Introduction

Ixodes ricinus is the most prevalent tick species in dogs and cats in the northern parts of Europe. ProMeris® Duo is a new spot-on ectoparasitic product containing metaflumizone/amitraz that is indicated for the treatment of infestation with various tick species, including Ixodes ricinus, and fleas. In order to evaluate the efficacy of treatment of an existing tick infestation as compared to permethrin (ExSpot®, SPAH), a controlled, randomised and blinded study was conducted under laboratory conditions.

Methods

In a blinded parallel design study, 16 ten to eleven months old dogs (9 male, 7 female) were artificially infested with 25 female and 25 male viable Ixodes ricinus ticks each on Day -2. Based on tick counts on Day -1 and weight, the dogs were randomly allocated to treatment with either ProMeris® Spot-on (minimum 20 mg/kg metaflumizone/20 mg/kg amitraz) or permethrin Spot-on in a 1:1 ratio, using the commercial German products according to SPC recommendations. Subsequently, tick counts were done at 6, 24 and 48 hours post treatment. Per cent reduction relative to Day-1 counts and mean female viable tick counts were compared between treatments using SAS 9.3 Software, ANCOVA.

Results

There were no treatment-related adverse experiences. At 6 hours post treatment, no major effects of treatments were observed in either groups. Mean viable female tick counts were less in ProMeris® Duo treated dogs compared to permethrin animals at 24, but counts were not significantly different (p > 0.05). The counts for dogs treated with ProMeris® Duo were significantly lower than the dogs receiving the permethrin treatment at 48 hours (p=0.0156). At 24 hours, efficacy for the ProMeris Duo dogs was 28.7% and 16.4% for permethrin. By 48 hours after treatment, ProMeris® Duo reduced 75 % of the ticks, while in the permethrin group still more than 66% of the ticks were viable (p=0.0271).

Conclusion

ProMeris® Duo was efficacious in the reduction of Ixodes ricinus ticks in dogs. After 48 hours of treatment, ProMeris® Duo was superior to the treatment with the permethrin spot-on product.