Duodenal and colonic mucosal S100A8/A9 (calprotectin) expression is increased and correlates with the severity of select histologic lesions in dogs with chronic inflammatory enteropathy

BACKGROUND

Calprotectin, a damage-associated molecular pattern protein of the S100/calgranulin family, is a potential marker of gastrointestinal inflammation in dogs and mainly originates from activated macrophages and granulocytes. Increased calprotectin concentrations are reported in feces and serum samples from dogs with chronic inflammatory enteropathy (CIE), but mucosal calprotectin expression has not been extensively investigated in canine CIE. Thus, we aimed to evaluate gastrointestinal mucosal concentrations of calprotectin in 62 dogs (44 dogs with CIE compared to 18 healthy Beagles) using a particle-enhanced turbidimetric immunoassay method. Additionally, we assessed the relationship of gastric, duodenal, jejunal, ileal, and colonic mucosal calprotectin levels with the clinical disease severity (canine clinical inflammatory bowel disease activity index, CIBDAI), histopathologic findings, clinical outcome, and serum albumin concentrations to further evaluate the potential of calprotectin as a biomarker for CIE.

RESULTS

Mucosal calprotectin concentrations in dogs with CIE were significantly higher in the duodenum (median: 276.2 μg/g) and colon (median: 298.2 μg/g) compared to healthy controls (median: 94.3 μg/g, P = 0.0039; and median: 112.0 μg/g, P = 0.0061). Similar numerical differences in the ileum and cecum were not statistically significant, and mucosal calprotectin concentrations correlated significantly among the different gastrointestinal segments. Histologic lesion severity was linked to mucosal calprotectin concentrations for inflammatory and structural histology criteria in the duodenum and colon (all P < 0.05). Higher mucosal calprotectin levels in the duodenum and across all segments correlated with lower serum albumin concentrations (both P < 0.05); duodenal mucosal calprotectin concentrations were more than sixfold higher in hypoalbuminemic dogs (median: 1441 µg/g, n = 4) than normoalbuminemic dogs (median: 227 µg/g, n = 40). There was no significant association of mucosal calprotectin levels with CIBDAI scores or individual clinical outcomes.

CONCLUSIONS

These results show that duodenal and colonic mucosal calprotectin concentrations are increased in dogs with CIE, providing further supporting evidence for the diagnostic potential of fecal calprotectin (presumably reflecting mucosal) concentrations and in dogs with CIE. Further longitudinal research is needed to assess changes in mucosal calprotectin concentrations with clinical response to treatment vs. mucosal disease remission and to determine the clinical utility of fecal calprotectin concentrations to diagnose and monitor dogs with CIE in clinical practice.

Long-term evaluation of the initial response to therapy in 60 dogs with chronic inflammatory enteropathy

BACKGROUND

Dogs with chronic inflammatory enteropathy (CIE) are typically classified into food-responsive enteropathy (FRE), antibiotic-responsive enteropathy (ARE), immunomodulator-responsive enteropathy (IRE), and nonresponsive enteropathy (NRE) based on response to therapy(ies). Reassessment of initial categorization (especially IRE and NRE) is lacking.

OBJECTIVES

Investigate validity of categorization scheme when reassessed at least 1 year after diagnosis.

ANIMALS

Sixty client-owned dogs with CIE.

METHODS

Retrospective study. Clinical information was gathered from records and owners from time of diagnosis (TD), time of initial response (TIR), and at least 1 year after diagnosis (T≥1y). Category change was defined as a switch between groups.

RESULTS

Median disease activity index (CIBDAI) at TD was 9 and reduced significantly to 1 at T≥1y (P < .0001). At TIR, dogs were categorized as: FRE 27/60 (45%, 95% binomial confidence intervals [CI], 0.32-0.58), IRE 30/60 (50%, CI 0.37-0.63), ARE 0/60 (0%), NRE 3/60 (5%, CI -0.01 to 0.11). Seventeen of 27 (63%) FRE dogs had previously had at least 1 unsuccessful diet trial. At T≥1y, categorization changed to FRE 44/60 (73%, CI 0.62-0.85), IRE 14/60 (23%, CI 0.13-0.34), ARE 0/60 (0%), NRE 2/60 (3%, CI -0.01 to 0.08). Group changes were found for 24/60 (40%) dogs, largest change was from IRE to FRE (19/24, 79%). Immunosuppressive dosages were administered as sole treatment in 1/30 (3%) IRE dogs at TIR.

CONCLUSIONS AND CLINICAL IMPORTANCE

Chronic inflammatory enteropathy categorization based on initial response to therapy needs reassessment after 1 year. Frequent change from IRE to FRE suggests that dogs initially categorized as IRE might have been initially categorized as FRE if multiple dietary trials had been performed. In our study, antibiotics were not needed to achieve satisfying clinical responses.

