Effectiveness of sarolaner in the clinical management of furuncular myiasis in dogs naturally infested with Dermatobia hominis (Diptera: Cuterebridae)

Paula A Andriotti,Julio I Fernandes,Priscila C Oliveira,Guilherme G Verocai,Clarissa P Souza,Rodrigo C Melo

doi:10.1186/s13071-021-04910-3

Abstract

BackgroundThe human botfly, Dermatobia hominis, is a common cause of furuncular myiasis in dogs in Latin America. Lesions can be single or multiple, each harboring an individual larva, presented as an erythematous nodule that causes pruritus and pain. Typical treatment consists of sedation for removal of larvae by surgical incision or manual pressure. Medications to kill the larva before its extraction can reduce inflammation and discomfort and provide a less traumatic larval removal. Isoxazolines are broad-spectrum ectoparasiticides with larvicidal activity previously reported in the treatment of screwworm myiasis in companion animals. The aim of this study was to evaluate the effectiveness of sarolaner as part of the clinical management of furuncular myiasis in dogs caused by D. hominis larvae.MethodsTen short-haired mixed breed dogs naturally infested with D. hominis were enrolled. Clinical diagnosis was achieved by observation of skin nodules and visualization of larval motility through the lesion orifice. Sarolaner was administered at manufacturer recommended dose for fleas and ticks. Lesions were reexamined 24 h post-treatment and assessed for viability of larvae. Larvae were removed by digital compression and identified as D. hominis.ResultsSeventy-five D. hominis larvae were retrieved from ten dogs. No live larvae were observed, demonstrating 100% larvicidal efficacy of sarolaner. Skin lesions were healed 30 days post-treatment and new lesions were not observed.ConclusionsSarolaner seems to be effective as larvicidal treatment for dogs with furuncular myiasis, reducing discomfort caused by the presence of the larva in the skin and facilitating its safe removal.Graphical abstract

Highlights

The human botfly, Dermatobia hominis, is a common cause of furuncular myiasis in dogs in Latin America
The usual treatment for furuncular myiasis consists of complete removal of larva by a surgical incision and insertion of an instrument to pull the larva out or manual pressure preceded by lidocaine injection around the lesions
The use of medications to kill the larvae before their extraction can be an alternative to help reducing inflammation, to prevent discomfort and to allow for a less traumatic larval removal in infested dogs, especially when multiple lesions exist [3]

Summary

Introduction

The human botfly, Dermatobia hominis, is a common cause of furuncular myiasis in dogs in Latin America. Effective off-label use of several isoxazolines has been reported for the treatment of mange mites in different animal species and primary myiasis caused by the New World screw worm fly, Cochliomyia hominivorax, and the Old World screw worm, Chrysomya bezziana, in dogs and cats [4,5,6,7]. The objective of the present study was to evaluate the effectiveness of sarolaner as part of the clinical management of furuncular myiasis in dogs naturally infested with D. hominis larvae.

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Results

Conclusion