[Canine sterile neutrophilic dermatosis (Sweet-like syndrome): A description of 3 cases].

Three dogs were presented with a sudden onset of erythematous skin lesions, fever, and various extracutaneous signs, assigned to canine sterile neutrophilic dermatosis by clinical, laboratory, and histopathologic examination. This disease is very rare and comparable to Sweet syndrome in humans. According to the 4 forms of SS, the 1st and 3rd cases in this case report could be classified as classic/idiopathic SS. In this context, the respiratory signs may be a prodromal stage of SS preceding the skin lesions or possibly an infection of the respiratory tract was the trigger for SS. The 2nd case, on the other hand, shows a clear and the 3rd case a possible connection to pathergy as a consequence of a previous surgical treatment (case 2 a tibial plateau levelling osteotomy [TPLO] 20 days previously, case 3 a hemilaminectomy 90 days previously). This way, both may be assigned to the 4th form of SS. In all 3 cases, an adverse drug reaction as a trigger cannot be ruled out with certainty, as medication was used before the diagnosis was made in each case. Besides the most common extracutaneous signs such as fever and neutrophilia, immune-hemolytic anemia occurred in 2 of the patients. As therapeutic options, in addition to the established immunosuppressive drugs such as prednisolone, ciclosporin and azathioprine, oclacitinib is also included in the treatment regimen. In addition, administration of an antiplatelet agent (clopidogrel), which may be interpreted as a lesson learnt from the first of the presented cases, that died of pulmonary thromboembolism. In case 2, all drugs were tapered and eventually stopped over a period of 2.5 years and the patient has been without recurrence for 4 years. Case 3 is recurrence-free under therapy.