Characterization of faecal microbiota and serum inflammatory markers in dogs diagnosed with chronic enteropathy or small-cell lymphoma: a pilot study

Dogs diagnosed with chronic enteropathy (CE) or small-cell lymphoma (SCL) exhibit marked differences in faecal microbiota and organic acid profiles compared with healthy dogs, as well as immune abnormalities in intestinal mucosal tissue. However, few studies have analysed trace organic acids, such as succinic acid, which have been suggested to be associated with IBD in humans. Therefore, in this study, we compared the faecal microbiota and organic acid profiles as well as serum inflammatory markers between dogs with disease (n = 11; 6 with CE and 5 with SCL) and healthy controls (n = 16). We also performed machine learning and correlation analysis to obtain more detailed insights into the characteristics of affected dogs. These results revealed that dogs with CE and SCL had lower levels of Erysipelotrichaceae (e.g. Turicibacter and Allobaculum), exhibited abnormalities in the succinic acid metabolism (i.e. succinic acid accumulation and decreased levels of Phascolarctobacterium as succinic acid-utilising bacteria) and increased levels of pathobiont bacteria such as Escherichia-Shigella. Additionally, the presence of Dubosiella was significantly negatively correlated with Canine Inflammatory Bowel Disease Activity Index scores. These findings are expected to aid the development of microbiome-based medications and/or supplements, although further verification is needed.

Approach to Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) in the horse encompasses a group of infiltrative gastrointestinal disorders resulting in malabsorption, maldigestion, weight loss, colic, and sometimes diarrhea. The type of IBD can be classified as granulomatous, lymphocytic-plasmacytic, or eosinophilic enterocolitis. The diagnosis of IBD in equids is based on consistent clinical signs and clinicopathologic findings in conjunction with confirmatory histopathology from a gastrointestinal biopsy. Treatment usually consists of a combination of immunosuppressive medications, anthelmintics, and dietary modifications. The prognosis of IBD in horses is variable and dependent on the horse's response to treatment; however, horses can show improvement or resolution of clinical signs.

Evaluation of the fatty acid-based erythrocyte membrane lipidome in cats with food responsive enteropathy, inflammatory bowel disease and low-grade intestinal T-cell lymphoma

Feline chronic enteropathies (FCE), include food-responsive-enteropathy (FRE), inflammatory bowel disease (IBD), and low-grade intestinal T-cell lymphoma (LGITL), and are common causes of chronic gastrointestinal signs in cats. Distinguishing between different subgroups of FCE can be challenging due to the frequent overlap of anamnestic, clinical, and laboratory data. While dysregulation in lipid metabolism has been reported in humans and dogs with chronic IBD, similar changes in cats are not yet completely understood. Assessing the fatty acid (FA) profile of red blood cell (RBC) membranes offers a valuable method for evaluating the quantity and quality of structural and functional molecular components in the membranes. Therefore, this study aimed to examine the FA composition of RBC membranes in FCE in comparison to healthy cats (HC). Gas-chromatography was used to quantitatively analyze a cluster of 11 FA, and based on these results, parameters of lipid homeostasis and enzyme activity indexes were calculated. A total of 41 FCE cats (17 FRE, 15 IBD, 9 LGITL) and 43 HC were enrolled. In FCE cats, the values of docosapentaenoic acid (p = 0.0002) and docosahexaenoic acid (p = 0.0246), were significantly higher, resulting in an overall increase in ω-3 polyunsaturated fatty acids (PUFA) (p = 0.006), and that of linoleic acid (p = 0.0026) was significantly lower. Additionally, FCE cats exhibited an increased PUFA balance (p = 0.0019) and Δ6-desaturase index (p = 0.0151), along with a decreased ω-6/ω-3 ratio (p = 0.0019). No differences were observed among cats affected by FRE, IBD and LGITL. Like humans and dogs, the results of this study indicate that FCE cats also display changes in their FA lipid profile at the level of the RBC membrane. The non-invasive analysis of RBC membrane shows promise as a potential tool for gaining a better understanding of lipid imbalances in this disease.

Peripheral and intestinal T lymphocyte subsets in dogs with chronic inflammatory enteropathy

BACKGROUND

Dysregulated T lymphocyte response is thought to play a key role in chronic intestinal inflammation (CIE).

OBJECTIVES

To evaluate the presence of changes in peripheral and intestinal T lymphocyte subsets and to describe potential immune and inflammatory biomarkers in dogs with CIE.

ANIMALS

Sixteen healthy dogs and 26 dogs were diagnosed with CIE.

METHODS

Prospective case-control study evaluating peripheral and intestinal T lymphocytes using flow cytometry and inflammatory markers obtained from complete blood cell counts.

RESULTS

Dogs with CIE had higher peripheral activated T helper (Th) lymphocytes (87/μL [18-273] CIE, 44/μL [16-162] healthy control (HC, P = .013) and regulatory T cells (Treg; 108/μL [2-257] CIE, 34/μL [1-114] HC, P = .004). In the intestinal epithelium, CIE dogs presented lower percentages of Th (4.55% [1.75-18.67] CIE, 8.77% [3.79-25.03] HC, P = .002), activated Th cells (0.16% [0.02-0.83] CIE, 0.33% [0.05-0.57] HC, P = .03) and CD4/CD8 ratio (0.08 [0.02-0.39] CIE, 0.21 [0.07-0.85] HC, P = .003). Conversely, higher percentage of activated T cytotoxic cells (20.24% [3.12-77.12] CIE, 12.32% [1.21-39.22] HC, P = .04) and interferon-gamma (IFN-γ) producing T lymphocytes (7.36% [0.63-55.83] CIE, 1.44% [0.00-10.56] HC, P = .01) within the epithelium was observed. In the lamina propria the percentage of Treg lymphocytes was higher (6.02% [1.00-21.48] CIE, 3.52% [0.18-10.52] HC, P = .02).

