A quantitative evaluation of the extent of fluralaner uptake by ticks (Ixodes ricinus, Ixodes scapularis) in fluralaner (Bravecto TM) treated vs. untreated dogs using the parameters tick weight and coxal index

Particle and Fibre Toxicology

Anja R. Heckeroth¹  Eva Zschiesche¹  Rainer K.A. Roepke¹  Janina Taenzler¹  Janina Demeler²  Heike Williams¹ 

[1] MSD Animal Health Innovation GmbH, Research Antiparasitics, Zur Propstei, Schwabenheim, 55270, Germany;Free University of Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Robert-von-Ostertag-Str. 2, Berlin, 14163, Germany

关键词: Efficacy;    Ixodes scapularis;    Ixodes ricinus;    Coxal index;    Tick weight;    Dog;    Fluralaner;    BravectoTM chewable tablets;   

Others  :  1224185
DOI  :  10.1186/s13071-015-0963-6

 received in 2015-04-13, accepted in 2015-06-23,  发布年份 2015

【 摘 要 】

Background

Fluralaner is a new antiparasitic drug that was recently introduced as Bravecto ^TMchewable tablets for the treatment of tick and flea infestations in dogs. Most marketed tick products exert their effect via topical application and contact exposure to the parasite. In contrast, Bravecto ^TMdelivers its acaricidal activity through systemic exposure. Tick exposure to fluralaner occurs after attachment to orally treated dogs, which induces a tick-killing effect within 12 h. The fast onset of killing lasts over the entire treatment interval (12 weeks) and suggests that only marginal uptake by ticks is required to induce efficacy. Three laboratory studies were conducted to quantify the extent of uptake by comparison of ticks’ weight and coxal index obtained from Bravecto ^TM -treated and negative-control dogs.

Methods

Three studies were conducted using experimental tick infestation with either Ixodes ricinus or Ixodes scapularis after oral administration of fluralaner to dogs. All studies included a treated (Bravecto ^TMchewable tablets, MSD Animal Health) and a negative control group. Each study had a similar design for assessing vitality and weighing of ticks collected from dogs of both groups. Additionally, in one study the coxal index (I. ricinus) was calculated as a ratio of tick’s ventral coxal gap and dorsal width of scutum. Tick weight data and coxal indices from Bravecto ^TM -treated and negative-control groups were compared via statistical analysis.

Results

Ticks collected from Bravecto ^TM -treated dogs weighed significantly less (p ≤ 0.0108) than ticks collected from negative-control dogs, and their coxal index was also significantly lower (p < 0.0001). The difference in tick weights was demonstrated irrespective of the tick species investigated (I. ricinus, I. scapularis). At some assessments the mean tick weights of Bravecto ^TM -treated dogs were significantly lower than those of unfed pre-infestation (baseline) ticks. The demonstrated tick-killing efficacy was in the range of 94.6 – 100 %.

Conclusions

Tick weights and coxal indices confirm that a minimal uptake results in a sufficient exposure of ticks to fluralaner (Bravecto ^TM ) and consequently in a potent acaricidal effect.

【 授权许可】

   
2015 Williams et al.

【 图 表 】

Fig. 1.

Fig. 2.

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