BACKGROUND: The studies reported here were conducted to ascertain the efficacy of imidacloprid/flumethrin
incorporated in a slow-release matrix collar, against infestations of dogs by fleas, ticks, mites and lice. Efficacy was
evaluated against the flea Ctenocephalides felis felis, the ticks Rhipicephalus sanguineus, Ixodes ricinus, Ixodes
scapularis, Dermacentor reticulatus and Dermacentor variabilis, the mite Sarcoptes scabiei and the biting louse
METHODS: Groups of collar-treated dogs (n = 7–10) were infested with fleas and/or ticks at monthly intervals at least,
over a period of up to 8 months. Efficacy against fleas was evaluated 24 to 48 h after treatment and 24 h after each
re-infestation. Efficacy against ticks was evaluated at 48 h (acaricidal), 6 h (repellent) and 48 h (sustained) after
infestation. The effect of regular shampooing or immersion in water on the efficacy of the collars was also tested.
Efficacy against flea larvae was assessed by incubating blanket samples after dog contact with viable flea eggs.
Effectiveness against lice and mites was evaluated after treatment of naturally infested animals. With the exception
of the mites, efficacy was calculated by comparison with untreated negative control groups.
RESULTS: Efficacy against fleas (24 h) generally exceeded 95%, and against flea larvae it exceeded 99% for 8 months.
Sustained acaricidal (48 h) efficacy, covering a period of 8 months was 100% against I. ricinus, starting 2 days after
treatment (in vivo), and 100% against I. scapularis (in vitro), above 97% against R. sanguineus, generally above 97%
against D. reticulatus and above 90% for D. variabilis.
Repellent (6 h) efficacy 2 days after treatment and continuing for 8 months was consistently 100% against I. ricinus,
and above 90% against R. sanguineus.
Regular shampooing affected efficacy against fleas and ticks to a lesser extent than regular immersion in water.
The collars eliminated Trichodectes canis within 2 days and Sarcoptes scabiei within 3 months.
CONCLUSION: The rapid insecticidal and acaricidal properties of the medicated collars against newly-acquired
infestations of fleas and ticks and their sustained high levels of preventive efficacy have been clearly shown.
Consequently they have the potential to prevent the transmission of vector-borne diseases and other conditions
directly associated with infestation throughout an entire season of parasite abundance.
DS, EMK, JJF and WD designed the study design and protocols and JJF and
EMK carried out the studies. DS, JJF, EMK and WD and IGH compiled and
analysed the data. IGH was responsible for the first draft of the manuscript, which was then substantially revised by all authors. All authors read and
approved the final manuscript.