CONCLUSIONS AND CLINICAL IMPORTANCE

Systemic and intestinal immune alterations occur in dogs with CIE suggesting that blood IFN-γ producing T lymphocytes and the systemic immune-inflamation index (SII) could potentially serve as biomarkers for the disease.

Efficacy and tolerance of oral versus parenteral cyanocobalamin supplement in hypocobalaminaemic dogs with chronic enteropathy: a controlled randomised open-label trial

OBJECTIVES

Determine comparative tolerance of daily oral and weekly parenteral cobalamin supplementation, in hypocobalaminaemic dogs with chronic enteropathy. Determine whether oral is as effective as parenteral supplementation at achieving eucobalaminaemia, in hypocobalaminaemic dogs with protein-losing enteropathy, severe hypocobalaminaemia or high canine inflammatory bowel disease activity index at inclusion.

MATERIALS AND METHODS

Thirty-seven client-owned dogs with hypocobalaminaemia and clinical signs of chronic enteropathy were prospectively enrolled in three UK referral centres. Dogs were randomly allocated to daily oral for 12 weeks or weekly parenteral cobalamin supplementation for 6 weeks and one additional dose 4 weeks later. Serum cobalamin, body condition score, canine inflammatory bowel disease activity index and bodyweight were assessed at inclusion, weeks 7 and 13. Serum methylmalonic acid concentration was evaluated at inclusion and at week 13. Owners completed treatment adherence, palatability, tolerance and satisfaction questionnaires at week 13.

RESULTS

Nineteen dogs completed the study. All dogs orally supplemented achieved normal or increased cobalaminaemia at weeks 7 and 13. There was no statistical difference in cobalamin concentration at week 13 in dogs treated with oral or parenteral supplementation, regardless of presence of protein-losing enteropathy, severity of hypocobalaminaemia or canine inflammatory bowel disease activity index at inclusion. Serum methylmalonic acid concentration was not significantly different between oral and parenteral groups, neither were treatment adherence, satisfaction, and tolerance scores at week 13.

CLINICAL SIGNIFICANCE

Oral is as effective and as well-tolerated as parenteral cobalamin supplementation in hypocobalaminaemic dogs with chronic enteropathy and severe clinical or biochemical phenotypes, and should be considered as a suitable treatment option regardless of disease severity.

Oxidative stress in dogs with chronic inflammatory enteropathy treated with allogeneic mesenchymal stem cells

The search for new biomarkers in patients with chronic inflammatory enteropathy (CIE) is ongoing in the human and veterinary medicine fields. Oxidative stress biomarkers (malondialdehyde [MDA], reduced glutathione [GSH], and albumin) have been studied in humans with chronic enteropathies, but among them, only albumin has been studied in dogs with CIE. Moreover, the effect of mesenchymal stem cell (MSCs) treatment with or without prednisone on these parameters has never been studied in dogs with CIE. These parameters were compared between healthy dogs (n = 12) and dogs with CIE, and before and 1, 3, 6, and 12 months after the treatment with MSCs alone (n = 9) or together with prednisone (n = 11). The relationship between the Canine Inflammatory Bowel Disease Activity Index (CIBDAI) and oxidative stress was evaluated. Albumin was the only parameter that significantly differed between dogs with CIE and healthy dogs (p = 0,037). Differences were observed only in albumin values after combined treatment with MSCs and prednisone. No differences were observed in MDA and GSH after treatment with MSCs with or without prednisone. Albumin could help stage canine CIE, as well as its prognosis, as has already been demonstrated, although it is essential to evaluate this parameter for its antioxidant capacity, and therefore it could be a good biomarker of oxidative stress in this pathology. However, the treatment with MSCs seems unable to modify any of the analyzed oxidative stress parameters.

Heterogeneity of mesenchymal stem cells as a limiting factor in their clinical application to inflammatory bowel disease in dogs and cats

Inflammatory bowel disease (IBD) is a major subtype of chronic enteropathies in dogs and cats. Conventional drugs such as immunomodulatory medicines as glucocorticoids and/or other anti-inflammatory are mainly applied for treatment. However, these drugs are not always effective to maintain remission from IBD and are limited by unacceptable side effects. Hence, more effective and safe therapeutic options need to be developed. Mesenchymal stem cells (MSCs) are multipotent stem cells with a self-renewal capacity, and have immunomodulatory, anti-inflammatory, anti-fibrotic, and tissue repair properties. Therefore, the application of MSCs as an alternative therapy for IBD has great potential in veterinary medicine. The efficacy of adipose tissue-derived MSC (ADSC) therapy for IBD in dogs and cats has been reported, including numerous studies in animal models. However, treatment outcomes in clinical trials of human IBD patients have not been consistent with preclinical studies. MSC-based therapy for various diseases has received widespread attention, but various problems in such therapy remain, among which no consensus has been reached on the preparation and treatment procedures for MSCs, and cellular heterogeneity of MSCs may be an issue. This review describes the current status of ADSC therapy for canine and feline IBD and summarizes the cellular heterogeneity of canine ADSCs, to highlight the necessity for further reduction or elimination of MSCs heterogeneity and standardization of MSC-based therapies.

Intestinal full-thickness needle-core biopsy via laparotomy is safe, rapid, and effective and less invasive than standard incisional biopsy in dogs and cats

OBJECTIVE

To describe the intestinal full-thickness needle-core biopsy technique via abdominal laparotomy outcomes and compare the histopathological and immunohistochemical diagnosis with standard incisional intestinal biopsy technique in dogs and cats.

