Efficacy of oral fluralaner for the treatment of canine generalized demodicosis: a molecular-level confirmation

Abstract

Background Canine generalized demodicosis is a common parasitic disease caused by the proliferation of Demodex mites. The introduction of isoxazoline class treatments in veterinary dermatology has resulted in apparently effective treatment of generalized demodicosis. The objective of this study was to evaluate the effectiveness of fluralaner for the treatment of canine generalized demodicosis using real-time PCR for the detection and quantification of Demodex DNA. Methods Twenty privately owned dogs with clinical symptoms of generalized demodicosis and deep skin scrapings positive for Demodex canis mites were enrolled in the study. Following diagnosis (day 0) each dog was treated with fluralaner at the recommended commercial dose for tick and flea treatment (25–56 mg/kg) based on body weight. Clinical and mite count assessments, and hair sampling for molecular analyses were performed on days 0, 28, 56, 84 and 112. Demodex DNA was detected and quantified using real-time PCR. Results A single oral dose of fluralaner reduced Demodex mite counts in skin scrapings by an average of 98.9% in all dogs by day 28. No mites were recovered from skin scrapings from any treated dog by day 56, at which time the dog was considered to be clinically cured, with total hair regrowth. There were significant differences among examined dogs in qPCR cycle threshold (Ct) values on days 0, 28, 56, 84 and 112. Demodex DNA levels decreased (increasing Ct values) throughout the study. Mite DNA was present on day 112, possibly from dead mites, at values significantly lower than in samples taken on days 0, 28 and 56. Based on qPCR testing of diluted samples, the Demodex mite population was reduced by approximately 1000-fold on day 112. Conclusions Oral administration of fluralaner at the recommended dose to dogs with generalized demodicosis is highly effective for reducing Demodex mite populations and resolving clinical signs of generalized demodicosis. The presence of mite DNA may indicate that treatment did not kill all Demodex mites.

A European Field Assessment of the efficacy of fluralaner (Bravecto®) chewable and spot-on formulations for treatment of dogs with generalized demodicosis

“…Three consecutive treatments at 4-weekly or monthly intervals were used in separate studies of sarolaner [11] and afoxolaner [12], and in an uncontrolled study with lotilaner [13]. Two studies, one of which was uncontrolled, investigated single-treatment uralaner e cacy using the chewable formulation [10,23], and one controlled study involved the spot-on formulation [17]. The multiple treatments with afoxolaner, sarolaner, and lotilaner, and the single treatment controlled study with either uralaner formulation, all reduced mean demodectic mite counts by >99% within the month following the day 0 treatment, and by 100% at days 81 or 84.…”

“…Across those studies, the reported e cacies of imidacloprid-moxidectin within the month after the rst treatment ranged from 9.8 to 89.8%, and on day 84, following multiple treatments, from 0 to 100%. In the uncontrolled oral uralaner study, PCR analysis of hair collected from treated dogs found that Demodex DNA levels progressively declined throughout the study, and on day 112 were reduced 1000-fold from pre-treatment levels [23]. Thus, the accumulating data in which the isoxazolines have shown potent e cacy and superiority over imidacloprid-moxidectin indicate that they would be the treatment of choice for generalized demodicosis, although further controlled studies would be helpful to con rm that the miticidal e cacy of afoxolaner and lotilaner is maintained under eld conditions.…”

A European field assessment of the efficacy of fluralaner (Bravecto®) chewable and spot-on formulations for treatment of dogs with generalized demodicosis

“…Three consecutive treatments at 4-weekly or monthly intervals were used in separate studies of sarolaner [11] and afoxolaner [12], and in an uncontrolled study with lotilaner [13]. Two studies, one of which was uncontrolled, investigated single-treatment fluralaner efficacy using the chewable formulation [10,23], and one controlled study involved the spot-on formulation [17]. The multiple treatments with afoxolaner, sarolaner and lotilaner, and the single treatment controlled study with either fluralaner formulation, all reduced mean demodectic mite counts by > 99% within the month following the Day 0 treatment, and by 100% at Days 81 or 84.…”

A European Field Assessment of the efficacy of fluralaner (Bravecto®) chewable and spot-on formulations for treatment of dogs with generalized demodicosis

“…Three consecutive treatments at 4-weekly or monthly intervals were used in separate studies of sarolaner [11] and afoxolaner [12], and in an uncontrolled study with lotilaner [13]. Two studies, one uncontrolled, investigated single-treatment fluralaner efficacy using the chewable formulation [10,23], and one controlled study involved the spot-on formulation [17]. The multiple treatments with afoxolaner, sarolaner, and lotilaner, and the single treatment controlled study with either fluralaner formulation, all reduced mean demodectic mite counts by >99% within the month following the day 0 treatment, and by 100% at days 81 or 84.…”

“…Across those studies, the reported efficacies of imidacloprid-moxidectin within the month after the first treatment ranged from 9.8 to 89.8%, and on day 84, following multiple treatments, from 0 to 100%. In the uncontrolled oral fluralaner study, PCR analysis of hair collected from treated dogs found that Demodex DNA levels progressively declined throughout the study, and on day 112 were reduced 1000-fold from pre-treatment levels [23]. Thus, the accumulating data in which the isoxazolines have shown potent efficacy and superiority over imidacloprid-moxidectin indicate that they would be the treatment of choice for generalized demodicosis, although further controlled studies would be helpful to confirm that the miticidal efficacy of afoxolaner and lotilaner is maintained under field conditions.…”