌群多样性降低、菌群结构失调以及菌群功能改变,且CRF患犬肠道中富集的菌群可作为该病的肠道微生物标志物,以FMI预测效果最好。     

犬慢性肾衰竭进程中肠道菌群代谢物短链脂肪酸水平的变化及其对肾功能的影响

本研究旨在评估短链脂肪酸在慢性肾衰竭患犬和健康犬中的水平,探究短链脂肪酸变化的原因及其对肾功能的影响.选取22例轻度慢性肾衰患犬(M-CRF组)、29例重度慢性肾衰患犬(S-CRF组)和26例健康对照犬(HC组),用16S rDNA测序技术分析肠道菌群多样性,气相色谱法检测粪中短链脂肪酸浓度.通过粪菌移植和补充丁酸钠给...     

Comparison of anal sac cytological findings and behaviour in clinically normal dogs and those affected with anal sac disease

No previous study has explored the relationship between cytology and the frequency of behaviours associated with anal sac disease (ASD). The goals of the study were: (i) to compare the cytological findings between anal sac secretions from normal dogs with no history of ASD to those with non-neoplastic ASD; (ii) to determine whether anal sac cytological findings can be used to differentiate between normal dogs and dogs with ASD; (iii) to explore the correlation of anal sac cytology and behaviour between normal dogs and dogs with ASD; and (iv) to describe behaviours typical of ASD as reported by owners. Thirty dogs were selected for this study, based on their behavioural history as detailed in a questionnaire completed by their owners. Of the thirty dogs, ten were considered normal insofar as they had no history of ASD clinical signs. The remaining 20 dogs were characterized as having ASD, with a chronic history of perianal pruritus, but no other pruritus. All dogs had their anal sacs manually expressed, and the discharge was examined microscopically in a blinded manner. A total of 171 oil immersion fields (OIFs) were examined from normal dogs and 333 OIFs from dogs with ASD. The behavioural results for dogs with ASD revealed that scooting recurred with a median frequency of 3 weeks post-anal sac expression. There were no clinically statistically significant cytological differences between normal dogs and those with ASD, thereby leading to the conclusion that cytology is an ineffective tool for diagnosing ASD.     

COMPARISON OF DOPPLER-DERIVED AORTIC VELOCITIES OBTAINED FROM VARIOUS TRANSDUCER SITES IN HEALTHY DOGS AND CATS

In normal dogs and dogs with subaortic stenosis, it is known that the subcostal transducer site provides higher left ventricular ejection velocities than does the left apical site. We hypothesized that aortic flow velocities could also be obtained from the right parasternal long-axis view, optimized for the placement of the Doppler cursor as parallel as possible into the aortic root. In 15 healthy dogs and 13 healthy cats, high-pulsed repetition frequency Doppler flow velocity measurements in the proximal aorta were performed using two-dimensional echocardiographic guidance. The mean [ +/- standard error of the mean (SEM)] peak aortic flow velocities in healthy dogs were as follows: subcostal site 1.46 +/- 0.05 m/s; apical site 1.12 +/- 0.06 m/s; right parasternal long-axis site 1.09 +/- 0.05 m/s. In healthy cats, the following peak aortic flow velocities were observed: apical site 0.87 +/- 0.03m/s; right parasternal long-axis site 0.87 +/- 0.03 m/s. Aortic flow velocities obtained from the subcostal site were significantly higher in healthy dogs than those obtained from the left apical and right parasternal long-axis site (P< 0.001). There was no statistical difference between the peak aortic flow velocities obtained from right parasternal long-axis and left apical transducer position in all groups. We conclude therefore that right parasternal long-axis and left apical-derived aortic flow velocities are similar and may be used interchangeably in healthy dogs and cats.     

Ultrasonographic evaluation of the adrenal glands in healthy dogs: repeatability, reproducibility, observer-dependent variability, and the effect of bodyweight, age and sex

Adrenal length and width were determined from two-dimensional ultrasound longitudinal images. In study 1, 540 measurements of adrenal glands were attempted from five healthy beagle dogs by three different observers with different levels of expertise in ultrasonography, to determine the variability of adrenal gland measurements. Of these, 484 measurements were included in the statistical analysis, since 16 measurements of the left adrenal gland and 40 for the right could not be visualised by the observer. In study 2, a single measurement of both adrenal glands was taken from each of 146 dogs by the most trained observer from study 1, and the effects of different health status (healthy dogs v dogs with non-adrenal diseases), bodyweight, age and sex were assessed. A total of 267 measurements were included in the statistical analysis. The lowest intra- and inter-day coefficient of variation values were observed for the left adrenal gland and by the most trained observer. The health status had no statistically significant effect on adrenal gland length or width, whereas age had a significant effect only for the left adrenal gland (the greater the age, the greater the width or length) and sex had a significant effect only for the right adrenal gland (the width was larger in males and the length larger in females). The bodyweight had a significant effect for the length of both adrenal glands (the greater the bodyweight, the greater the length), but not the width. The differences between sd and coefficient of variation values for the width of the left adrenal gland were not statistically significant between the three observers, whereas they were statistically significant for the right adrenal gland.     