ANIMALS

3 dogs and 17 cats.

METHODS

Client-owned dogs and cats were prospectively enrolled if intestinal full-thickness biopsies were indicated for the diagnosis of diffuse chronic intestinal diseases following ultrasonography. The study period extended from June 2021 to December 2022. All animals underwent intestinal biopsies with both techniques (needle-core biopsy and standard incisional biopsy) via abdominal laparotomy. Data collected included clinical signs, biopsy collection times, complications, and histopathologic and immunohistochemical findings. A minimum follow-up of 14 days was required.

RESULTS

The main clinical sign at presentation was chronic vomiting (65%). Mean needle-core biopsy collection time (262 seconds) was significantly shorter than standard incisional biopsy collection time (599 seconds; P < .000001). The incidence of minor complications was 10% (inflammation of the skin surgical site secondary to licking). One catastrophic complication occurred on a standard incisional biopsy site in 1 cat in a context of bile peritonitis (5% of all cases). There were no complications associated with the needle-core biopsy. All but 1 cat were discharged, with a median of 2 days (range, 1 to 4 days) after surgery. The diagnoses resulting from both techniques were 100% concordant for the distinction between inflammatory bowel disease and intestinal lymphoma via histopathology and immunochemistry.

CLINICAL RELEVANCE

Needle-core biopsy is safe, rapid, and effective and is less invasive than standard incisional biopsy.

Application of automated machine learning for histological evaluation of feline endoscopic samples

Differentiating intestinal T-cell lymphoma from chronic enteropathy (CE) in endoscopic samples is often challenging. In the present study, automated machine learning systems were developed to distinguish between the two diseases, predict clonality, and detect prognostic factors of intestinal lymphoma in cats. Four models were created for four experimental conditions: experiment 1 to distinguish between intestinal T-cell lymphoma and CE; experiment 2 to distinguish large cell lymphoma, small cell lymphoma, and CE; experiment 3 to distinguish granzyme B+ lymphoma, granzyme B- lymphoma, and CE; and experiment 4 to distinguish between T-cell receptor (TCR) clonal population and TCR polyclonal population. After each experiment, a pathologist reviewed the test images and scored for lymphocytic infiltration, epitheliotropism, and epithelial injury. The models of experiments 1-4 achieved area under the receiver operating characteristic curve scores of 0.943 (precision, 87.59%; recall, 87.59%), 0.962 (precision, 86.30%; recall, 86.30%), 0.904 (precision, 82.86%; recall, 80%), and 0.904 (precision, 81.25%; recall, 81.25%), respectively. The images predicted as intestinal T-cell lymphoma showed significant infiltration of lymphocytes and epitheliotropism than CE. These models can provide evaluation tools to assist pathologists with differentiating between intestinal T-cell lymphoma and CE.

A RETROSPECTIVE STUDY OF DISEASE PROCESSES IN MANED WOLVES (CHRYSOCYON BRACHYURUS) IN NORTH AMERICAN ZOOLOGICAL INSTITUTIONS WITH EMPHASIS ON UROLITHIASIS, INFLAMMATORY BOWEL DISEASE, AND NEOPLASIA

The objective of this retrospective study is to summarize causes of disease and mortality in maned wolves (Chrysocyon brachyurus) in the North American Species Survival Plan Program (SSP) population. This information will inform and enhance animal health, husbandry, and conservation efforts. Pathology reports were requested from all zoological institutions housing maned wolves between 1930 and 2021. Data were reviewed and cause of death (COD) and reported diseases were summarized and compared by age group, organ system and disease process. One hundred and seventy-one wolves, 82 females and 89 males, met the inclusion criteria. The majority were geriatric (>11 yr; n = 96) or adult (2-11 yr; n = 67). Noninfectious diseases were the most common COD by process (n = 94; 54.9%). For COD by organ system, diseases of the digestive (n = 41) and urinary (n = 34) systems were most common. Neoplasia was the most common noninfectious COD and was the primary COD in 37 wolves (21.6% overall; 39.4% of noninfectious diseases). A total of 145 benign (n = 72) and malignant (n = 73) neoplasms were diagnosed in 44 individuals. Dysgerminoma was the most commonly reported tumor (n = 18), and was the most common neoplastic COD (n = 8). Cystinuria or urolithiasis (n = 71) and gastritis, enteritis, enterocolitis, or colitis (n = 50) (overall and grouped in each system due to presumed common underlying cause) were also common but were more often reported as comorbidities than as COD (n = 16 and n = 11, respectively). Infectious COD were reported in 17 wolves and included babesiosis (n = 4), acanthocephalans (n = 2), and one viral infection. Infections with a variety of bacteria in different organ systems were a COD in eight wolves.

