Antibiotic‐Responsive Histiocytic Ulcerative Colitis in 9 Dogs

Abstract

Canine histiocytic ulcerative colitis (HUC) is characterized by colonic inflammation with predominantly periodic acid-Schiff (PAS)-positive macrophages. The inflammation results in colonic thickening, ulcerations, and distortion of normal glandular architecture. Resultant clinical signs consist of chronic large bowel diarrhea, tenesmus, and marked weight loss, and the disease frequently results in euthanasia. Conventional therapy consists of some combination of prednisone, azathioprine, sulfasalazine, and metronidazole. Nine dogs (8 Boxers and 1 English Bulldog) with histologic confirmation of HUC were treated with antibiotic therapy (either with enrofloxacin alone or in combination with metronidazole and amoxicillin). Clinical signs, physical examination findings, laboratory abnormalities, and the histologic severity of the disease were evaluated. Four of the 9 dogs had been treated previously with conventional therapy and had failed to respond favorably; then, these dogs were placed on antibiotic therapy (enrofloxacin, n ϭ 1; enrofloxacin, metronidazole, and amoxicillin, n ϭ 3) and had resolution of clinical signs within 3-12 days. Five dogs were treated solely with antibiotic therapy (enrofloxacin, n ϭ 1; enrofloxacin and metronidazole, n ϭ 1; enrofloxacin, metronidazole, and amoxicillin, n ϭ 3), and clinical signs resolved in 2-7 days. Repeated biopsy specimens were obtained from 5 dogs after treatment, and all showed marked histologic improvement. The increase in body weight after treatment was statistically significant (P ϭ .01). Three dogs currently are not on any treatment and have had resolution of clinical signs for up to 14 months. These observations suggest that an infectious agent responsive to antibiotics plays an integral role in the clinical manifestation of canine HUC, and they support the use of antibiotics in its treatment.

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

“…Young dogs are predominantly aff ected with clinical signs which are similar to those observed in other forms of chronic colitis (Sherding 2003). Th e defi nitive GC diagnosis is made on the basis of PAS-positive histiocytes in the lamina propria of the colonic mucosa (Tanaka et al 2003;Hostutler et al 2004;Mansfi eld et al 2009;Craven et al 2010). Th e cause of GC is not still clear.…”

“…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).…”

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

“…However, although HUC displays a higher predisposition in Boxers (Hill and Sulivan 1978, German et al 2000, Davies et al 2004, Mansfielt et al 2009) it has also been described in other breeds, such as French buldog, Doberman pincher, Mastiff and Alaskan malamute (Stokes et al 2001, Tanaka et al 2003, Hostutler et al 2004, Cerquetella et al 2010). …”

“…The papers of Hostutler et al (2004) and Mansfielt et al (2009) show that Boxer's HUC is the main indication for use of antimicrobials among which the FQ are the most appreciated. An infectious agent responsive to FQ therapy plays an integral role in the clinical manifestation of canine colitis, especially HUC and supports the use of FQ (Hansen et al 2010).…”

“…Dogs with colitis are treated preferentially per os, less frequently parenterally. Enrofloxacin is the main FQ described in the literature (Hill and Sulivan 1978, Davies et al 2004, Hostutler et al 2004) and both oral and subcutaneous route of administration are acceptable with high degree of bioaviability It has been concluded, using an animal model of colitis (rat, mouse), that one of the FQ -ciprofloxacin -is effective against bacterial colitis especially against Gram-negative microorganisms (Cummings et al 2003). However ciprofloxacin when combined with metronidazole and clindamycin is most consistently effective if given before the onset of colitis (Cummings et al 2003).…”