Background – Allergen immunotherapy is a well-established treatment for canine atopic dermatitis (CAD), but non-invasive, safe, effective, and easy-to-use home-administration routes that promote owner’s compliance are needed. Epicutaneous immunotherapy (EPIT) has been suggested as a promising alternative treatment for human allergies. This study primarily evaluated EPIT’s feasibility, effectiveness, and safety for CAD. Methods – Sixteen client-owned dogs with spontaneous, nonseasonal, mite-sensitive CAD were enrolled for a 6-month, once-weekly, 12-hour EPIT. A costume-made 3D-printed device was designed to deliver the allergen-based formulation. Primary efficacy outcomes included the owner’s assessed pruritus (PVAS10) and treatment efficacy (OGATE), and veterinarian-assessed skin lesions (2D-IGA). Secondary efficacy outcomes were the quality-of-life (QoL) and serological allergen-specific IgE’s concentrations. Effectiveness was defined by the success of the primary efficacy outcomes, according to the ICADA’s COSCAD’18 recommendations. EPIT was deemed safe in the absence of severe side-effects. Results – EPIT effectively improved clinical condition, with a success rate of 73.3% for pruritus, 66.7% for skin lesions, and 93.3% for QoL. A good-to-excellent response to EPIT was rated by 93.3% of owners in OGATE. EPIT significantly improved PVAS10 (p=0.000015), 2D-IGA (p=0.006) and QoL (p=0.000014) scores over six months. A significant difference was evident within one month for PVAS10 (p=0.003) and 2D-IGA (p=0.009) scores. Seven dogs partially desensitised to at least one mite and two fully desensitised to all mites after six months. Severe adverse events were not recorded. Conclusions – This pioneer study emphasises EPIT’s potential as a novel and promising, non-invasive, feasible, effective, safe, and well-tolerated CAD treatment, supporting further investigation.