Traces of Canine Inflammatory Bowel Disease Reflected by Intestinal Organoids

Inflammatory bowel disease (IBD) is a chronic inflammatory condition that affects humans and several domestic animal species, including cats and dogs. In this study, we have analyzed duodenal organoids derived from canine IBD patients using quantitative proteomics. Our objective was to investigate whether these organoids show phenotypic traits of the disease compared with control organoids obtained from healthy donors. To this aim, IBD and control organoids were subjected to quantitative proteomics analysis via liquid chromatography-mass spectrometry. The obtained data revealed notable differences between the two groups. The IBD organoids exhibited several alterations at the levels of multiple proteins that are consistent with some known IBD alterations. The observed phenotype in the IBD organoids to some degree mirrors the corresponding intestinal condition, rendering them a compelling approach for investigating the disease and advancing drug exploration. Additionally, our study revealed similarities to some human IBD biomarkers, further emphasizing the translational and comparative value of dogs for future investigations related to the causes and treatment of IBD. Relevant proteins such as CALU, FLNA, MSN and HMGA2, which are related to intestinal diseases, were all upregulated in the IBD duodenal organoids. At the same time, other proteins such as intestinal keratins and the mucosal immunity PIGR were depleted in these IBD organoids. Based on these findings, we propose that these organoids could serve as a valuable tool for evaluating the efficacy of therapeutic interventions against canine IBD.

Faecal microbiota and fatty acids in feline chronic enteropathy

BACKGROUND

Feline chronic enteropathy is a set of disorders defined as the presence of clinical signs of gastrointestinal disease for at least three weeks. The most common final diagnoses are inflammatory bowel disease and alimentary small cell lymphoma. The etiopathogenesis of these diseases is incompletely understood; however, it is hypothesised that they involve a combination of factors, including altered composition and/or functionality of the intestinal microbiome. An important factor in the interplay of the microbiome and host is the production of short- and branched-chain fatty acids.  The aim of this study was to evaluate the possible differences in faecal microbiota diversity, composition and fatty acid production between cats suffering from chronic enteropathy and healthy cats. Sixteen cats suffering from chronic enteropathy and fourteen healthy control cats were enrolled in the study. The microbiota compositions of faecal samples were analysed by using next-generation amplicon sequencing of the V3V4 fragment of the 16S rRNA gene. Fatty acids were evaluated by high-performance liquid chromatography.

RESULTS

Both the alpha and beta diversities were significantly lower in samples obtained from cats with chronic enteropathy. The relative abundance of the phylum Proteobacteria, orders Lactobacillales and Enterobacterales, family Enteriobacteriaceae and genus Escherichia Shigella were higher in diseased cats, whereas the abundance of the phylum Bacteroidota and order Peptococcales were higher in control cats. The faecal concentrations of short-chain fatty acids were higher in cats with chronic enteropathy, with lower propionate proportions and higher butyrate proportions.

CONCLUSION

The study revealed alterations in microbiota compositions and short-chain fatty acid concentration in cats suffering from chronic enteropathy, which is an important finding both for research on the pathogenesis of the disease and for potential therapeutic interventions in the form of faecal microbiota transplantation and/or probiotic supplementation.

Faecal microbiome transplantation improves clinical signs of chronic idiopathic large bowel diarrhoea in working dogs

BACKGROUND

Chronic diarrhoea is a common clinical sign in dogs with chronic enteropathy, and psyllium husk has been shown to improve clinical signs in affected dogs. The aim of this study was to investigate whether faecal microbiome transplant has a similar effect in alleviating clinical signs in dogs with chronic large bowel diarrhoea.

METHOD

Thirty large-breed working dogs with chronic large bowel diarrhoea were divided into a psyllium group (PG) and a faecal microbiome transplant group (FMTG). To the PG, 16 g/day of psyllium husk was administered for 30 days. The FMTG received faecal microbiome transplantation (FMT) once via enema. A daily log of faecal characteristics was kept, and the dogs' canine inflammatory bowel disease index (CIBDAI) and body condition scores (BCS) were determined. A Wilcoxon-Mann-Whitney test was used to compare group results. In addition, the Kaplan-Meier test was used to evaluate the occurrence rate of 1 day or more of diarrhoea and 2 days or more of diarrhoea by day 30.

RESULTS

The sample had a mean age of 3.9 ± 2.1 years and a bodyweight of 25.3 ± 6.8 kg. The FMTG showed a more rapid onset of CIBDAI improvement but no difference in other measures. At 30 days, the FMTG showed a greater improvement in bodyweight and BCS, but no differences were observed in faecal scores, defaecation frequency and time of appearance of episodes of diarrhoea. Time played a significant positive role in the results observed across both groups (p < 0.05).

LIMITATIONS

This study did not compare the microbiomes of the dogs before and after treatment, so the role of specific types of bacteria cannot be determined.

CONCLUSION

Psyllium husk and FMT had similar effects in improving clinical signs of chronic large bowel diarrhoea.

Validation of the fCAL turbo immunoturbidimetric assay for measurement of calprotectin in porcine and bovine fecal samples

The concentration of calprotectin in feces is a well-studied marker of gastrointestinal inflammation in humans. However, little is known about fecal calprotectin in farm animals. In this work, we have validated an immunoturbidimetric method for fecal calprotectin (Bühlmann fCAL® turbo assay, Schönenbuch, Switzerland) in porcine and bovine fecal samples. Linearity was evaluated by serial dilution (R2 > 0.97 was obtained for both species). Accuracy was assessed by a recovery study, with results between 80 and 120% for low, medium, and high samples in both species. Intra- and inter-assay variability was <20%. Limit of detection was 6.4 μg/g in pig and 5.3 μg/g in cow. Limit of quantification was 13.4 μg/g (pig) and 11.1 μg/g (cow). Additionally, clinical validation has been included to evaluate the ability of the assay to detect inflammatory status in the intestine under different management conditions. In experiments with porcine, it was found that piglets treated with ZnO had lower concentrations of fecal calprotectin. In a second experiment in bovine, calves with diarrhea had higher concentration of fecal calprotectin. The Bühlmann fCAL® turbo assay is suitable for measurement of calprotectin in porcine and bovine fecal samples. Moreover, fecal calprotectin could be a good biomarker of intestinal inflammation in both species.

