Traversa et al. Parasites Vectors (2019) 12:97 https://doi.org/10.1186/s13071-019-3361-7 Parasites & Vectors RESEARCH Open Access Pilot study evaluating the efcacy of a topical formulation containing emodepside and praziquantel in the treatment of natural feline troglostrongylosis Donato Traversa1, Fabrizia Veronesi2, Patrizia Danesi3, Simone Morelli1, Paolo E. Crisi1, Giulia Morganti2, Rafaella Iorio1, Fabrizio Pampurini4, Roland Schaper5, Azzurra Santoro2, Barbara Paoletti1 and Angela Di Cesare1* Abstract Background: Troglostrongylus brevior, a lungworm usually afecting wild felids, has been recently recorded in a number of cases in domestic cats, mainly in Mediterranean areas. Although feline troglostrongylosis is a severe and life-threatening disease, especially in young cats, treatment options are very limited. The present study evaluated the efcacy and safety of a spot-on formulation containing emodepside 2.1% and praziquantel 8.6% (Profender ®, Bayer), which is licensed for treatment of the more common cat lungworm Aelurostrongylus abstrusus, for the treatment of natural troglostrongylosis. Methods: Sixteen cats enrolled in the study were 1:1 allocated to two groups, i.e. Group T, treated with Profender ® spot-on on days 0 and 14 ( 2) at the recommended clinical dose, and Group C which remained untreated. After ± study completion, the control cats received two rescue treatments with Profender® on days 28 ( 2) and 42 ( 2). The primary efcacy criterion was the absence of T. brevior L1 following treatment. Other efcacy parameters± were± the quantitative comparison of L1 presence before (baseline) and after treatment in both groups, and the comparison of clinical signs pre- and post-treatment. Results: In terms of stopping larval shedding, Profender® showed an efcacy of 97% and 97.5% (arithmetic and geometric means, respectively) for group T, 97.1% and 98.5% for group C after one administration, and 100% for both groups after two doses. Overall, 12 cats showed clinical signs related to T. brevior. Specifcally, 9 were clinically afected before treatment while clinical signs appeared after the frst treatment in 3 cats. At the end of the study, all symp- tomatic cats fully recovered with the exception of 3 cats that showed clinical signs similar to those observed at the pre-treatment examination at the end of the study. Conclusions: This study shows that Profender® is efective against T. brevior. Keywords: Troglostrongylus brevior, Cat, Emodepside, Treatment *Correspondence: [email protected] 1 Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy Full list of author information is available at the end of the article © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creat iveco mmons .org/licen ses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creat iveco mmons .org/ publi cdoma in/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Traversa et al. Parasites Vectors (2019) 12:97 Page 2 of 6 Background of feline troglostrongylosis in a case series of naturally Feline troglostrongylosis is an emerging gastropod- infected animals. borne disease caused by the metastrongyloid lungworm Troglostrongylus brevior [1]. Tis parasite usually afects Methods wild felids but recently several cases of infection in Te study was a blinded, randomized, negative-con- domestic cats have been described [2]. Adult stages live trolled feld trial carried out at three sites located in in bronchi and bronchioles and, after mating, females endemic areas of the Umbria (Site A) and Abruzzo (Sites produce eggs that hatch releasing frst-stage larvae (L1), B and C) regions of central Italy. which migrate to the pharynx, where they are swallowed and then shed in feces [1, 3–5]. Te life-cycle of T. brev- Pre‑inclusion screening ior is similar to that of the globally distributed and well- Privately owned cats were enrolled upon informed con- known cat lungworm Aelurostrongylus abstrusus and sent signed by the owner. Individual fecal samples from cats become infected by ingesting third-stage larvae (L3) 165 cats, i.e. 85, 54 and 26 from sites A, B and C, respec- in intermediate hosts, i.e. slugs and snails, or paratenic tively, were collected and tested using the Baermann hosts, i.e. rodents, amphibians, birds and reptiles [3, 4]. migration method for the presence of T. brevior L1 on Additionally, a vertical route of transmission has been days -30/-7. Larvae were identifed as T. brevior (Fig. 1) described [6–9]. Although it is not defnitively proven according to morphometric and morphological features how T. brevior is vertically transmitted, it is likely that the [4, 5] and their identity was genetically confrmed using infection takes place in the frst days after birth, likely via species-specifc PCR [7]. A total of 16 (9.7%) positive