Anal sac tumours of the dog and their response to cytoreductive surgery and chemotherapy

A retrospective study of anal sac tumours without pulmonary metastases, from the author's clinical records for the period July 1989 to July 2002, was conducted to establish the response to treatment with surgery and melphalan chemotherapy. Of 21 dogs with tumours of the anal sacs 19 had apocrine gland adenocarcinomas of anal sac origin, one had a benign papillary cystadenoma and another had a malignant melanoma. Two of the 19 dogs had bilateral anal sac adenocarcinomas. Ten of the 19 dogs with apocrine gland adenocarcinomas of anal sac origin had sublumbar lymphadenopathy. Five dogs were excluded by their owners from recommended treatment. Fourteen dogs with apocrine gland adenocarcinomas of anal sac origin were treated by surgical cytoreduction and chemotherapy with melphalan. Seven of the 14 dogs had regional lymph node metastases. Cytoreduction was by local excision of the anal sac in all 14 dogs and concurrent removal of the sublumbar retroperitoneal lymph nodes in the seven dogs with regional lymph node metastases. The median survival time of dogs with sublumbar nodal metastasis was 20 months and for dogs with tumour localised to the anal sac the median survival time was 29.3 months. There was no difference in median survival of those dogs with sublumbar metastases compared to those without. This study suggests there is a role for melphalan in the treatment of dogs with anal sac adenocarcinoma when combined with cytoreductive surgery, with treatment survival times and the local recurrence rate of the primary tumour comparing favourably with previously published treatment regimes.     

Quantitative assessment of regional right ventricular myocardial velocities in awake dogs by Doppler tissue imaging: repeatability, reproducibility, effect of body weight and breed, and comparison with left ventricular myocardial velocities

Right ventricular myocardial (RVM) motion is poorly documented. The objective of this study was to determine the variability of RVM velocities by tissue Doppler imaging (TDI) in healthy dogs (study 1), to analyze RVM motion in a large healthy canine population (study 2), and to compare the results with those obtained for the left ventricular free wall. Six healthy Beagle Dogs were monitored in study 1, and 64 healthy dogs of 14 different breeds were monitored in study 2. Velocities were recorded in 2 segments (basal and apical) of the right and left myocardial walls. In study 1, 36 TDI examinations were performed for 4 days, whereas a single TDI examination was performed on each dog in study 2. All velocity profiles included 1 positive systolic wave and 2 negative diastolic waves. The lowest intraday and interday coefficient of variation values of the right TDI variables were observed at the base (3.5-16.1%). The variability of the right apical velocities was much higher, with most coefficient of variation values > 15%. RVM velocities were higher in the basal than in the apical segments (P < .001) and were higher than the left velocities of the corresponding segment (P < .01). Body weight and breed had an effect on only a few right and left TDI variables. TDI provides a repeatable and reproducible method for evaluating basal RV function in the dog. These data also demonstrate the heterogeneity of the myocardial velocities between the left and the right ventricles and between the base and the apex.     

Cytological examination and physical characteristics of the anal sacs in 17 clinically normal dogs

OBJECTIVE: To quantify numbers of leucocytes, keratinocytes and microorganisms in, as well as the turgidity, colour and consistency of, anal sac exudates in clinically normal dogs. DESIGN: Selection criteria were formed based on the absence of clinical signs associated with anal sac disease, and the absence of factors potentially affecting colonic flora. Anal sacs were palpated for turgidity then expressed onto a swab, where colour and consistency were noted. A squash preparation made from any exudate was heat fixed and stained with modified Wright's stain. Eight representative 1000x oil immersion fields from each were examined for leucocytes, erythrocytes, keratinocytes, bacteria and yeast. Results were summarised, and cytological counts grouped into quartiles (minimal, few, moderate, numerous). Due to the multivariate nature of the study and limited subject numbers, further significant statistical analysis could not be performed. RESULTS: Seventeen dogs satisfied the selection criteria. The physical characteristics of the exudate and sac varied, though 31/34 sacs were empty or soft, 22/27 exudates were light or dark brown and 19/27 exudates were a thin liquid. Total leucocyte, keratinocyte and bacilli counts were extremely variable. Yeasts were present in 26/208 microscopic fields examined cytologically. Only 5/208 fields showed numerous cocci. A single instance of intracellular bacteria and a single erythrocyte were noted following examination of all fields. CONCLUSION: In this study, the characteristics of normal anal sacs and their exudate varied but greater than 70% showed similar features. Exudate cytology was highly variable, though yeasts were uncommon, and intracellular cocci and erythrocytes extremely rare.     