Efficacy of an elemental diet in achieving clinical remission in dogs with chronic enteropathy

BACKGROUND

Diet may induce clinical remission in dogs with chronic enteropathy (CE). Elemental diets (EDs), providing protein as amino acids, modulate intestinal immunity and microbiome in rodents and humans.

HYPOTHESIS

Evaluate the impact of an amino acid-based kibble (EL) on CE clinical activity and gastrointestinal (GI)-relevant variables.

ANIMALS

Client-owned dogs (n = 23) with inadequately controlled CE.

METHODS

Prospective, uncontrolled clinical trial. Diagnostic evaluation including upper and lower GI endoscopy was performed before study entry. Canine chronic enteropathy clinical activity index (CCECAI), serum biomarkers, and fecal microbiome were evaluated before and after 2 weeks of EL. Dogs with stable or improved CE remained in the study for another 6 weeks. Pre- and post-EL clinical and microbiological variables were compared statistically using a mixed model.

RESULTS

After 2 weeks of EL, 15 of 22 dogs (68%; 95% confidence interval [CI], 47%-84%) consuming the diet were classified as responders with a median (range) decrease in CCECAI from 6 (3-12) to 2 (0-9; P < .001). Fourteen of 15 responders and 2/7 nonresponders at 2 weeks completed the trial; all 16 were experiencing adequate control at week 8 with a median CCECAI of 2 (0-3). In total, 16/23 dogs (70%; 95% CI, 49%-84%) were responders. Feeding EL caused shifts in fecal bacterial communities, which differed between responders and nonresponders. Serum biomarker concentrations were unchanged throughout the study apart from serum alkaline phosphatase activity.

CONCLUSIONS

Exclusive feeding of EL improved clinical signs in 16 of 23 dogs with uncontrolled CE. Fecal microbiome shifts were associated with response to diet and may represent a mechanism for clinical improvement.

Pre-illness dietary risk factors in dogs with chronic enteropathy

BACKGROUND

Dietary factors have been extensively studied as potential triggers of inflammatory bowel disease in humans. Scant literature exists regarding diet as a pre-illness risk factor in dogs with chronic enteropathy (CE).

HYPOTHESIS

To evaluate possible pre-illness dietary risk factors in dogs with CE.

ANIMALS

Ninety-five client-owned dogs; 48 with CE (25 presumptive and 23 confirmed) and 47 without a history of signs of gastrointestinal disease.

METHODS

Retrospective case-control questionnaire-based study at a veterinary referral teaching hospital in the United Kingdom. Diet history was obtained relating to the onset of initial presenting signs for all dogs. The main diet consumed underwent ingredient analysis and caloric distribution calculation using a guaranteed analysis convertor software. Length of time the main diet was fed and adherence to the World Small Animal Veterinary Association Global Nutrition Committee guidelines was also recorded.

RESULTS

The frequency of the main diet containing no carbohydrate was greater for controls (5/47 dogs, 11%) vs the combined presumptive and confirmed CE dogs (0/48 dogs, 0%; P = .05). Fewer dogs with confirmed CE were fed a main diet containing red meat as the primary protein source (2/23 dogs, 9%) vs controls (15/47 dogs, 32%; P = .03). A main diet moisture percentage of ≤14% as fed was significantly associated with confirmed CE in logistic regression analysis (OR 5.71 [95% CI: 1.18-27.69]; P = .03).

CONCLUSIONS AND CLINICAL IMPORTANCE

The presence of dietary carbohydrate, protein source, and dietary moisture content, or factors related to moisture content such as preservatives, might play a role as potential pre-illness dietary risk factors in dogs with CE.

Randomized controlled trial of hydrolyzed fish diets in dogs with chronic enteropathy

BACKGROUND

The role of diet in the pathogenesis and treatment of chronic enteropathies (CE) in dogs is unresolved.

OBJECTIVES

To compare the ability of diets composed of hydrolyzed fish, rice starch, and fish oil without (HF) or with prebiotics, turmeric, and high cobalamin (HF+) against a limited ingredient diet containing mixed nonhydrolyzed antigens and oils (control) to resolve clinical signs and maintain serum cobalamin and folate concentrations in dogs with nonprotein losing CE (non-PLE). To determine the ability of hydrolyzed fish diets to support recovery and remission in dogs with PLE.

ANIMALS

Thirty-one client-owned dogs with CE: 23 non-PLE, 8 PLE.

METHODS

Randomized, blinded, controlled trial. Diets were fed for 2 weeks; responders continued for 12 weeks. Nonresponders were crossed over to another diet for 12 weeks. Response was determined by standardized clinical evaluation with long-term follow-up at 26 weeks. Concurrent medications were allowed in PLE.

RESULTS

Nineteen of 23 (83%; 95% confidence interval [CI], 60%-94%) non-PLE CE responded clinically to their initial diet, with no difference between diets (P > .05). Four nonresponders responded to another diet, with sustained remission of 18/18 (100%; 95%CI, 78%-100%) at 26 weeks. Serum cobalamin concentration was increased (P < .05) and maintained by diet. Serum folate concentration decreased posttreatment (P < .05) but was restored by dietary supplementation. Hydrolyzed fish diets supported weight gain, serum albumin concentration, and recovery (P < .05) in dogs with PLE.

