Zonulin, diamine oxidase activities, intestinal ultrasonography and clinical scoring in canine atopic dermatitis

Objective: This study aimed to evaluate the systemic effects of the disease within the context of the gut-brain-skin axis in dogs diagnosed with atopic dermatitis, by measuring serum levels of zonulin and diamine oxidase (DAO), intestinal wall thickness (duodenum, jejunum, colon) via abdominal ultrasonography, and epidermal barrier parameters (skin pH and hydration), as well as by applying the CADESI-04 clinical scoring system. Material and Methods: The animal material of the study consisted of 20 dogs diagnosed with canine atopic dermatitis based on the Favrot (2010) criteria and 20 healthy dogs without any dermatological lesions, presented to the Small Animal Internal Medicine Clinics of the Veterinary Faculty at Aydın Adnan Menderes University. All dogs were evaluated in terms of serum zonulin and DAO levels, intestinal wall thickness, and epidermal barrier parameters. Statistical analysis was performed using the Shapiro-Wilk test, Mann-Whitney U test, and Chi-square test. Results: Dogs with canine atopic dermatitis and healthy control dogs were compared. Zonulin (p = 0.001) and DAO (p = 0.001) levels were significantly higher in the canine atopic dermatitis group. Among epidermal barrier parameters, pH (p = 0.001) and hydration (p = 0.001) levels showed significant differences. According to ultrasonographic findings, only the colon wall thickness differed significantly between groups (p = 0.001). The CADESI-04 clinical score was found to be 88.65 ± 5.63, indicating a high degree of lesion severity. Conculsion: According to the data obtained from the conducted research, the intestinal mucosal damage accompanying increased intestinal permeability in atopic dogs within the 'brain-gut-skin axis' indicates that the term gastroentero-dermatology would be more appropriate than dermatology alone. In this respect, including canine atopic dermatitis, it can be suggested that zonulin and DAO may be useful as biomarkers in various gastroentero-dermatological disorders within the brain-gut-skin axis. Furthermore, treatment strategies targeting increased intestinal permeability should be planned accordingly, and clinical findings and changes in disease activity should be monitored using relevant biomarkers. Key words: Atopy, Diamine-oxidase, Intestine, Ultrasonography, Zonulin.