title: Efficacy of leflunomide for treatment of refractory inflammatory colorectal polyps in 15 Miniature Dachshunds.
abstract: Inflammatory colorectal polyp (ICRP), common in miniature dachshunds, presents with hematochezia, tenesmus and mucoid feces. Although an 80% response rate has been reported when treated with prednisolone and cyclosporine, effective treatment is needed for the remaining 20% of ICRP dogs. Leflunomide is an immunosuppressive drug reported as effective in several immune-mediated diseases. In the present study, we retrospectively evaluated the efficacy and adverse effects of leflunomide in 15 ICRP dogs that were refractory to treatment with prednisolone and cyclosporine. Treatment efficacy was assessed by endoscopy, clinical symptoms and rectal palpation. Adverse effects were determined by clinical symptoms and blood testing during follow-up. The leflunomide treatment response rate was 93.3%. The median dosage of leflunomide and the median response time were 3 mg/kg (range: 1.7-4.0 mg/kg) and 35 days (range: 20-119 days), respectively. Adverse effects observed included lethargy (3 dogs), anorexia (1 dog), respiratory symptoms (1 dog), leukocytopenia (2 dogs), thrombocytopenia (1 dog), anemia (1 dog) and liver enzyme elevation (8 dogs). Most of the adverse effects improved with symptomatic treatment and leflunomide discontinuation or dosage reduction. In conclusion, leflunomide treatment is effective in ICRP dogs refractory to treatment with prednisolone and cyclosporine. Because several adverse effects were observed, close monitoring is needed during leflunomide treatment follow-up.
authors.affiliation: Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Fukushima
authors.forename: Nozomi
authors.initials: N
authors.lastname: Eguchi
authors.forename: Koichi
authors.initials: K
authors.lastname: Ohno
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kanemoto
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Igarashi
authors.forename: Aki
authors.initials: A
authors.lastname: Ohmi
authors.forename: Ko
authors.initials: K
authors.lastname: Nakashima
authors.forename: Hajime
authors.initials: H
authors.lastname: Tsujimoto
mesh_terms: D000818:Animals; D003111:Colonic Polyps / Q000662:veterinary*; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D005260:Female; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D007417:Intestinal Polyps / Q000662:veterinary*; D007555:Isoxazoles / Q000009:adverse effects / Q000627:therapeutic use*; D000077339:Leflunomide; D008297:Male; D012189:Retrospective Studies
chemical_list: D007166:Immunosuppressive Agents; D007555:Isoxazoles; D000077339:Leflunomide