Efficacy of oral fluralaner (Bravecto) against Tunga penetrans in dogs: A negative control, randomized field study in an endemic community in Brazil

Abstract

The sand flea Tunga penetrans is one of the zoonotic agents of tungiasis, a parasitic skin disease of humans and animals. The dog is one of its main reservoirs. This negatively controlled, randomized, double-masked clinical trial evaluated the therapeutic and residual efficacy of fluralaner for treatment of dogs naturally infested with T. penetrans. Sixty-two dogs from an endemically affected community in Brazil were randomly assigned to either receive oral fluralaner (Bravecto chewable tablets) at a dose of 25 to 56 mg fluralaner/kg body weight, or no treatment (31 dogs per group). Dogs were clinically examined using a severity score for acute canine tungiasis (SCADT), parasitological examinations as defined by the Fortaleza classification, and pictures of lesions on days 0 (inclusion and treatment), 7 ± 2, 14 ± 2, 21 ± 2, 28 ± 2, 60 ± 7, 90 ± 7, 120 ± 7 and 150 ± 7. The percentage of parasite-free dogs after treatment was >90% between days 14 and 90 post-treatment with 100% efficacy on study days 21, 28 and 60. Sand flea counts on fluralaner treated dogs were significantly lower (p<0.025) than control dogs on all counts from day 7 to 120. The number of live sand fleas on treated dogs was reduced by > 90% on day 7, > 95% on days 14 and 90, and 100% from day 21 to 60, and with a significant difference between groups from day 7 to 120. From day 7 to day 120, mean SCADT scores were significantly reduced in treated dogs with a mean of 0.10 compared to 1.54 on day 120 in untreated dogs. Therefore, a single oral fluralaner administration is effective for treating and achieving long lasting (> 12 weeks) prevention for tungiasis in dogs.

Treatment of Animal Tungiasis: What’s New?

“…Disease control in animals considered reservoirs, such as dogs, can be a viable option to control tungiasis in endemic areas [ 44 ]. However, there are few clinical studies evaluating ectoparasiticides’ effectiveness against T. penetrans to control and treat infections in domestic animals [ 35 , 36 , 37 , 38 , 39 ]. Thus, conducting new tests is vital to develop effective and economically viable options for society.…”

“…Fluralaner is a systemic acaricide and insecticide with prolonged efficacy in animals. The drug has commercial oral formulation in the form of palatable tablets at a dosage equivalent to 25–56 mg/kg of bodyweight for dogs [ 35 ].…”

“…The flea counts on fluralaner-treated dogs were significantly lower ( p < 0.025) than on the control dogs at intervals from day 7 to 120. The authors of this study concluded that a single oral dose of fluralaner was effective for treatment, achieving long-term prevention (greater than 12 weeks) of tungiasis in dogs, without side effects on the animals [ 35 ].…”

“…However, controlled studies proving the effectiveness of drugs to treat and protect animals against T. penetrans are scarce [ 33 ]. Currently, a new perspective has emerged in treating tungiasis in dogs, the use of isoxazolines (e.g., fluralaner), which have demonstrated high efficacy [ 34 , 35 ].…”

Characterization of tungiasis infection and morbidity in Kenya reveals increase in disease burden during COVID-19 school closures.

“…The authors developed systematic methods to quantify the severity of disease with severity scores for acute tungiasis (SSAT) and chronic tungiasis (SSCT). Modified versions of these morbidity scores have also been applied to estimate morbidity in pigs and dogs and to quantify the effects of successful treatment on disease severity [15,16].…”