Efficacy of a slow-release imidacloprid (10%)/flumethrin (4.5%) collar for the prevention of canine leishmaniosis.

BACKGROUND: The efficacy of a slow-release insecticidal and repellent collar containing 10% imidacloprid and 4.5% flumethrin (Seresto, Bayer Animal Health) in preventing Leishmania infantum infection was evaluated in a large population of dogs living in a hyper-endemic area of Sicily (Italy). METHODS: A total of 219 dogs, negative for L. infantum were enrolled in a multicentre, controlled study. Dogs were divided into two homogeneous groups, defined as G1 (n = 102) and G2 (n = 117). Before the start of the sand fly season, dogs in G1 were treated with the collar while animals in G2 were left untreated, serving as negative controls. Dogs were serially sampled on day D90, D180, D210 and D300 in order to assess Leishmania infection by IFAT, PCR on skin (D210-D300) and bone marrow (D300) and cytology on bone marrow aspirate (D300). RESULTS: Three dogs (2.9%) in G1 and 41 (40.2%) in G2 became positive for L. infantum in at least one of the diagnostic tests employed in the study. The number of seropositive dogs in G2 increased in the course of the study from 15 (D90) to 41 (D300), with some of them also positive in other diagnostic tests. Eight (19.6%) of the seropositive dogs in G2 showed an increase in antibody titers ranging from 1:160 to 1:1,280. At the last follow-up, some of dogs in G2 displayed overt clinical signs suggestive of leishmaniosis. The mean incidence density rate at the final follow-up was 4.0% for G1 and 60.7% for G2, leading to a mean efficacy of the collar in protecting dogs at both sites of 93.4%. CONCLUSIONS: The slow-release collar tested in this study was shown to be safe and highly effective in preventing L. infantum infection in a large population of dogs. Protection conferred by a single collar (up to eight months) spanned an entire sand fly season in a hyper-endemic area of southern Italy. The regular use of collars, at least during the sand fly season, may represent a reliable and sustainable strategy for the prevention of leishmaniosis in dogs living in or travelling to an endemic area.

Efficacy of a combination of 10% imidacloprid and 4.5% flumethrin (Seresto®) in slow release collars to control ticks and fleas in highly infested dog communities.

BACKGROUND: Dog communities living in kennels are at high risk of being infected by ticks and fleas. In spite of the indubitable efficacy of several topical ectoparasiticides registered for the control of ectoparasites in dogs, the short period of action and the price of these products limit their use in dog communities. This paper reports on the efficacy of imidacloprid/flumethrin slow release collars to cure dogs highly infested with ectoparasites and to prevent infestations for 8 months in a refuge with a history of unsuccessful environmental treatments. METHODS: A total of 82 dogs were collared with slow release collars containing a formulation of imidacloprid 10% / flumethrin 4.5%. Dogs were followed-up for ectoparasite presence after 2, 7 and 14 days and thereafter biweekly up to 90 days. Furthermore, dogs were examined for ectoparasites whilst replacing collars 8 months after their application. RESULTS: At the time of treatment 79 (96.3%) out of 82 included dogs were heavily infested by ticks and 53 (68.8%) out of the 77 combed dogs were infested by fleas. Tick infested dogs had an estimated mean intensity of 46.9 (± 65.7), while flea infested animals had a load between 20 and 50 fleas. In addition, some of the flea infested dogs (18.9%) were presenting signs of flea allergic dermatitis (FAD). Two days after treatment, 49 (60.5%) and 9 (11.7%) dogs were still infested by live ticks and fleas, respectively. However, the mean intensity of ticks decreased to 3.5 (± 4.3) with a reduction of 92.5%. Except for sporadic cases, no attached ectoparasites were found on dogs from the day 14 visit until the end of the investigation. Cases of FAD resolved without any other treatment within 30 days. CONCLUSIONS: Ticks and fleas represent a constant hazard for dog populations. Therefore, in particular settings, such as dog refuges, sustainable and long-term strategies to control ectoparasite infestations are needed. Based on the observed evidence of efficacy, long-term duration and safety, the imidacloprid/flumethrin slow release collars can be regarded as an efficacious and sustainable means for ectoparasite control and for treatment of FAD in high-risk dog communities.