Inflammatory Bowel Disease in Dogs: Prognostic Factors for Therapeutic Response

In dogs with idiopathic inflammatory bowel disease (IBD) the response to treatment influences the dog's quality of life, time of survival, economic impact on owners and, sometimes, the decision for euthanasia. The aim of this retrospective single-center study was to evaluate prognostic factors able to influence the response to treatment in dogs with IBD. Dogs with a diagnosis of idiopathic IBD, treated with immunosuppressive drugs, were enrolled. History about drugs and diet previously employed, clinical signs, laboratory findings, treatment, and follow-up, were recorded. Data from September 2004 to December 2014 were reviewed. Group 1, were defined as dogs that had responded to treatment, in which immunosuppressive drugs and antibiotic treatment was discontinued without relapses. Group 2, were defined as dogs that responded to treatment with immunosuppressive drugs but the disease relapsed after interruption of treatment. Group 3, were defined as dogs that did not respond to diet, antibiotic and immunosuppressive drugs. Kaplan-Meier survival curves were obtained for Groups 1, 2 and 3; the survival curves for these groups were compared using the log-rank test. A two stage-analysis was also applied. In the first univariate stage, the variables were screened using x test. In the second stage, factors that screened through p < 0.15 were evaluated using multivariate logistic regression, The odds ratio (OR) and 95% confidence intervals (95% CI) were calculated from the final model. One hundred and four dogs met the inclusion criteria. Dogs of Group 1 and 2 had a median survival longer than dogs of Group 3, 1250 days (range 210–4380) and 913 days (range 61–3100) versus 210 days (range 30–2005), respectively. At univariate regression analysis, a statistical difference in dogs of Group 3 with respect to dogs of Group 1 and 2 in following variables, were observed: previous treatment with steroids; weight loss; prevalence of small bowel diarrhoea; decreased haematocrit, serum albumin, total protein, creatinine, cholesterol; increased concentration of aspartate amino transferase (AST) and alanine aminotransferase (ALT); and received treatment with other immunosuppressive drugs than steroids at diagnosis. In multivariable model analysis previous treatment with steroids (OR = 5.47; 95%CI 1.86–16.11; p = 0.001) and decreased total proteins (OR = 12.5; 95%CI 3.62–41.75; p = 0.016) were independent variables associated with belonging to Group 3. In conclusion response to treatment in dogs with IBD is correlated with time of survival; and previous treatment with steroids along with decrease total proteins are negative prognostic factors because are associated with a lack of response to treatment.