R.J.G. Zwijnenberg; P.F. Miller; B. Peters; M.W. Dryden; D. Rugg; L.F. Vettorato; F.O. Silva
Background
Anecdotally veterinarians encounter a rising number of complaints regarding flea product breakdowns. These are often attributed to lack of compliance. However, according to research data, the cat flea is resistant to the greatest number of different categories of insecticides1 and a genetic mutation in the cat flea correlated with reports of low-level fipronil resistance2.
Aims
Investigation and quantification of higher tolerance levels for several commercially available flea products in Australia, Brazil and the USA.
Methods
Australia: collection of flea eggs in households where the same flea product (in this case fipronil) was consistently used. Fleas were bred on "artificial dog" model.
Brazil: Dogs were artificially infected with fleas provided by a Brazilian Parasitology Institute. The treatment with metaflumizone was compared with 3 commercially available products (containing moxidectin, imidacloprid, fipronil and (S)-methoprene) and a control group.
USA: Cats were artificially infected with previously documented fipronil-resistant fleas3. Efficacy of metaflumizone and fipronil/(S)-methoprene was compared with a control group.
Results
Australia: A field strain from Cairns was 27 times more tolerant to fipronil compared to a reference strain. Metaflumizone was equally effective against both strains.
Brazil & USA: Efficacy of 3 commercially available products was significantly shorter compared to metaflumizone.
Conclusions
Confirmation of varying susceptibility of the cat flea for currently available insecticides.
Confirmation of longer efficacy of metaflumizone compared to several commercially available products in several flea strains.
References
1. Rust MK, Dryden MW. The biology, ecology and management of the cat flea. Ann. Rev. Entomol. 1997; 42: 451-473.
2. Bass C. Schroeder I. Turberg A et al. Identification of the Rdl mutation in laboratory and field strains of the cat flea, Ctenocephalis felis (Siphonaptera: Pulicidae). Pest Manag. Sci. 2004; 60: 1157-1162.
3. Payne PA, Dryden MW, Smith V., Ridley RK. Effect of 0.29% w/w fipronil spray on adult flea mortality and egg production of three different cat flea, Ctenocephalides felis (Bouché), stains infesting cats. Vet. Parasit. 2001; 102: 331-340.