A Retrospective Study of Inflammatory Colorectal Polyps in Miniature Dachshunds

Abstract

ABSTRACT. Medical records of dogs with colorectal polyps were retrospectively reviewed, and clinical presentation of inflammatory colorectal polyps in miniature dachshunds was evaluated. Of 33 dogs found to have colorectal polyps, miniature dachshunds were markedly over-represented with 16 dogs (48%), of which 12 (75%) were found to have inflammatory polyps. Multiple polyps localized between the rectum and the descending colon was the most common finding in miniature dachshunds with inflammatory polyps. Twenty dogs (80%) out of 25 miniature dachshunds with inflammatory colorectal polyps responded to immunosuppressive therapy using prednisolone and cyclosporine. The results of this study indicate that miniature dachshunds are predisposed to develop inflammatory colorectal multiple polyps, for which immunosuppressive therapy may be a treatment option. Polyps are an abnormal growth of tissue arising from the mucosa, including neoplasms and inflammatory polyps. In dogs, colorectal polyps are relatively common in the gastrointestinal tract. These polyps can be single or multiple and are most often located in the distal rectum, causing the common clinical signs of hematochezia or tenesmus. In previous reports, many colorectal polyps in dogs were found to be derived from neoplasms, with adenomatous polyps and adenocarcinoma being most frequently represented [11,25,32,33]. Adenomatous polyps and adenocarcinoma are observed as solitary masses in the rectum, and most polyps appear as friable, lobulated, sessile, or pedunculated lesions on the mucosa. Surgical resection has been recommended in dogs as treatment for colorectal polyps [2,5,21]. Endoscopic treatment for adenomatous polyps [7,10] and piroxicam for tubulopapillary polyps [15] have been reported as alternative therapies for colorectal neoplasms. On the contrary, inflammatory colorectal polyps are rare, and few reports have described the clinical features of inflammatory colorectal polyps [33]. In humans, inflammatory colorectal polyps or polypoid lesions occur in association with inflammatory bowel disease (IBD) and other inflammatory diseases of the colon such as ischemic or infective colitis [3,17,24]. These masses form mainly due to extensive mucosal damage and healing processes, rather than infiltration of inflammatory cells. The polyps formed from infiltration of inflammatory cells, which could be termed "true" inflammatory polyps, seem to be relatively rare in humans.This study was conducted on the basis of two objectives. First, we retrospectively investigated dogs with colorectal polyps to characterize the prevalence and clinical features of the disease in Japan. Second, we reviewed the clinical presentation and treatment response of cases with inflammatory colorectal multiple polyps in miniature dachshunds, which were markedly over-represented in our study. MATERIALS AND METHODS Retrospective study of colorectal polyps in dogs:We reviewed the medical records of 33 dogs found to have colorectal polyps at the Veterinary Medical Center of the University of...

Polypoid Adenomas Secondary to Inflammatory Colorectal Polyps in 2 Miniature Dachshunds

“…However, in some cases, immunosuppressive treatment results in a poor therapeutic response, ultimately requiring surgical removal. We previously reported that 1 of the 30 dogs included in a retrospective study developed adenoma during immunosuppressive therapy [12]. However, we later observed another dog developing adenoma secondary to ICRP that had been included as a dog with ICRPs that were well controlled with immunosuppressive therapy.…”

“…In summary, we described how adenomatous colorectal polyps developed secondary to ICRPs in 2 miniature dachshunds over a long period of time. In a previous retrospective study, we briefly reported that 1 of 30 miniature dachshunds with ICRP developed adenoma [12]. However, since a sufficient amount of time for adenoma development had elapsed after initial diagnosis in both cases, the possibility that other miniature dachshunds with well-controlled ICRPs would develop tumors in the future cannot be excluded.…”

“…In humans, ICRPs and polypoid lesions occur in association with inflammatory bowel disease (IBD) and other inflammatory diseases, such as ischemic and infective colitis [2,9,13]. We recently reported that the miniature dachshund is the breed most commonly affected by colorectal polyps, especially ICRPs [12]. ICRPs in miniature dachshunds are characterized by multiple diffuse polyps localized in the colon or rectum.…”

“…ICRPs in miniature dachshunds are characterized by multiple diffuse polyps localized in the colon or rectum. Immunosuppressive therapy with prednisolone and cyclosporine is suggested to be an effective treatment for ICRPs [12]. However, in some cases, immunosuppressive treatment results in a poor therapeutic response, ultimately requiring surgical removal.…”

A Case of Canine Multiple Inflammatory Colorectal Polyps Treated by Endoscopic Polypectomy and Argon Plasma Coagulation

“…These polyps may be derived from neoplasms such as adenomatous polyps, or can be non-neoplastic lesions like inflammatory polyps [11,13,14]. We recently reported that inflammatory colorectal polyps are common in the Miniature Dachshund and typically form multiple diffuse polyps localized to the colon or rectum [8]. Immunosuppressive therapy with prednisolone and cyclosporine is suggested to be an effective treatment for the reduction of polyps and also amelioration of their associated clinical signs [8].…”