Efficacy in cats of a novel topical combination of fipronil, (S)-methoprene, eprinomectin, praziquantel, against induced infestations of Echinococcus multilocularis.

Although foxes are the main reservoir of Echinococcus multilocularis, it is recognized that dogs and cats also may become infected. In cats the infection and egg production rates are usually low. Nevertheless, cats are a potential source of transmission of E. multilocularis. Due to the high human medical significance of E. multilocularis infection, it is important in endemic areas that owned cats are dewormed regularly. This paper presents the efficacy results of a new topical formulation, Broadline(®) (Merial) tested against E. multilocularis infection in cats. Two blinded laboratory studies were conducted to evaluate this novel topical combination of fipronil, (S)-methoprene, eprinomectin, and praziquantel against E. multilocularis. In each study, purpose-bred cats were assigned randomly to two treatment groups of 10 cats each: one untreated control group and one group treated at the minimum therapeutic dose of 0.12 mL/kg bodyweight to deliver 10mg fipronil, 12 mg (S)-methoprene, 0.5mg eprinomectin and 10mg praziquantel/kg bodyweight. The cats were inoculated orally with E. multilocularis protoscolices, 22 or 23 days before treatment. Based on necropsy and intestinal worm count, 8 or 11 days after treatment, the two studies confirmed 100% efficacy of Broadline(®) against adult E. multilocularis.

Efficacy of fipronil, amitraz and (S)-methoprene combination spot-on for dogs against adult dog fleas (Ctenocephalides canis, Curtis, 1826).

A novel spot-on formulation combining fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) was evaluated in adult Beagle dogs in a study to determine its adulticidal efficacy against the dog flea (Ctenocephalides canis, Curtis, 1826). Sixteen dogs were randomly allocated to treatment groups: 8 dogs served as untreated controls, and 8 dogs were treated once. Treatment consisted of applying a new combination formulation to deliver at least 6.7mg fipronil/kg body weight (bw), 8.0mg amitraz/kg bw, and 6.0mg (S)-methoprene/kg bw. The combination was designed to enhance the efficacy against ticks of the original fipronil/(S)-methoprene combination. Each dog was infested with 100 adult unfed dog fleas within 24h prior to treatment and then at weekly intervals for 8 weeks after treatment. At 24h after treatment or after each subsequent infestation, each dog was combed thoroughly to remove live fleas to be counted. A single treatment with CERTIFECT provided excellent knock-down of fleas within 24h after treatment and controlled re-infestations for up to 7 weeks (efficacy ≥96.5%, p<0.05).

The prevention of transmission of Babesia canis canis by Dermacentor reticulatus ticks to dogs using a novel combination of fipronil, amitraz and (S)-methoprene.

Four groups of seven dogs were treated topically with a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT™, Merial Limited, GA, USA) on 28, 21, 14 and 7 days prior to tick infestation, respectively and acaricidal efficacy and transmission blocking compared with an untreated control group (seven dogs). All dogs were infested with adult Dermacentor reticulatus ticks harbouring Babesia canis canis. Babesia canis canis was transmitted by D. reticulatus to all seven untreated control dogs, confirmed following demonstration of clinical signs, by the detection of B. canis parasites in thin blood smears and B. canis canis PCR-RLB DNA assay on blood and the development of B. canis canis antibody titres by 14-21 days after tick infestation. The majority of treated dogs remained sero-negative for 42 days after infestation. Therefore, the treatment of dogs with CERTIFECT applied up to 28 days prior to infestation with D. reticulatus harbouring B. canis canis, successfully prevented the development of clinical signs of canine babesiosis.