CONCLUSIONS AND CLINICAL IMPORTANCE

Changing diet, independent of antigen restriction or supplemental ingredients, induced long-term remission in dogs with non-PLE CE. Serum cobalamin and folate concentrations were maintained by diet. Hydrolyzed fish diets supported clinical recovery and remission in PLE.

Histopathologic diagnosis and patient characteristics in cats with small intestinal obstructions secondary to trichobezoars

OBJECTIVES

The aim of the present study was to describe the distribution of gastrointestinal histopathology findings associated with gastrointestinal obstructions secondary to trichobezoar formation in cats.

METHODS

A total of 100 surgical gastrointestinal biopsies were obtained from 44 cats with gastrointestinal obstructions secondary to a trichobezoar. Medical records, including signalment, type and duration of clinical signs, surgical reports and histopathologic analysis, were reviewed for each cat.

RESULTS

Biopsies taken near the site of the trichobezoar were more likely to show neutrophilic inflammation and mucosal erosion/ulceration compared with biopsies taken elsewhere in the small intestine. Lymphoplasmacytic and mixed lymphocytic and eosinophilic populations were the most common histopathologic findings from all biopsies followed by alimentary small cell lymphoma. Biopsy samples were more likely to represent a diagnosis of alimentary lymphoma in cats older than 10 years.

CONCLUSIONS AND RELEVANCE

Gastrointestinal biopsies taken at the time of surgery in cats with trichobezoar obstructions may represent an important diagnostic tool for further evaluation of potential feline chronic enteropathy. Biopsies taken at the site of the obstruction should be interpreted cautiously as the presence of a trichobezoar may induce an acute inflammatory reaction. The resultant histologic interpretation at this site may not represent the chronic state of the intestinal mucosa, supporting the utility of obtaining multiple biopsies orad and aborad to the obstruction.

Combining ultrasound radiomics, complete blood count, and serum biochemical biomarkers for diagnosing intestinal disorders in cats using machine learning

This retrospective analytical observational cohort study aimed to model and predict the classification of feline intestinal diseases from segmentations of a transverse section from small intestine ultrasound (US) image, complete blood count (CBC), and serum biochemical profile data using a variety of machine-learning approaches. In 149 cats from three institutions, images were obtained from cats with biopsy-confirmed small cell epitheliotropic lymphoma (lymphoma), inflammatory bowel disease (IBD), no pathology ("healthy"), and other conditions (warrant a biopsy for further diagnosis). CBC, blood serum chemistry, small intestinal ultrasound, and small intestinal biopsy were obtained within a 2-week interval. CBC and serum biomarkers and radiomic features were combined for modeling. Four classification schemes were investigated: (1) normal versus abnormal; (2) warranting or not warranting a biopsy; (3) lymphoma, IBD, healthy, or other conditions; and (4) lymphoma, IBD, or other conditions. Two feature selection methods were used to identify the top 3, 5, 10, and 20 features, and six machine learning models were trained. The average (95% CI) performance of models for all combinations of features, numbers of features, and types of classifiers was 0.886 (0.871-0.912) for Model 1 (normal vs. abnormal), 0.751 (0.735-0.818) for Model 2 (biopsy vs. no biopsy), 0.504 (0.450-0.556) for Model 3 (lymphoma, IBD, healthy, or other), and 0.531 (0.426-0.589), for Model 4 (lymphoma, IBD, or other). Our findings suggest model accuracies above 0.85 can be achieved in Model 1 and 2, and that including CBC and biochemistry data with US radiomics data did not significantly improve accuracy in our models.

Fecal acute phase proteins in cats with chronic enteropathies

BACKGROUND

Chronic enteropathies (CE) are common in cats and reliable biomarkers that can distinguish different causes and predict or monitor response to treatment are currently lacking.

HYPOTHESIS

To evaluate certain acute phase proteins in feces that could potentially be used as biomarkers in cats with CE.

ANIMALS

Twenty-eight cats with either inflammatory bowel disease (IBD; n = 13), food-responsive enteropathy (FRE; n = 3) or small cell gastrointestinal lymphoma (SCGL; n = 12) and 29 healthy control cats were prospectively enrolled.

METHODS

Fecal concentrations of haptoglobin, alpha-1-acid-glycoprotein (AGP), pancreatitis-associated protein-1 (PAP-1), ceruloplasmin, and C-reactive protein (CRP) were measured using Spatial Proximity Analyte Reagent Capture Luminescence (SPARCL) immunoassays before and after initiation of treatment. Cats were treated with diet and/or prednisolone (IBD cats), plus chlorambucil (SCGL cats).

RESULTS

Compared with controls, median fecal AGP concentrations were significantly lower (25.1 vs 1.8 μg/g; P = .003) and median fecal haptoglobin (0.17 vs 0.5 μg/g), PAP-1 (0.04 vs 0.4 μg/g) and ceruloplasmin (0.15 vs 4.2 μg/g) concentrations were significantly higher (P < .001) in cats with CE. Median fecal AGP concentrations were significantly lower (P = .01) in cats with IBD and FRE (0.6 μg/g) compared with cats with SCGL (10.75 μg/g). A significant reduction was found in CE cats after treatment for median fecal ceruloplasmin concentrations (6.36 vs 1.16 μg/g; P = .04).

