Laboratory assessment of the anti-feeding effect for up to 12 months of a slow release deltamethrin collar (Scalibor®) against the sand fly Phlebotomus perniciosus in dogs.

BACKGROUND: Leishmaniosis/leishmaniasis consists of a wide group of diseases, caused by different Leishmania species and having different hosts. Leishmaniosis caused by Leishmania infantum, a disease primarily of dogs and humans, occurs after susceptible hosts are exposed to the feeding behavior of infected sand flies. A one-year laboratory study in dogs was designed to determine the 364-day anti-feeding efficacy of a slow release deltamethrin collar against the sand fly P. perniciosus, a common host of L. infantum in the Mediterranean basin. METHODS: In this assessor-blinded study, 16 Beagle dogs were randomized into two groups using P. perniciosus engorgement rates from a Day -7 challenge. On Day 0, dogs in Group 1 received a placebo collar, while dogs in Group 2 received a deltamethrin collar (Scalibor® Protector Band). All dogs were caged, sedated and then exposed for 1 h to 85 (± 10) female and 15 (± 5) male P. perniciosus on Day 7 and every 28 days through Day 364. All flies, alive and dead, were aspirated from cages and from dogs, immediately counted and then frozen for assessment of blood engorgement. Anti-feeding efficacy was determined by comparing the arithmetic means of engorged female flies (alive, dead and moribund) in the deltamethrin group to the control group means. Insecticidal efficacy at the time flies were retrieved was assessed by comparisons between groups of mean live female fly counts. RESULTS: In the deltamethrin group, relative to the control group, there was a significant reduction in arithmetic mean numbers of engorged P. perniciosus of 94-98% from Day 7 through Day 364. On Day 28, in the treated group relative to the control group, there was a 74% reduction in mean live fly counts, with between-group differences significant from Days 7 through 196, although insecticidal activity remained less than 50% from Day 56. CONCLUSION: Deltamethrin collar application to dogs reduced sand fly feeding by ≥ 94%, relative to unprotected control dogs, for 364 days. Thus, one collar applied to a dog can prevent or reduce the risk of sand fly transmission of Leishmania for one full year.

Efficacy of fluralaner against Otodectes cynotis infestations in dogs and cats.

BACKGROUND: The efficacy of fluralaner for the treatment of Otodectes cynotis infestations in dogs and cats was evaluated after oral (dogs) or topical administration (dogs and cats). Twenty-four dogs and sixteen cats were experimentally infested with O. cynotis and randomly allocated to equal sized groups (n = 8/group). Dog groups were treated once, either orally with fluralaner at a minimum dose of 25 mg/kg body weight, topically with fluralaner at a dose of 25 mg/kg body weight or topically with saline solution (control). Cat groups were treated once, either topically with fluralaner at a dose of 40 mg/kg body weight or topically with saline solution. Ears of all animals were examined otoscopically for live visible mites and the amount of debris and cerumen before, and 14 and 28 days after treatment. Twenty-eight days after treatment, animals were sedated and both ears were flushed to obtain the total number of live mites per animal. The efficacy was calculated, based on the results of the ear flushing, by comparing mean live mite counts in the fluralaner treated groups versus the saline solution treated group. RESULTS: A single topical treatment of cats with fluralaner reduced the mean mite counts by 100% (P < 0.001) at 28 days after treatment. Similarly, a single oral or topical treatment of dogs with fluralaner reduced the mean mite counts by 99.8% (P < 0.001) at 28 days after treatment. Cats treated topically with fluralaner had no mites visible during otoscopic examination at either 14 or 28 days after treatment. All dogs treated orally or topically with fluralaner had no mites visible during otoscopic examination at 28 days after treatment. At 14 days after treatment, only 1-2 mites were visible in three dogs (oral treatment: 2 dogs, topical treatment: 1 dog). All fluralaner-treated animals showed improvement in the amount of cerumen exudation compared with observations performed before treatment. No treatment related adverse events were observed in any dogs or cats enrolled in these studies. CONCLUSIONS: In this study, fluralaner administered topically to cats and orally or topically to dogs was highly effective against Otodectes cynotis mite infestations.

Efficacy of fluralaner administered either orally or topically for the treatment of naturally acquired Sarcoptes scabiei var. canis infestation in dogs.

