Association between Granulomatous Colitis in French Bulldogs and Invasive Escherichia coli and Response to Fluoroquinolone Antimicrobials

Abstract

Background French Bulldogs develop a form of granulomatous colitis (GC) with histopathological resemblance to GC of Boxer dogs (GCB). GCB is associated with mucosally invasive Escherichia coli whose eradication correlates with clinical remission. Hypothesis/Objectives To characterize the clinical and histopathological features, presence or absence of invasive colonic bacteria, and response to fluoroquinolones in French Bulldogs with GC. Animals A total of 6 French Bulldogs with a histological diagnosis of GC. Methods Retrospective study of medical records. Bacterial colonization was evaluated using 16S rRNA probes for eubacteria and E. coli. Biopsy specimens from 3 dogs were cultured for bacteria. Clinical response to fluoroquinolone antimicrobials was determined. Results All dogs were ≤1 year of age with hematochezia that was refractory to empirical therapy. Clinicopathologic and fecal analysis did not reveal abnormalities. Abdominal ultrasound revealed patchy thickening of the colon in 4/5 dogs and regional lymphadenopathy in 5/5. Colonoscopic abnormalities included irregularly thickened and ulcerated mucosa, hyperemia, and overt bleeding in 4/6 cases. Multifocal accumulations of PAS‐positive macrophages and intramucosal E. coli were present in colonic biopsies of all 6 dogs. Administration of enrofloxacin (5/6) or marbofloxacin (1/6) at 4.4–10 mg/kg (median 10 mg/kg) PO q24h for 6–10 weeks was associated with clinical improvement within 5–14 days. All dogs remained in remission over a 3–30 month follow‐up period. Conclusions Granulomatous colitis in young French Bulldogs is associated with the presence of invasive E. coli and closely parallels GCB. Treatment with fluoroquinolone antimicrobials can induce lasting clinical remission.

Granulomatous colitis in two French bulldogs unresponsive to fluoroquinolone antimicrobials: a case report

“…It has also been reported in the Mastiff , Alaskan malamute, Doberman pinscher, English bulldog (Manchester et al 2013) and Beagle (Carvallo et al 2015). Young dogs are predominantly aff ected with clinical signs which are similar to those observed in other forms of chronic colitis (Sherding 2003).…”

“…GC is a severe chronic disease mostly seen in Boxer dogs (Mansfi eld et al 2009;Craven et al 2010) and French bulldogs (Van der Gaag et al 1978;Tanaka et al 2003;Manchester et al 2013). It has also been reported in the Mastiff , Alaskan malamute, Doberman pinscher, English bulldog (Manchester et al 2013) and Beagle (Carvallo et al 2015).…”

“…In the past, most GC cases failed to respond to any therapy. However, since the association between GC and E. coli strains within the colonic mucosa in affected dogs was reported, the condition has been successfully managed with enrofloxacin therapy (Mansfield et al 2009;Craven et al 2010;Lechowski et al 2013;Manchester et al 2013). The aim of this study was to describe two cases of GC in French bulldogs that failed to respond to any fluoroquinolone therapy.…”

“…Clinical signs include chronic diarrhoea with increasing frequency of defecation, haematochezia, mucus and tenesmus (Stokes et al 2001;Hostutler et al 2004;Craven et al 2010;Manchester et al 2013). Severe cases also exhibit hypoalbuminemia and cachexia (Manchester et al 2013). In the past, most GC cases failed to respond to any therapy.…”

“…Granulomatous colitis (GC), also known as histiocytic ulcerative colitis, is a chronic inflammation of the colonic mucosa seen in young Boxer dogs (Davis et al 2004;Craven et al 2010;Manchester et al 2013) and in French bulldogs, a breed ancestrally related to Boxer dogs ( Van der Gaag et al 1978;Tanaka et al 2003;Manchester et al 2013). Clinical signs include chronic diarrhoea with increasing frequency of defecation, haematochezia, mucus and tenesmus (Stokes et al 2001;Hostutler et al 2004;Craven et al 2010;Manchester et al 2013).…”