Evaluation of sarolaner and spinosad oral treatments to eliminate fleas, reduce dermatologic lesions and minimize pruritus in naturally infested dogs in west Central Florida, USA

Michael W Dryden,Nicole Smith,Michael S Canfield,Todd S Bress,Kaitlin M Foley,Amber Smith,Vicki Smith,Emily Niedfeldt,Kimberly Kalosy,Mike Endrizzi,Joyce Login,Amanda Kinnon

doi:10.1186/s13071-017-2328-9

Michael W Dryden, Nicole Smith + Show 10 more

Open Access

https://doi.org/10.1186/s13071-017-2328-9

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Abstract

BackgroundAn in-home investigation of naturally flea infested dogs was conducted in West Central Florida, USA to evaluate and compare the effectiveness of two different oral flea adulticides to control flea infestations, minimize dermatologic lesions and reduce pruritus over an 8-week period.MethodsTwenty-nine dogs living in 19 homes and another 26 dogs residing in 16 different homes were orally administered either a sarolaner or spinosad chewable, respectively on day 0 and once between days 28–30. Products were administered by study personnel according to label directions. Flea populations on dogs were estimated using visual area counts and flea infestations in the indoor premises were assessed using intermittent-light flea traps on days 0, 7, 14, 21 and once between days 28–30, 40–45, and 56–60. Assessments of dermatologic lesions were conducted monthly during the study and severity of pruritus was evaluated throughout the study on the same schedule as flea counts were conducted. Concurrent treatments for existing skin disease were not allowed.ResultsThe administration of sarolaner or spinosad reduced flea populations on dogs by 99.0% and 97.3%, respectively within 7 days. Flea infestations on the sarolaner- and spinosad-treated dogs were reduced by > 99% at every counting period from day 14 post-treatment through the end of the 8-week study. At the end of the study 96.4 and 92.0% of the dogs treated with sarolaner and spinosad, respectively were flea-free. Flea populations in the indoor premises were also markedly reduced the end of the study, with 100 and 99.8% reductions in flea trap counts in the sarolaner and spinosad treatment groups, respectively. FAD lesion scores, atopic dermatitis lesions scores (CADESI-4) and pruritus severity scores were also markedly improved with both formulations.ConclusionsAn in-home clinical field study conducted during the summer of 2016 in subtropical Florida demonstrated that two-monthly administrations of either sarolaner or spinosad chewables almost completely eliminated flea infestations on dogs and in private residences, while markedly reducing dermatology lesions and pruritus.

Highlights

An in-home investigation of naturally flea infested dogs was conducted in West Central Florida, USA to evaluate and compare the effectiveness of two different oral flea adulticides to control flea infestations, minimize dermatologic lesions and reduce pruritus over an 8-week period
Data from one home with one qualifying dog was not collected on the last assessment day because the owner would not return phone calls to make an appointment
One dog was lost on the last day of the study because the owner became agitated and uncooperative during the visit

Summary

Introduction

An in-home investigation of naturally flea infested dogs was conducted in West Central Florida, USA to evaluate and compare the effectiveness of two different oral flea adulticides to control flea infestations, minimize dermatologic lesions and reduce pruritus over an 8-week period. The isoxazolines are a new class of ectoparasiticides with potent insecticide and acaracide activity After oral administration, these compounds have a high bioavailability with a rapid elimination of existing flea and tick infestations and protective efficacy for the duration of the dosing interval [7]. Sarolaner is effective in eliminating existing flea infestations on dogs and provides protective control against reinfestation for 35 days [8, 9]. It has been demonstrated that fleas begin to die within 3 to 4 h after sarolaner administration with > 98% elimination of fleas by 8 h and residual efficacy >95.7% within 12 h after reinfestation 35 days post-treatment, which was sufficient to prevent flea egg deposition during the entire 5-week post-treatment period [10]. Studies have shown sarolaner to be efficacious in the treatment of Sarcoptes and Demodex mange mites, as well for the treatment of Otodectes ear mites [11, 12]

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