CONCLUSIONS

Fecal AGP concentration shows promise to differentiate cats with SCGL from cats with IBD and FRE. Fecal ceruloplasmin concentrations may be useful to objectively monitor response to treatment in cats with CE.

Serum proteome profiles in cats with chronic enteropathies

BACKGROUND

Serum protein biomarkers are used to diagnose, monitor treatment response, and to differentiate various forms of chronic enteropathies (CE) in humans. The utility of liquid biopsy proteomic approaches has not been examined in cats.

HYPOTHESIS/OBJECTIVES

To explore the serum proteome in cats to identify markers differentiating healthy cats from cats with CE.

ANIMALS

Ten cats with CE with signs of gastrointestinal disease of at least 3 weeks duration, and biopsy-confirmed diagnoses, with or without treatment and 19 healthy cats were included.

METHODS

Cross-sectional, multicenter, exploratory study with cases recruited from 3 veterinary hospitals between May 2019 and November 2020. Serum samples were analyzed and evaluated using mass spectrometry-based proteomic techniques.

RESULTS

Twenty-six proteins were significantly (P < .02, ≥5-fold change in abundance) differentially expressed between cats with CE and controls. Thrombospondin-1 (THBS1) was identified with >50-fold increase in abundance in cats with CE (P < 0.001) compared to healthy cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

Damage to the gut lining released marker proteins of chronic inflammation that were detectable in serum samples of cats. This early-stage exploratory study strongly supports THBS1 as a candidate biomarker for chronic inflammatory enteropathy in cats.

Prognostic value of increased intraepithelial lymphocytes and lymphocytic clonality in dogs with chronic enteropathy or small-cell lymphoma

The clinical significance of severe infiltration of small intraepithelial lymphocytes (IEL) and the results of polymerase chain reaction for antigen receptor rearrangement (PARR) in dogs with chronic enteropathy (CE) and small-cell lymphoma (SCL) are controversial. This cohort study aimed to evaluate the prognostic significance of the IEL and PARR results in dogs with CE or SCL. Although definitive diagnostic histopathological criteria for SCL in dogs have yet to be established, dogs with the histopathological findings of severe IEL infiltration were diagnosed with SCL in this study. One hundred and nineteen dogs were recruited, with 23 dogs classified as having SCL and 96 dogs as having CE. The positive rate of PARR was 59.6 % (71/119) in the duodenum and 57.7 % (64/111) in the ileum. Subsequently, three dogs with SCL and four dogs with CE developed large-cell lymphoma (LCL). The median overall survival (OS) of dogs with SCL was 700 days (range, 6-1410 days), and that of dogs with CE was not reached. In the log-rank test, shorter OS was observed in cases with histopathological SCL (P = 0.035), clonal TCRγ rearrangement in the duodenum (P = 0.012), and clonal IgH rearrangement in the ileum (P < 0.0001). The Cox proportional hazards model adjusted for sex and age showed that histopathological SCL (hazard ratio [HR] 1.74; 95 % confidence interval [CI], 0.83-3.65), duodenal clonal TCRγ rearrangement (HR, 1.80; 95 % CI, 0.86-3.75), and ileal clonal IgH rearrangement (HR, 2.28; 95 % CI, 0.92-5.70) could shorten overall survival, although their 95 % CIs included 1.0. These results indicate that severe IEL infiltration could be a useful histopathological feature for diagnosing SCL, and clonality-positive results could be a negative prognostic factor in dogs with CE. Furthermore, the development of LCL should be carefully monitored in dogs with CE and SCL..

ACVIM consensus statement guidelines on diagnosing and distinguishing low-grade neoplastic from inflammatory lymphocytic chronic enteropathies in cats

BACKGROUND

Lymphoplasmacytic enteritis (LPE) and low-grade intestinal T cell lymphoma (LGITL) are common diseases in older cats, but their diagnosis and differentiation remain challenging.

OBJECTIVES

To summarize the current literature on etiopathogenesis and diagnosis of LPE and LGITL in cats and provide guidance on the differentiation between LPE and LGITL in cats. To provide statements established using evidence-based approaches or where such evidence is lacking, statements based on consensus of experts in the field.

ANIMALS

None.

METHODS

A panel of 6 experts in the field (2 internists, 1 radiologist, 1 anatomic pathologist, 1 clonality expert, 1 oncologist) with the support of a human medical immunologist, was formed to assess and summarize evidence in the peer-reviewed literature and complement it with consensus recommendations.

RESULTS

Despite increasing interest on the topic for clinicians and pathologists, few prospective studies were available, and interpretation of the pertinent literature often was challenging because of the heterogeneity of the cases. Most recommendations by the panel were supported by a moderate or low level of evidence. Several understudied areas were identified, including cellular markers using immunohistochemistry, genomics, and transcriptomic studies.

CONCLUSIONS AND CLINICAL IMPORTANCE

To date, no single diagnostic criterion or known biomarker reliably differentiates inflammatory lesions from neoplastic lymphoproliferations in the intestinal tract of cats and a diagnosis currently is established by integrating all available clinical and diagnostic data. Histopathology remains the mainstay to better differentiate LPE from LGITL in cats with chronic enteropathy.