Gross and cytological characteristics of normal canine anal-sac secretions

A study was conducted to characterize the gross and cytological characteristics of secretions from normal canine anal sacs. Fifty dogs with no recent history of anal-sac disease were selected consecutively and their anal sacs manually expressed. Of the 47 dogs with known or estimated ages, 27 were < 1 year olds. However, these youngest dogs were not significantly different from the rest in cell counts, viscosity, or presence of dark or light solid portions of the secretions. For all dogs combined, the secretions typically contained 41 (median) corneocytes per 400x magnification microscopic field, lots of basophilic background debris, and a mixture of Gram-positive cocci (173 per field; median), Gram-positive rods (29 per field; median), and Gram-negative rods (two per field; median). Although median counts across 10 400x fields per sac indicated no leucocytes or yeasts, many of the normal dogs had an occasional 400x field with non-degenerate neutrophils and yeasts. Erythrocytes were not a feature of these anal-sac secretions, and mononuclear leucocytes were found only rarely. Extreme heterogeneity existed in gross colour, consistency and the amount of solid material. Thus, these latter parameters probably would not be valid indicators of anal-sac disease.     

Gross morphological features of the air sacs of the hooded crow (Corvus cornix)

Air sacs are considered to be one of the controlling factors of bird behaviour and habits in addition to their roles in ventilation, regulating body temperature, swimming and flight. As a scavenger and an omnivorous flight bird, air sacs of the hooded crow were the focus of this study. Eight healthy, adult hooded crows were used to examine the morphological characteristics of the air sacs, which were examined grossly and with latex and cast preparations. In general, the morphological overview of the hooded crow air sacs is similar to other avian species. We observed nine air sacs; four paired sacs (cervical, cranial thoracic, caudal thoracic and abdominal air sacs) and one unpaired sac; the clavicular air sac. The cervical air sac communicated to the lung through the medioventral bronchus and had three diverticula; intermuscular, subscapular and subcutaneous. The clavicular air sac communicated with lung through the medioventral bronchus and had subscapular, axillary, humeral, subpectoral and sternal diverticula. The cranial and caudal thoracic air sacs were communicated with lung through the lateroventral bronchi and the both sacs did not have any diverticula. The abdominal air sacs were posterior to the caudal thoracic air sacs. The left abdominal sac was the largest air sac. The right and left abdominal sacs gave off branches to diverticula that pneumatized synsacrum. The abdominal air sacs gave off femoral diverticula behind the hip joint as well as perirenal diverticula.     

腹泻犊牛与健康犊牛粪便菌群结构组成与功能研究

本研究旨在探究腹泻与健康犊牛粪便微生物的结构组成与分布特征,筛选出一些可作为评价犊牛腹泻参考指标的特异性菌群。试验采集10份腹泻和10份健康夏南牛犊牛的粪便样本并提取粪便总DNA,运用16S rRNA高通量测序技术,比较腹泻组和健康组在微生物多样性方面（组成及结构）存在的差异,获得两组间具有统计学差异的Biomarker,并对差异功能基因进行注释。结果表明,腹泻犊牛粪便微生物的多样性小于健康犊牛;在门水平上,与健康组相比,腹泻组犊牛粪便中微生物相对丰度显著升高的是变形菌门和梭杆菌门,螺旋菌门显著降低（P<0.05）;在属水平上,与健康组相比,腹泻组犊牛粪便微生物中埃希氏-志贺菌属、梭杆菌属、乳杆菌属和梭状芽孢杆菌属相对丰度明显升高,不可培养拟杆菌目S24-7群、拟普雷沃菌属和普雷沃氏菌科的菌属显著降低（P<0.05）。通过对COG功能预测分析,腹泻组在翻译、核糖体结构和起源类群明显降低。通过KEGG代谢途径分析,腹泻组粪便中显著升高的代谢通路是碳水化合物代谢和外源性物质降解和代谢,显著降低的代谢通路分别是细胞增殖和死亡、复制和修复、翻译和转录（P<0.05）。本研究分析了腹泻组和健康组之间的优势菌群,筛选出可以作为犊牛腹泻参考指标的10个Biomarker,并对功能差异基因进行注释,为进一步研究犊牛腹泻的治疗及预防奠定了基础。