We treated canine atopic dermatitis that had failed to respond to existing treatments with allogeneic adipose-derived mesenchymal stem cells (Ad-MSCs) for the first time in Japan in anticipation of their immunomodulating and anti-inflammatory effects. Improvement of symptoms was observed within approximately one month, and the dosage of prednisolone and cyclosporine was reduced to less than half of the initial dosage during the observation period of approximately eight months, with no worsening of symptoms. No adverse events were observed during the observation period. The results suggest that Ad-MSCs may be a safe and effective treatment option for refractory canine atopic dermatitis.

A 9-month-old intact female Bengal cat presented with a dry and scaly lesion limited to the nasal planum. After prednisolone administration, partial improvement of the nasal lesion was observed. However, the improvement was only temporary and lesion deterioration was observed again as the treatment continued. A skin scrape test showed only crusts. Wood’s light test and cultivation test showed no sign of fungal infection. Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) were negative, and polymerase chain reaction (PCR) of the nasal swab ruled out bacterial and viral infection. A punch biopsy was performed on the nasal planum 3 weeks after prednisolone cessation. Histopathology revealed laminated orthokeratotic hyperkeratosis and very mild lymphocyte infiltration in the dermis layer. Topical application of difluprednate lotion led to gradual decrease of the lesion and a weekly application of this lotion is maintaining the status.