BACKGROUND: The efficacy of fluralaner, formulated as a chewable tablet (Bravecto™) or topical solution (Bravecto™ Spot-on Solution), was evaluated against naturally acquired Sarcoptes scabiei var. canis infestation in dogs. METHODS: The study was performed in privately-owned dogs naturally infested with S. scabiei var. canis. All dogs living in the same household as the infested dog were enrolled into one of 3 groups (2 fluralaner treated and 1 negative control). All dogs within one household were administered the same treatment, with one dog per household included in further observations and assessments. In total, 29 dogs confirmed positive for sarcoptic mange were included. On Day 0, all dogs in group 1 (n = 9) were treated once orally with fluralaner at a minimum dose of 25 mg/kg body weight; all dogs in group 2 (n = 11) were treated once topically with fluralaner at a dose of 25 mg/kg body weight; and dogs in group 3 (n = 9) were treated once topically with saline solution. Sarcoptes scabiei var. canis mites on each dog were counted before treatment and at 4 weeks after treatment in deep skin scrapings (~4 cm(2)) from 5 different body areas. Clinical signs of infestation (i.e. erythematous papules; casts, scales and crusts; body areas with hair loss) and pruritus were recorded at the same time points. RESULTS: Single oral or topical treatment with fluralaner resulted in a 100 % reduction in mite counts post-treatment (group 1: P = 0.0009 and group 2: P = 0.0011). Resolution of clinical signs at four weeks post-treatment was variable, with improvement observed for erythematous papules, casts and crusts, and pruritus. All fluralaner treated dogs showed an improvement in overall hair re-growth compared with pre-treatment observations. CONCLUSION: Fluralaner administered either orally or topically to naturally infested dogs eliminates Sarcoptes scabiei var. canis mites and improves clinical signs over a 4-week observation period.

Efficacy of orally administered fluralaner (Bravecto™) or topically applied imidacloprid/moxidectin (Advocate®) against generalized demodicosis in dogs.

BACKGROUND: This laboratory study compared the efficacy of Bravecto™ (fluralaner), formulated as a chewable tablet, with the efficacy of Advocate® (imidacloprid/moxidectin), formulated for topical administration, against naturally acquired generalized demodicosis in dogs. METHODS: Sixteen dogs, all diagnosed with generalized demodectic mange, were randomly allocated to two equal groups. Bravecto™ chewable tablets were administered once orally at a minimum dose of 25 mg fluralaner/kg body weight to one group of dogs, while the second group was treated topically on three occasions at 28-day intervals with Advocate® at a minimum dose of 10 mg imidacloprid/kg body weight and 2.5 mg moxidectin/kg body weight. Mites were counted in skin scrapings and demodectic lesions were evaluated on each dog before treatment and at 28-day intervals thereafter over a 12 week study period. Deep skin scrapings (~4 cm(2)) were made from the same five sites on each dog at each subsequent examination. RESULTS: After single oral administration of Bravecto™ chewable tablets, mite numbers in skin scrapings were reduced by 99.8% on Day 28 and by 100% on Days 56 and 84. Mite numbers in the dogs treated topically on three occasions at 28-day intervals with Advocate® were reduced by 98.0% on Day 28, by 96.5% on Day 56 and by 94.7% on Day 84. Statistically significantly (P ≤ 0.05) fewer mites were found on Days 56 and 84 on the Bravecto™ treated dogs compared to Advocate® treated dogs. A marked decrease was observed in the occurrence of erythematous patches, crusts, casts and scales in the dogs treated with Bravecto™ and in the occurrence of erythematous patches in the dogs treated with Advocate®. With the exception of one dog in each treated group, all dogs exhibited hair regrowth ≥ 90% at the end of the study in comparison with their hair-coat at study start. CONCLUSIONS: Single oral administration of Bravecto™ chewable tablets is highly effective against generalized demodicosis, with no mites detectable at 56 and 84 days following treatment. In comparison, Advocate®, administered three times at 28-day intervals, is also highly effective against generalized demodicosis, but most dogs still harboured mites at all assessment time points. Both treatments resulted in a marked reduction of skin lesions and increase of hair re-growth 12 weeks after the initial treatment.

Anti-feeding efficacy of Activyl® Tick Plus topical treatment of dogs against Phlebotomus perniciosus.

BACKGROUND: Topical permethrin treatment is known to prevent feeding of sandflies on dogs. This study investigated the anti-feeding efficacy and the immediate insecticidal efficacy (knock-down effect) of topical treatment of dogs with a new commercially available combination of indoxacarb and permethrin (Activyl® Tick Plus), compared with a negative control. METHODS: Sedated dogs were individually exposed to unfed female sandflies in a darkened chamber for one hour 2, 7, 14, 21 and 29 days after treatment. Mean fly feeding and survival rates in the two groups after one hour of exposure were used to calculate the anti-feeding efficacy and the knock-down effect, respectively. RESULTS: On Days 2, 7, 14, 21 and 29 post treatment, the anti-feeding efficacy was 99, 98, 96, 88 and 84% based on geometric means. The mean number of fed sandflies in the treated group was significantly lower than in the control group mean at every evaluation time point. The knock-down effect, measured at one hour after exposure of the flies to treated dogs, was 32, 27, 9, 0 and 4% based on geometric means, at the same time points. The number of dead flies was significantly higher in the treated group on Days 2 and 7 post-treatment. No adverse effects of treatment were observed at any time during the study. CONCLUSIONS: Activyl® Tick Plus treatment of dogs provided a high anti-feeding efficacy against Phlebotomus perniciosus from 2 to 21 days post treatment, with continuing significant anti-feeding to 29 days post-treatment, and was well tolerated. Some knock-down effect following one hour of exposure of flies to treated dogs was observed in the first week after treatment.