Topical fipronil combo kills Toxascaris worms in cats

Abstract

The efficacy of a novel topical fipronil, (S)-methoprene, eprinomectin and praziquantel combination product (BROADLINE(&#xae;), Merial) was evaluated against adult Toxascaris leonina ascarids in experimentally infected cats in two controlled studies under an identical protocol. For each study, 30 nematode-naive, purpose-bred European Short Hair cats were inoculated orally with approximately 300 larvated T. leonina eggs. Twenty-two and 24 cats, respectively, that were shown to be positive for Toxascaris eggs by pre-treatment faecal examination were subsequently included in the two studies. In each study, the animals were allocated randomly to an untreated (control) group or to a treatment group. The treatment was a novel topical combination: fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4% w/v) and praziquantel (8.3% w/v). Treatment was applied on Day 0 at 0.12 mL/kg bodyweight. For parasite recovery and count, cats were euthanized humanely seven days after treatment and necropsied. All untreated cats harboured adult T. leonina (range, 1-31 nematodes). The treatment provided a high level of efficacy against adult T. leonina in both studies (95.8% and 98.1%, respectively p<0.001). All cats accepted the treatment well based on hourly post-treatment observations for 4h and daily observations thereafter. No adverse experiences or other health problems were observed throughout the studies. Thus the data indicate that this novel combination product will provide a safe and effective treatment against T. leonina in cats.