Tristan Méric

Background: T lymphocytes play a central role in the intestinal immune response in dogs with immunomodulator-responsive enteropathy (IRE), but the clinical relevance of mucosal T-cell infiltration remains unclear. Hypothesis/Objectives: Compare mucosal CD3+ T-cell density between dogs with IRE and healthy comparison dogs across intestinal segments, and assess associations with clinical, biochemical, and histologic severity markers. Animals: Forty-two client-owned dogs with IRE and 12 healthy research dogs. Methods: Retrospective multicenter study. Archived endoscopic biopsy samples from the duodenum, ileum, and colon were evaluated using the Simplified Histopathological Scoring System. Immunohistochemistry for CD3 was quantified by digital image analysis (QuPath) and expressed as relative CD3+ density (RCD3). Group comparisons, receiver operating characteristic curve analyses, mixed linear models, and correlation analyses were performed. Results: Relative CD3+ density was significantly higher in dogs with IRE than in comparison dogs in the duodenum (median, 6.34% vs 1.42%; P = .03), ileum (9.79% vs 0.85%; P < .001), and colon (3.88% vs 1.32%; P = .002). The area under the curve values were 0.833, 0.896, and 0.811, respectively. The RCD3 was not correlated with clinical indices, serum albumin concentration, or histologic scores, but ileal histologic score was negatively correlated with RCD3 (ρ = −0.37; P = .04). Conclusions and clinical importance: Mucosal CD3+ T-cell density is increased in dogs with IRE but is not associated with clinical or overall histologic disease severity. Quantification of CD3+ should not be used as a solitary monitoring tool but may contribute to immunophenotyping.

Rethinking response criteria of treatment of chronic enteropathy in dog is necessary, as clinical activity indices are widely used as primary endpoints despite substantial variability in how “response,” “remission,” and “relapse” are defined. Across recent studies, response thresholds range from modest relative reductions (eg, ≥25%) to stringent targets (eg, ≥75%), absolute score cut-offs, shifts between severity categories, or binary resolution of clinical signs. This methodological heterogeneity undermines comparability between trials and complicates evidence synthesis. An often-overlooked contributor to this issue is the intrinsic variability of the Canine Inflammatory Bowel Disease Activity Index and the Canine Chronic Enteropathy Clinical Activity Index, particularly their limited inter-observer reproducibility for total scores and several core items. When commonly used response thresholds overlap with expected measurement error, apparent clinical improvement might reflect scoring variability rather than true change in disease activity. We therefore propose a pragmatic framework for response classification anchored in the measurement properties of these instruments. For research endpoints, an absolute change of at least 4 points (Δ ≥ 4) is suggested as a conservative minimal detectable change to reduce misclassification of responders and non-responders. In dogs with low baseline scores driven by 1 or 2 isolated abnormalities, an item-centered approach (Δ item ≥2) might be more appropriate, particularly for variables such as stool consistency or defecation frequency. Finally, transparent reporting of scoring conditions, prioritization of evaluator consistency, and integration of complementary outcomes, including validated health-related quality-of-life measures and longitudinal symptom tracking, might help better capture clinically meaningful effects.

Chronic inflammatory enteropathies (CIEs) in dogs are currently classified based on response to sequential treatment trials into food-responsive (FREs); antibiotic-responsive (AREs); immunosuppressant-responsive (IREs); and non-responsive enteropathies (NREs). Recent studies have reported that a proportion of NRE dogs ultimately respond to further dietary trials and are subsequently misclassified. The FRE subset among CIEs is therefore probably underestimated. Moreover, alterations in the gut microbiota composition and function (dysbiosis) have been shown to be involved in CIE pathogenesis in recent research on dogs. Metronidazole and other antibiotics that have been used for decades for dogs with AREs have been demonstrated to result in increased antimicrobial resistance and deleterious effects on the gut microbiota. As a consequence, the clinical approach to CIEs has evolved in recent years toward the gradual abandonment of the use of antibiotics and their replacement by other treatments with the aim of restoring a diverse and functional gut microbiota. We propose here to refine the classification of canine CIEs by replacing the AREs category with a microbiota-related modulation-responsive enteropathies (MrMREs) category.

Le microbiote digestif est impliqué dans la pathogénie de nombreuses maladies digestives, aiguës ou chroniques. Dès lors, la dysbiose associée à ces entéropathies devient une cible thérapeutique. Les probiotiques sont des micro-organismes vivants aux combinaisons variées, dont certaines ont fait l’objet d’essais cliniques. L’état des preuves du bénéfice des probiotiques est globalement faible, mais des indications accumulent des conclusions concordantes de quelques publications. Parmi les maladies digestives aiguës, les probiotiques multi-souches contenant des Lactobacillus et des Bifidobacterium semblent bénéfiques pour les diarrhées bénignes sans cause identifiée (preuves moyennes à suffisantes), et les probiotiques contenant notamment un Enterococcus faecium semblent diminuer le risque de signes digestifs parmi les animaux hébergés en chenil (preuves moyennes). Parmi les maladies digestives chroniques, les probiotiques multi-souches contenant des Lactobacillus et des Bifidobacterium semblent bénéfiques pour les entéropathies inflammatoires idiopathiques (preuves moyennes). Les preuves restent faibles pour les signes digestifs associés à la prise d’antibiotique, la parvovirose, les dysmotilités coliques non-inflammatoires et les signes digestifs induits par une chimiothérapie multi-médicamenteuse (lymphome multicentrique).

Background: Compared to humans, colorectal polyps are relatively rare in dogs. Epidemiological and prognostic data remain accordingly sparse, although they could help veterinary clinicians in the management of these cases. Objectives: To report the epidemiological data of dogs with colorectal polyps and identify factors associated with recurrence and survival. Animals: Fifty-eight client-owned dogs with colorectal polyps admitted to 7 veterinary hospitals (53 dogs from France, 5 dogs from Spain, and 4 dogs from Portugal) were included. Methods: Retrospective multicentric cohort study. Medical records and long-term outcome of the dogs were reviewed. When available, histological samples were reassessed by 2 board-certified pathologists according to the revised Vienna classification (RVC). Results: The West Highland White Terrier (WHWT) breed was significantly associated with the presence of colorectal polyps (OR: 20; 95% CI: 7.5-52; P < .001). The overall median time to recurrence was not reached after 2000 days. The overall estimated median survival time was 1640 days. WHWT breed and larger polyps were significantly associated with a shorter time of polyp recurrence after surgical removal (respectively, P = .05 and P = .01). Conclusions and Clinical Importance: The probability of recurrence of colorectal polyps in dogs is low, but increased in WHWTs and larger polyps, which might benefit from routine screening after removal. No effective predictors of polyp recurrence and survival were identified using the RVC.