(GI29) Diagnosis and Therapeutic Response of Chronic Colitis in French Bulldogs

Abstract: Background - Granulomatous colitis (GC) is a chronic enteropathy caused by adherent-invasive strains of E. coli (AIEC) which French bulldogs (FB) have a high predisposition. Although, other causes of colitis may cause the same signs. Objective- To compare the clinical and histopathological aspects of FB with chronic diarrhea Animals- Paraffin blocks selected from 38 FB referred to the veterinary gastroenterology service in São Paulo Brazil, with chronic diarrhea, from 2014 to 2022. Four animals were excluded due poor quality of biopsies and other five were excluded for absence of medical records. Methods- Retrospective analysis of medical records was crossed with a blinded evaluation of hematoxylin-eosin, periodic acid–Schiff (PAS) and immunohistochemistry (IHC) for E. coli. by certified veterinary pathologist. Statistical test was used to investigate difference between GC and NGC. Results- GC was identified in 38.2% (13/34) of FB and 61.8% (21/34) were considered Non-GC (NGC): 32.4% had eosinophilic/ neutrophilic (NE), 17.6% NI (no inflammatory) and 11.8% LP (lymphoplasmacytic). Average age was 1.3 years in GC (76.9% males) group, and 2.8 years in NGC group (76.2% males). No statistical difference between groups. All animals received drug treatment prior to biopsy, 79.3% antibiotic (n=23) and 48.0% corticosteroid (n=14). GC dogs had 20 times more chance to present daily diarrhea them NGCs (OR 20.0 [CI 95%:3.1; P< 0.0043). Conclusions- Daily diarrhea is a high indicator of GC in FB with chronic diarrhea. Although diagnosis require a colon biopsy with PAS and IHC stains to determine the presence of AIEC in the mucosa.