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.

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.

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.

Successful management of histiocytic ulcerative colitis with enrofloxacin in two Boxer dogs

Two Boxer dogs with histologically confirmed histiocytic ulcerative colitis were treated with enrofloxacin, one as sole therapy and one in conjunction with prednisolone, after failure of standard therapy. Clinical remission occurred rapidly in both dogs after commencement of enrofloxacin and in one case where repeat colonoscopy was performed the endoscopic appearance of the mucosa was normal within 2 weeks. Histological examination of the colonic mucosa in this dog after 7 months showed resolution of the cellular infiltration characteristic of histiocytic ulcerative colitis. Histological improvement following therapy in Boxer dogs with histiocytic ulcerative colitis has not been reported previously.

Histiocytic ulcerative colitis in a French bulldog

A 9-month-old French bulldog was referred for signs of chronic large bowel diarrhea. The dog had an increased frequency of defecation, tenesmus and hematochezia. Flexible colonoscopy showed hyperemia, irregularities and ulcerations with multifocal hemorrhages in the mucosa from the descending colon to the proximal rectum. Multiple colonic biopsies were characterized by infiltrations of PAS positive histiocytes in the lamina propria. A diagnosis of histiocytic ulcerative colitis (HUC) was made, and the animal showed only minimal improvement, although it was treated with nutritional and medical therapies. This is the second case of HUC in French bulldog, a breed which has ancestral relations to Boxer dogs.

Canine histiocytic ulcerative colitis

OBJECTIVE

To assess prevalence, breed predilection, response to therapy and prognosis of canine histiocytic ulcerative colitis (CHUC).

DESIGN

A retrospective study of cases of CHUC seen at Sydney University Veterinary Teaching Hospital (SUVTH) over a 20-year period (1975-1994).

PROCEDURE

Case records of all dogs in which colitis was suspected were reviewed. Dogs were diagnosed with CHUC based on colonorectal biopsy and histopathological examination.

RESULTS

CHUC was diagnosed in 8 of 57 dogs presented for colitis. All affected dogs were Boxers and six were female. Dogs with milder clinical signs showed moderately good response to therapy. Four dogs were still alive 1 to 7 years after diagnosis. Three dogs were euthanased, one for reasons other than CHUC, and one was lost to follow-up.

CONCLUSIONS

Young boxer dogs with relatively mild signs of CHUC may respond moderately well to medical and dietary therapy with fair prognosis. Euthanasia early in the course of the disease may be unwarranted. Prevalence may be increasing within the SUVTH referral population.

Regional eosinophilic coloproctitis, typhlitis and ileitis in a dog

A 3-year-old female Petit Basset Griffon Vendeen is presented with tenesmus alvi caused by a 15 cm long chronic regional cicatrising eosinophilic coloproctitis with bacterial masses surrounded by clubs, resembling actinomycosis. Similar changes were found in the caecum, next to a nodular eosinophilic inflammation in the ileal mucosa.