Histiocytic ulcerative colitis in a French bulldog

Use of Contrast-Enhanced Ultrasonography and Shear-Wave Elastography in the Diagnosis of Granulomatous Colitis in a French Bulldog

An 11-month-old male intact French Bulldog was referred for chronic intermittent diarrhea lasting three months. Ultrasonographic (US) examination revealed severe thickening of the wall of the colon and caecum; contrast-enhanced US (CEUS) and elastography showed increased, heterogeneous vascularization and non-uniform stiffness of the colonic wall. The mucosa was thickened, fragile, and ulcerated as revealed by endoscopy, and histological examination confirmed the suspicion of granulomatous colitis.

[Granulomatous colitis in a French Bulldog puppy]

A 6-month-old French bulldog was presented due to chronic large intestinal diarrhea of 4 months duration. The diagnostic procedures initiated by the referring veterinarian had resulted in a tentative diagnosis of chronic enteropathy, however treatment consisting of elimination diet as well as antibiotic, anthelmintic, anti-inflammatory and immunosuppressive medication had been unsuccessful. By means of endoscopy and histological examination, pronounced erosions and ulcerations of the colonic mucosa were detected. Fluorescence in situ hybridization enabled the identification of invasive Escherichia coli within the colonic mucosa and colonic macrophages, allowing for the diagnosis of granulomatous colitis. The dog showed complete remission of clinical signs following 8 weeks of treatment with enrofloxacin. This case report describes the first successful treatment of granulomatous colitis with enrofloxacin in a French bulldog puppy in Germany and is intended to sensitize the reader to this disease in (young) dogs.

Clinical characteristics and long-term outcome of E. coli-associated granulomatous ileocolitis in dogs: five cases (2010-2014)

OBJECTIVES

To describe the clinical characteristics and long-term outcome of Escherichia coli-associated granulomatous ileocolitis in dogs.

METHODS

Retrospective review of medical records from dogs with periodic acid-Schiff positive (PAS+) granulomatous ileocolitis and mucosally invasive E. coli in the ileum and colon. Initial bacterial colonisation was evaluated using fluorescence in situ hybridization (FISH) in all dogs and corroborated with colonic and/or ileal culture, when performed.

RESULTS

Four boxer dogs and 1 French Bulldog with PAS+ granulomatous ileocolitis (GIC) were evaluated. All dogs had chronic diarrhoea refractory to empirical therapy. Ileocolonoscopy revealed mucosal haemorrhage and ulceration in the ileum (3/4) and colon (5/5). E. coli were visualised as clusters within the ileal and colonic mucosa. Complete (CR, 4/5) or partial (PR, 1/5) clinical response to fluoroquinolones was noted in all dogs within 30 days. CR was sustained in three of four dogs (median disease-free interval 40 months, range 16 to 60). Two dogs relapsed while receiving fluoroquinolones. Repeat biopsy isolated multidrug-resistant, mucosally invasive E. coli in the ileum (1/2) and colon (2/2). Targeted antimicrobial therapy was associated with long-term PR (78 months) in both dogs.

CLINICAL SIGNIFICANCE

Concurrent E. coli-associated granulomatous inflammation in the ileum and colon did not impart a poor clinical outcome or lack of response to the conventional standard of care for granulomatous colitis in dogs that were aggressively diagnosed and treated. Clinical outcome was influenced by antimicrobial resistance, with response dependent upon antimicrobial therapy informed by susceptibility testing.

Endoscopic Biopsies and Histopathological Findings in Diagnosing Chronic Gastrointestinal Disorders in Dogs and Cats

Nowadays, endoscopic examination is a diagnostic tool gaining popularity in the management of gastrointestinal disorders in dogs and cats. Direct accessibility of the lumen of gastrointestinal tract combined with the mucosal biopsy provides a great diagnostic potential. Using endoscopy and endoscopically guided biopsy, one can conduct both macro- and microscopic assessment of lesions and perform many specialist adjunct examinations. Histopathological examination of mucosal biopsy specimens collected from the stomach and intestines allows us to distinguish between types of inflammations and to diagnose ulcerative, polypoid, and cancerous lesions.

