Efficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs

Abstract Background Canine babesiosis is a tick-borne disease of significant veterinary importance in dogs. It is caused by Babesia canis in Europe, where it is transmitted by Dermacentor reticulatus ticks. Methods A blinded, randomized, good clinical practice (GCP) and negative control experimental...

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Main Authors: Eric Tielemans, Carin Rautenbach, Alta Viljoen, Frederic Beugnet
Format: Article
Language:English
Published: BMC 2025-04-01
Series:Parasites & Vectors
Subjects:
Online Access:https://doi.org/10.1186/s13071-025-06787-y
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author Eric Tielemans
Carin Rautenbach
Alta Viljoen
Frederic Beugnet
author_facet Eric Tielemans
Carin Rautenbach
Alta Viljoen
Frederic Beugnet
author_sort Eric Tielemans
collection DOAJ
description Abstract Background Canine babesiosis is a tick-borne disease of significant veterinary importance in dogs. It is caused by Babesia canis in Europe, where it is transmitted by Dermacentor reticulatus ticks. Methods A blinded, randomized, good clinical practice (GCP) and negative control experimental study was conducted to verify the efficacy of NexGard Spectra® in reducing the transmission of B. canis by D. reticulatus to dogs. NexGard Spectra® (IVP) is an oral product for dogs combining afoxolaner, an acaricide/insecticide compound from the isoxazoline class, and milbemycin oxime, a nematicide compound from the macrocyclic lactone class. Three groups of eight dogs were used; one group orally treated on day 0 with the IVP at the minimum recommended dose and two untreated control groups. On day 1, dogs from the treated group and from control group 1 were infested with 50 D. reticulatus adult ticks of 50/50 sex ratio infected with B. canis at a 23% infection rate. On day 28, dogs from the treated group and from control group 2 were infested similarly to those on day 1. Ticks were removed 6 days after each infestation. Results Seven to nine days after each infestation, all untreated control dogs displayed clinical signs of canine babesiosis, i.e., lethargy, and/or dark urine, and/or > 39.5 °C rectal temperature. Blood was collected for microscopical blood smear examination, and for polymerase chain reaction (PCR) analysis. The blood smears from all untreated control dogs were positive for Babesia and all the PCR analyses were positive for B. canis. The control dogs were rescue treated. All control dogs were confirmed positive for B. canis by IFA on day 21 (control group 1) and on day 42 (control group 2). None of the IVP-treated dogs expressed any clinical sign of canine babesiosis following each of the two infestations of days 1 and 28 and until day 56. Blood was collected for IFA and PCR analyses from the treated dogs on days 21, 28, 42, and 56, and all results were negative. Conclusions In this study, the antiparasitic treatment prevented the transmission of B. canis to dogs following induced infestations. Graphical Abstract
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spelling doaj-art-db39e56b0e034f0f926dba265a97011d2025-08-20T03:18:42ZengBMCParasites & Vectors1756-33052025-04-011811810.1186/s13071-025-06787-yEfficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogsEric Tielemans0Carin Rautenbach1Alta Viljoen2Frederic Beugnet3Boehringer Ingelheim Animal HealthClinvet International (Pty) Ltd.Clinvet International (Pty) Ltd.Boehringer Ingelheim Animal HealthAbstract Background Canine babesiosis is a tick-borne disease of significant veterinary importance in dogs. It is caused by Babesia canis in Europe, where it is transmitted by Dermacentor reticulatus ticks. Methods A blinded, randomized, good clinical practice (GCP) and negative control experimental study was conducted to verify the efficacy of NexGard Spectra® in reducing the transmission of B. canis by D. reticulatus to dogs. NexGard Spectra® (IVP) is an oral product for dogs combining afoxolaner, an acaricide/insecticide compound from the isoxazoline class, and milbemycin oxime, a nematicide compound from the macrocyclic lactone class. Three groups of eight dogs were used; one group orally treated on day 0 with the IVP at the minimum recommended dose and two untreated control groups. On day 1, dogs from the treated group and from control group 1 were infested with 50 D. reticulatus adult ticks of 50/50 sex ratio infected with B. canis at a 23% infection rate. On day 28, dogs from the treated group and from control group 2 were infested similarly to those on day 1. Ticks were removed 6 days after each infestation. Results Seven to nine days after each infestation, all untreated control dogs displayed clinical signs of canine babesiosis, i.e., lethargy, and/or dark urine, and/or > 39.5 °C rectal temperature. Blood was collected for microscopical blood smear examination, and for polymerase chain reaction (PCR) analysis. The blood smears from all untreated control dogs were positive for Babesia and all the PCR analyses were positive for B. canis. The control dogs were rescue treated. All control dogs were confirmed positive for B. canis by IFA on day 21 (control group 1) and on day 42 (control group 2). None of the IVP-treated dogs expressed any clinical sign of canine babesiosis following each of the two infestations of days 1 and 28 and until day 56. Blood was collected for IFA and PCR analyses from the treated dogs on days 21, 28, 42, and 56, and all results were negative. Conclusions In this study, the antiparasitic treatment prevented the transmission of B. canis to dogs following induced infestations. Graphical Abstracthttps://doi.org/10.1186/s13071-025-06787-yAfoxolanerDogBabesia canisDermacentor reticulatusPrevention of transmission
spellingShingle Eric Tielemans
Carin Rautenbach
Alta Viljoen
Frederic Beugnet
Efficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs
Parasites & Vectors
Afoxolaner
Dog
Babesia canis
Dermacentor reticulatus
Prevention of transmission
title Efficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs
title_full Efficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs
title_fullStr Efficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs
title_full_unstemmed Efficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs
title_short Efficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of Babesia canis by Dermacentor reticulatus ticks to dogs
title_sort efficacy of an oral combination of afoxolaner and milbemycin oxime for the prevention of transmission of babesia canis by dermacentor reticulatus ticks to dogs
topic Afoxolaner
Dog
Babesia canis
Dermacentor reticulatus
Prevention of transmission
url https://doi.org/10.1186/s13071-025-06787-y
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