Thomas Bach

The effects of an imidacloprid and permethrin combination against developmental stages of Ixodes ricinus ticks

AbstractThe effects of 10% imidacloprid and 50% permenthrin on Ixodes ricinus ticks were studied in-vivo and in-vitro and led to the following significant results: 1.The new combination of imidacloprid and permethrin, applied topically to dogs, resulted in a significant repellent effect, lasting for at least 4 weeks against Ixodes ricinus ticks.2. For dogs resting at tick-contaminated places (thus offering the ticks time for delayed entry into the coat), the acaricidal activity of the new product considerably limits the attachment of ticks. This efficacy is independent from life cycle stages of the I. ricinus tick. 3. The repellency and acaricidal effect after 1 h of exposure reported here is expected to be sufficient to prevent transmission of tick-borne diseases. 4. Together with the fast onset of efficacy against fleas published previously for imidacloprid, the new combination now offers a high level of protection for at least 28 days against fleas and ticks, thus limiting their activities as vectors of diseases.

Efficacy of emodepside plus praziquantel tablets (Profender® tablets for dogs) against mature and immature infections with Toxocara canis and Toxascaris leonina in dogs.

The efficacy of emodepside plus praziquantel tablets (Profender® tablets for dogs) against mature adult, immature adult and larval stages of Toxocara canis and Toxascaris leonina was evaluated in ten randomised, blinded and placebo-controlled dose confirmation studies in naturally or experimentally infected dogs. The tablets were used at the proposed minimum dose of 1 mg emodepside and 5 mg praziquantel per kg body weight. Efficacy was calculated based on worm counts after necropsy. Five studies demonstrated >99% efficacy against mature adult, >92% efficacy against immature adult, >98% efficacy against L4 and >94% efficacy against L3 larval stages of T. canis. Another five studies demonstrated >99% efficacy against mature and immature adult and >95% efficacy against L4 larval stages of T. leonina. No side effects of the treatment were observed. Emodepside plus praziquantel tablets thus provide a comprehensive new treatment option for ascarid infections in the dog.

In vitro and in vivo studies on the effect of a combination containing 10% imidacloprid and 50% permethrin against Ixodes ricinus ticks.

Ticks are, like fleas, among the most common and most important ectoparasites; and huge numbers of ticks are found in most climatic zones of the earth, feeding on the blood of warm-blooded animals and man (Sonenshine 1991, 1993). In recent times, veterinarians and pet owners have increasingly focused their attention on the control of this important ectoparasite. This interest has been fuelled in part by increased public awareness of tick-borne diseases (Lane and Crosskey 1995; Mehlhorn 2001a, 2001b). In Europe and North America, both man and his companion animals, like cats and dogs, are threatened, especially by the bite of species of the genera Ixodes, which may transmit the agents of Lyme borreliosis, ehrlichiosis and different forms of babesiosis (Mehlhorn et al. 1993; Rommel et al. 2000). Thus, prophylactic protection against infestation with ticks is needed to prevent transmission of these pathogens. Here, we consider our companion animal, the dog. The combination of 10% imidacloprid and 50% permethrin (K9 Advantix , trade mark of Bayer AG, Leverkusen, Germany) was recently registered by the EPA for the United States market. The product is indicated for the prevention and treatment of ticks, fleas and mosquitoes and is for monthly use on dogs. The repellent effect of synthetic pyrethroids, known for acaricides, was recently published for permethrin topically applied to dogs (Endris et al. 2000, 2002). In the present study, the effects on repelled life-cycle stages of I. ricinus after short exposure to treated dogs or hair from treated dogs are summarised. Four dogs were treated topically with K9 Advantix at the recommended dosage of 0.1 ml/kg body weight. This corresponds with a dosage of 10 mg imidacloprid/kg and 50 mg permethrin/kg. Four dogs remained untreated as controls. At 7, 14, 21 and 28 days after this treatment, both flanks of one of these dogs were shaved, producing a circular, hairless region of about 20 cm in diameter. The hair was were collected separately and used for in vitro studies.