This report describes the different responses to dapsone treatment in two cases of sterile nodular panniculitis (SNP). Two dogs were presented with ulcerative skin lesions, painful and erythematous papules, and nodules. History and physical examination revealed systemic signs such as pyrexia, lethargy, depression, and anorexia, in addition to ulcerated and ruptured nodules on the skin. The dermatological diagnostics included clear taping, trichogram, skin scraping, impression smears, fungal and bacterial cultures, and histopathology and special stainings of multiple punch biopsies obtained from the skin lesions. Based on the clinical and histopathologic findings, the absence of microbiological infection, and the positive response to immunosuppressive therapy, both the dogs were diagnosed with SNP. Although both dogs had been treated with various immunosuppressive drugs including prednisolone, cyclosporine, azathioprine, and triamcinolone, therapy was switched to dapsone due to recurrent dermatological signs and presumed steroidinduced hepatotoxicity. The clinical responses to dapsone were opposite in the two cases. In the first case, combination therapy with prednisolone and cyclosporine was effective in attenuating ulcerative lesions, while dapsone alone did not control the clinical signs. In contrast, in the second case, the therapeutic response to the common immunomodulatory drugs such as prednisolone, triamcinolone, and azathioprine was inadequate. Interestingly, dapsone alone was effective in controlling the clinical signs without causing undue side effects. Although the usefulness of dapsone for the treatment of canine SNP is unknown, it may be considered in mild to moderate cases of SNP when the use of steroids is not recommended due to its low efficacy or side effects.

Introduction
 Case Report
 Discussion
 References

• Sun-Hwa Kim(Veterinary Teaching Hospital, College of Veterinary Medicine, Chungbuk National University)
• Sun-Hyung Cho(Veterinary Teaching Hospital, College of Veterinary Medicine, Chungbuk National University)
• Ji-Houn Kang(Veterinary Teaching Hospital, College of Veterinary Medicine, Chungbuk National University)
• Mhan-Pyo Yang(Veterinary Teaching Hospital, College of Veterinary Medicine, Chungbuk National University)
• In-Pil Mo(Veterinary Teaching Hospital, College of Veterinary Medicine, Chungbuk National University)
• Byeong-Teck Kang(Veterinary Teaching Hospital, College of Veterinary Medicine, Chungbuk National University) Corresponding author