Background: Recurrent staphylococcal infections are frequent in dogs with atopic dermatitis (AD). Many factors seem to contribute to making bacterial pyoderma refractory to treatment. Short-term systemic antibiotic therapy is effective for the treatment of acute symptoms, and may, along with pulsatile therapy, contribute to the long-term control of the disease. However, microbial resistance has become a growing and alarming problem. The aim of this study was to evaluate whether the use of Staphylococcus aureus Phage Lysate Staphage Lysate (SPL)®, can minimize the symptoms of recurrent pyoderma and increase the interval between acute atopic manifestations in dogs.Materials, Methods & Results: Thirteen dogs with a history of Canine Atopic Dematitis (CAD) and recurrent bacterial pyoderma received SPL at increasing intervals for 23 weeks. The contents of an intact pustule of each dog was collected and submitted to microbiological analysis. Systemic antibiotic therapy was established for the first 4-6 weeks of SPL protocol, based on the antibiotic sensitivity tests. The animals included in the study underwent a therapeutic protocol receiving shots of 0.5 mL of SPL subcutaneously (SC) twice a week for the first 12 weeks; 1.0 mL of SPL (SC) once a week for four weeks; 1.0 mL of SPL (SC) once every 15 days; 1.0 mL of SPL (SC) after a three-week interval from the last dose on week 20, until final observation at week 26, with no application. The animals underwent clinical examination every week and the evaluation of pruritus was used according Rybnicek et al. During the therapeutic protocol with SPL, a significant decline in the pruritus was observed in the treated dogs (P < 0.05). In week 1, the mean pruritus index was 7.33 on the Rybnicek scale; in weeks 12 and 23, the mean indices were 2.41 and 1.91. An effectiveness of 83.33% for the control of pruritus along with regression of the lesions was observed.Discussion: Before treatment, the selected animals presented worsening of the pruritus during the pyoderma eczema episodes (pruritic), resulting in the emergence of a vicious cycle where the pruritus induced the appearance of new lesions, requiring the use of antibiotics for a long period. During the therapeutic protocol with SPL, a significant decline in the pruritus was observed in the treated dogs. The control of pruritus associated with pyoderma eczema of the dogs in this study before the vaccination protocol with SPL was satisfactory when they were subjected to antibiotic therapy; however, after suspending therapy, the bacterial infections recurred, on average, after 2-4 weeks. On the other hand, with the use of SPL, the animals were recurrence-free until the end of the experimental protocol. This was attributed to the antibiotic therapy administered at the beginning of the protocol, as this led to a regression of the bacterial pyoderma and involution of the lesions. However, after suspending antibiotics, it was observed that, by the end of the study, 83.33% of the dogs still had a low level of pruritus, few or no lesions, which were considered acceptable to most owners. At this moment none of these patients needed to be subjected to antibiotic treatment. The sums of the scores for the dogs on weeks 1, 12, and 23 were 53.33, 4.41, and 3.5, respectively, indicating significant improvements of the lesions, showing that the proposed protocol with SPL was able to prevent new episodes of pyoderma.
Use of Staphylococcus aureus Phage Lysate Staphage Lysate (SPL)® for the Control of Recurrent Pyoderma Eczema in Dogs with Atopic Dermatitis