the colostrum or milk [8]. cats, 9 (10.6%), 5 (9.3%) and 2 (7.7%) from sites A, B and Tus far, feline troglostrongylosis has been mainly C, respectively, were included in the study according to recorded in geographical areas where the natural host, inclusion/exclusion criteria. i.e. the European wildcat, is present, e.g. Italy, Spain, Greece, Bulgaria [2, 9, 10]. Te clinical picture in cats Inclusion and exclusion criteria infected with T. brevior is characterized by respiratory Cats were enrolled in the study according to the inclu- distress (i.e. cough, dyspnea, polypnea, nasal discharge, sion/exclusion criteria as follows. Inclusion criteria: (i) irreversible pulmonary hypertension), and non-respira- cats in good general health for which the owner signed tory signs (i.e. anorexia, dehydration, poor general con- the owner consent form; (ii) copromicroscopic detection dition, depression) [4, 9, 11, 12]. Te severity of clinical of L1 of T. brevior in at least one Baermann examina- signs is greater in younger cats and, especially in animals tion performed between days -30 and -7, whose identity only a few weeks- or months-old, the infection is life- has been confrmed by PCR. Exclusion criteria: (i) cats threatening [2, 4, 7, 8, 13]. treated with a macrocyclic lactone or other anthelmintics Despite the major pathogenic role of T. brevior, very with a systemic biodistribution within 2 months before few therapeutic options are available. Tus far, the only the study; (ii) cats afected by concomitant parasitic res- licensed product is a spot-on formulation containing piratory infections; (iii) cats less than 8 weeks-old; (iv) eprinomectin 0.4% in combination with fpronil 8.3%, cats weighing less than 0.5 kg; (v) pregnant or lactating (S)-methoprene 10% and praziquantel 8.3% (Broadline®, Merial-Boehringer Ingelheim). In feld conditions this product has shown an efcacy of up to 100% [10, 14], but it should be taken into account that, when specifed by the SPC (summary of product characteristics) it is exclu- sively indicated when cestodes, nematodes and ectopara- sites are to be targeted at the same time. Te spot-on formulation containing emodepside 2.1% and praziquantel 8.6% (Profender®, Bayer) is efcacious for treating natural [15] and experimental [16] infec- tions caused by the cat lungworm A. abstrusus, and it has recently been labelled for this purpose in the Euro- pean Union. Furthermore, its efcacy against T. brevior showed to be promising in individual clinical cases, even in mixed infections caused by other respiratory nema- todes [8, 12, 13]. Te present pilot study has evaluated for the frst time the efcacy of Profender® in the treatment Fig. 1 First-stage larva of Troglostrongylus brevior Traversa et al. Parasites Vectors (2019) 12:97 Page 3 of 6 cats; (vi) animals with severe clinical signs of troglostron- where Mean LPG was calculated as arithmetic and gylosis or sufering from other health conditions. geometric means. All 16 cats fulflled the inclusion criteria and on days (ii) Comparison of qualitative and quantitative pres- -7/0 were clinically and copromicroscopically examined ence of L1 before (baseline) and after the rescue with a quantitative Baermann test to assess values of T. treatment in Group C, according to the above for- brevior larvae per gram of feces (LPG). mula. (iii) Post-treatment clinical evaluation of clinically Treatment and post‑treatment evaluation afected cats within Groups T and C, compared On day 0 each cat underwent a clinical examination, was with pre-treatment clinical evaluations. weighed and randomly assigned to the treatment (T) or to the control (C) Group. Cats of Group T (n = 8 cats) were treated with Profender ® spot-on on days 0 and 14 Results ® (± 2) at the recommended clinical dose, while cats of All cats included in the efcacy evaluation of Profender Group C remained untreated and, after study comple- completed the study according to protocol and none of tion, received two rescue treatments on days 28 (± 2) and them showed any adverse event. 42 (± 2). Larval counts were again performed post-treatment on Efcacy Qualitative efcacy days 14 (± 2) and 28 (± 2) for Group T and on days 42 (± 2) and 56 (± 2) for Group C. On day 0 and the same Overall, 7 out of 8 cats from both Groups T and C day of each copromicroscopic test all cats underwent a (87.5%) were negative in the Baermann examination on physical examination to evaluate the presence of clinical days 14 (± 2) and 42 (± 2) after a single administration of signs associated with troglostrongylosis. Te cats were Profender®, respectively. also observed daily by their owners for the entire period Te second administration of the drugs guaranteed of the study. cessation of larval excretion in the remaining two cats (100%), i.e.