Conventional and rush immunotherapy in canine atopic dermatitis

Abstract

The purposes of this double‐blinded, randomized study were to determine the success rate of rush immunotherapy in canine atopic dermatitis and compare it to conventional immunotherapy, and to assess if rush immunotherapy leads to a quicker reduction in clinical signs than conventional immunotherapy. Twenty‐two atopic dogs diagnosed by history, physical examination and appropriate exclusion of differential diagnoses were included in the study. Offending allergens were identified with an intradermal test. All dogs were premedicated for 3 days with an antihistamine, and then hospitalized for 1 day. Injections with prepared treatment sets were administered every 30 min subcutaneously for 7 h; dogs were then discharged and continued on immunotherapy for 1 year. All dogs were evaluated monthly by their owners for 12 months, and by clinicians prior to therapy and after 3, 6, 9 and 12 months of therapy using a standardized scoring system to measure pruritus, lesions present and any concurrent medications given. Eleven dogs were treated with rush immunotherapy, and 11 dogs with conventional immunotherapy. Significant differences in mean pruritus, medication, lesion and total scores between groups were determined by use of a repeated‐measures ANOVA. Mean pruritus scores decreased from 13.5 to 6.7 (P = 0.0333) and from 13.9 to 10.3, medication scores from 23.6 to 10.6 (P = 0.0001) and from 14.1 to 13.6, lesion scores from 5.9 to 1.6 (P = 0.0001) and from 3.0 to 1.9, and total scores from 42 to 18.1 (P = 0.001) and from 30.6 to 21.5 in the rush immunotherapy group and in the conventional immunotherapy group, respectively. Using a Tukey–Kramer Multiple Comparison test, differences between the total scores at the beginning of the study and at the various time points reached significance after 3 months. An improvement of >50% in pruritus was noted in six of 11 dogs in the rush immunotherapy group and in five of 11 dogs in the conventional immunotherapy group; similar improvements in lesion scores and total scores were observed in dogs treated with rush immunotherapy (seven of 11 and five of 11 dogs, respectively) and in dogs treated with conventional immunotherapy (seven of 11 and four of 11 dogs, respectively). Based on these results, rush immunotherapy seems to be associated with a higher success rate than conventional immunotherapy, and improvement is typically seen within the first 6 months of therapy. Funding: Morris Animal Foundation.