Efficacy of a topical formulation containing esafoxolaner, eprinomectin and praziquantel (NexGard Combo®) against natural infestations with the cat louse, Felicola subrostratus under field conditions.

Felicola subrostratus is the only species of louse affecting domestic cats. Although it is considered a rare ectoparasite of pet cats, it occurs mainly in stray or shelter animals and is sometimes associated with intense pruritus and secondary bacterial infections. The aim of the present study was to evaluate the efficacy of a single dose of the topical formulation of esafoxolaner, eprinomectin and praziquantel (NexGard Combo®, Boehringer Ingelheim) in cats for the treatment of naturally acquired chewing lice infestation in a multi-site, positive-control, blinded clinical field study. Thirty-one domestic cats presenting natural F. subrostratus infestation were included in the study. The animals had not been treated with any ectoparasiticide within the previous 60 days. After inclusion, each cat was randomly assigned to one of the two groups: group 1, 14 cats treated with NexGard Combo® or group 2, 17 cats treated with Frontline Combo®. A clinical evaluation was performed at days 0 (inclusion), 14 and 30 and consisted in scoring the skin lesions and symptoms and scoring the presence of lice. On day 30, all cats from both groups scored 0 for the presence of live lice and no dead lice were found, demonstrating 100% efficacy. The clinical scores significantly improved from day 0 to day 30 in both groups. During the 30 days of surveillance, no reinfestations due to the hatching of eggs were observed and none of the cats had any adverse reactions. Esafoxolaner demonstrated high efficacy for the treatment of F. subrostratus infestation.

Title: Efficacité d'une formulation topique contenant de l'esafoxolaner, de l'éprinomectine et du praziquantel (NexGard Combo®) contre les infestations naturelles par le pou du chat, Felicola subrostratus, dans des conditions de terrain. Abstract: Felicola subrostratus est la seule espèce de pou affectant les chats domestiques. Bien que ce pou soit rare comme ectoparasite chez les chats de compagnie, il infeste principalement les animaux errants ou en refuge et est parfois associé à un prurit intense et à des infections bactériennes secondaires. Le but de la présente étude était d'évaluer l'efficacité d'une dose unique de la formulation topique d'esafoxolaner, d'éprinomectine et de praziquantel (NexGard Combo®, Boehringer Ingelheim) chez le chat pour le traitement de l'infestation naturelle par les poux broyeurs dans une étude de terrain multi-sites, randomisée, avec un contrôle positif. Trente et un chats domestiques présentant une infestation naturelle par F. subrostratus ont été inclus dans l'étude. Les animaux n'avaient été traités avec aucun ectoparasiticide au cours des 60 jours précédents. Après inclusion, chaque chat a été assigné au hasard à l'un des deux groupes : groupe 1, 14 chats traités avec NexGard Combo®, ou groupe 2, 17 chats traités avec Frontline Combo®. Une évaluation clinique a été réalisée aux jours 0 (inclusion), 14 et 30 et a consisté à un score clinique des lésions et symptômes cutanés et à noter la présence de poux. Au jour 30, tous les chats des deux groupes ont obtenu un score de 0 pour la présence de poux vivants et aucun pou mort n'a été trouvé, démontrant une efficacité de 100 %. Les scores cliniques se sont significativement améliorés du jour 0 au jour 30 dans les deux groupes. Au cours des 30 jours de surveillance, aucune réinfestation due à l'éclosion des œufs n'a été observée et aucun des chats n'a présenté d'effet indésirable. L'esafoxolaner a démontré une efficacité élevée pour le traitement de l'infestation par F. subrostratus.

Efficacy of afoxolaner (NexGard®) against natural infestations with Trichodectes canis in dogs under field conditions.

BACKGROUND: Trichodectes canis is a small chewing louse found globally that primarily infests dogs. Limited information is available on the efficacy of isoxazolines against infestation with the chewing louse. In the present study, we evaluated the efficacy of afoxolaner, an isoxazoline class compound, in naturally infested domestic dogs. METHODS: The field study was carried out in Romania. Between September 2021 and December 2021, 43 dogs with confirmed T. canis infestation were included in the study. On the day of the inclusion (day 0), each animal was clinically examined and randomly treated with a control product labeled for use against lice [fipronil-(S)-methoprene combination (Frontline Combo®; Boehringer Ingelheim)] or with the investigational product [chewable tablets containing afoxolaner (NexGard®; isoxazoline)]. Each animal was evaluated for the presence of lice at 15 and 30 days post-inclusion. RESULTS: Of the 48 dogs initially included in the study, 43 completed the treatment period [18 in the control group (CG) and 25 in the investigational group (IG)]. At day 14, no living T. canis lice were detected on the dogs in either group. At day 14, dead lice were detected in four dogs in the IG, while eggs were present in two dogs in the IG and in one dog in the CG. At day 30, no lice were detected in either group, while eggs were still present in one dog in the CG. CONCLUSION: These results suggest that afoxolaner is a feasible treatment option against chewing lice in dogs, providing 100% curative efficacy.