Escherichia coli-induced granulomatous colitis in a cat

Case summary

A 10-year-old castrated male domestic shorthair cat presented with a 6 month history of diarrhoea that responded poorly to medical treatment. Ultrasonography revealed moderate thickening of the colonic wall (4.8 mm) and right colic and jejunal lymphadenomegalies. Endoscopic examination revealed partial circumferential narrowing of the transverse colon and friable colonic mucosa with multiple haemorrhagic regions. Histopathological and immunohistochemical examinations revealed a large number of Escherichia coli phagocytosed by periodic acid–Schiff-positive macrophages. Bacterial culture also yielded enrofloxacin-sensitive E coli. The cat was initially treated with prednisolone, which resulted in little improvement. Following histopathological examination and bacterial culture, treatment with enrofloxacin was commenced. Antibacterial therapy resulted in remission of the diarrhoea and an increase in body weight within 14 days.

Relevance and novel information

Granulomatous colitis (GC) or histiocytic ulcerative colitis has been rarely described in cats. There has only been one previously published case study involving a cat, and the aetiology remains largely unknown. The current article describes the regression of E coli-related GC following antibacterial treatment in a cat. Clinical signs, histopathological appearance and response to enrofloxacin were similar to those in canine GC. The current findings suggest that E coli also plays an important role in the development of feline GC.

Heterogeneity of macrophages in canine histiocytic ulcerative colitis

Histiocytic ulcerative colitis (HUC) is a chronic enteropathy which most notably occurs in Boxer dogs and French bulldogs. The inflamed mucosa is hallmarked by large, foamy, periodic acid–Schiff (PAS)-positive macrophages infiltrating the colonic mucosa. As little is known about their origin and phenotype, an immunohistochemical study was performed using different macrophage markers. Generally, canine colonic macrophages showed high expression of ionised calcium-binding adaptor molecule 1 and MHC class II. In canine HUC, macrophages revealed up-regulation of lysozyme and L1 Ag but decreased CD163 expression compared with controls, suggesting them to be pro-inflammatory cells, whereas the healthy colonic mucosa was characterised by an anti-inflammatory macrophage phenotype. In addition, PAS reaction was used to discriminate macrophage subpopulations. PAS– macrophages displayed higher expression of L1 Ag and CD64, whereas PAS+ cells, which were only present in HUC patients, were characterised by increased expression of lysozyme, inducible nitric oxide synthase and CD204. This indicates PAS+ cells to be mature macrophages contributing to the inflammatory process, which are most likely maintained by differentiation of immature PAS– macrophages continuously recruited from blood monocytes. In summary, macrophage heterogeneity in canine HUC probably illustrates their different maturation states and functions compared with the healthy animals.

Proper use of Quinolones for canine colitis ambulatory treatment: literature review and REQUEST guidelines

The literature analysed by REQUEST (REassesing QUinolone European STandard) using inclusion and exclusion criteria allows to make the conclusion that the proper use of fluoroquinolones (FQ) in canine colitis requires rigorously performed qualification to specific antimicrobial treatment. An infectious agent responsive to FQ therapy plays an integral role in the clinical manifestation of canine colitis, especially histiocytic ulcerative colitis (HUC) in young Boxer dogs. This supports the use of FQ in these cases. The Request guidelines for proper use of FQ in canine colitis is established, according to the available literature data.

Association between granulomatous colitis in French Bulldogs and invasive Escherichia coli and response to fluoroquinolone antimicrobials

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.

Pitfalls and progress in the diagnosis and management of canine inflammatory bowel disease

Inflammatory bowel disease (IBD) is the collective term for a group of chronic enteropathies characterized by persistent or recurrent gastrointestinal (GI) signs and inflammation of the GI tract. The specific steps that lead to IBD and the basis for phenotypic variation and unpredictable responses to treatment are not known. This article examines IBD in dogs, focusing on the interaction between genetic susceptibility and the enteric microenvironment (bacteria, diet), the utility of recently developed histologic criteria, the prognostic indicators, and the standardized approaches to treatment.

Granulomatous colitis of boxer dogs

Granulomatous colitis (GC) is a rare, breed-specific inflammatory bowel disease of young Boxer dogs. GC has been refractory to treatment and associated with high mortality rates, but culture-independent molecular analysis has transformed therapy and prognosis by uncovering a correlation between GC and Escherichia coli invasion within colonic mucosal macrophages. GC-associated invasive E coli are similar to a newly identified E coli pathotype, "adherent and invasive E coli," that are increasingly associated with Crohn's disease in humans. Successful treatment of GC requires antimicrobials that are effective against E coli and penetrate intracellularly. Enrofloxacin is widely regarded as the antibiotic of choice.