Controlled field study evaluating the clinical efficacy of the spot-on formulation containing emodepside 2.1% w/v/ praziquantel 8.6% (Profender®, Bayer Animal Health) in the treatment of natural cat aelurostrongylosis

Aelurostrongylus abstrusus is the most important nematode affecting the respiratory tract of cats in terms of spread and clinical relevance [1]. Few products are labelled to treat aelurostrongylosis and knowledge on clinical response to treatments in relation to the course and the length of clinical recovery needs to be implemented. With the aim to evaluate the efficacy of emodepside/praziquantel (Profender®, Bayer Animal Health) in the treatment of aelurostrongylosis in randomized controlled field conditions, 8 cats received two doses of Profender two weeks apart (T group), while 9 cats (C group) remained untreated and received a rescue treatment at the study day 28. Each owner signed a consent form and accepted to participate in the study. All cats were evaluated every two weeks (physical examination, CBC, serum chemistry, thorax radiographs and Baermann test). A comparison between the two study groups in terms of presence/ absence of clinical signs, clinic-pathological abnormalities and radiographic patterns was done. Cats of the T group were followed-up every two weeks for 10 weeks and clinical response was assessed through a pre- and post-therapy evaluation of clinical and radiographic scores, as previously described [2]. Data were compared using RM one-way- ANOVA or a Friedman test, while Fisher's exact test was used to compare categorical variables. In the T group, a post-treatment reduction of clinical (p <0.01) and radiographic scores (p<0.05) were observed 14 days after the second administration of Profender. However, in comparison to C group, already two weeks after the first application, abnormal lung sounds were recorded less frequently (p<0.05) and hyporexia, lethargy, oculo-nasal discharge and pallor of the mucosae disappeared. Two weeks after the second treatment clinical and parasitological recovery, the resolution of inflammatory leucogram pattern and a significant reduction of radiographic lesions (p<0.01) were observed. The complete regression of radiographic patterns was recorded after 8 weeks from the second application. In this study a partial improvement, was observed two weeks after the first treatment however only the second Profender application ensured the disappearance of clinical and radiographic signs and the parasitological negativization. Therefore, an apparent improvement of clinical picture should not encourage a single application regimen for treating cat aelurostrongylosis with this parasiticide. The safety and efficacy of Profender in treating aelurostrongylosis is here confirmed in controlled field conditions. Two applications of spot-on solution two weeks apart lead to a parasitological negativization and, importantly, to a general improvement of clinical picture, via the early reduction of clinical and radiographic signs, followed by a complete remission of clinic-pathological abnormalities