Investigation of the efficacy of fluralaner spot-on (Bravecto®) against infestations of Ixodes holocyclus on cats

Abstract Background Infestation of cats with the Australian paralysis tick, Ixodes holocyclus continues to be a threat because of the paralysis that can result from attachment of just a single tick. The outcome can be fatal, particularly if tick removal and treatment is not initiated soon after the onset of paralysis. However, there are no published studies to guide veterinarians and owners on preventive measures. A study was therefore initiated to determine the efficacy of a systemically-acting, spot-on formulation of fluralaner (Bravecto®) for cats against existing I. holocyclus infestations, and to investigate the duration of protection following a single administration. Methods Healthy domestic cats, short or long-hair, immunized against holocyclotoxin, were randomly allocated to two groups of 10 cats per group, to receive either a single topically applied fluralaner treatment or no treatment. Fluralaner treatments were administered on Day 0 at a dose rate of 40 mg/kg. All cats were infested with 10 adult unfed female I. holocyclus on Day -1 and on Days 14, 28, 42, 56, 70 and 84. Ticks were assessed at 24 and 48 h after fluralaner treatment and 24, 48 and 72 hours after each subsequent re-infestation. Ticks were counted but not removed at the 24- and 48-h post-challenge assessments and were removed following the 72-h counts. Results The efficacy of fluralaner spot-on against an existing I. holocyclus infestation was 100% at 48 h post treatment. Following re-infestations, efficacy remained at 100% at the 72-h assessments for all challenges from Day 14 to Day 84. Differences between mean live tick counts on treated versus control cats were significant at all time points from the first post-treatment assessment (t-test: t (18) = 23.162; P < 0.0001) through the final challenge on Day 84 (t-test: t (18) = 21.153; P < 0.0001). No treatment-related adverse events were observed and there were no abnormal observations at the product application sites. Conclusions A single treatment of fluralaner spot-on was well tolerated and provided 100% efficacy against I. holocyclus ticks for at least 84 days. Fluralaner spot-on can be a valuable tool to prevent tick infestation in cats, and to control the risk of I. holocyclus-induced paralysis

A single topical fluralaner application to cats and to dogs controls fleas for 12 weeks in a simulated home environment

Abstract Background Fluralaner (Bravecto®, Merck Animal Health, Madison, NJ, USA) is a novel isoxazoline that provides up to 12 weeks flea and tick control when administered orally to dogs. Two assessor-blinded studies, one in dogs, the other in cats evaluated the sustained efficacy of a topical fluralaner formulation against fleas in a simulated home environment (SHE). Methods Animals were ranked and blocked into groups of two using flea counts completed 24 hours following Ctenocephalides felis infestations placed on dogs on Day -64, and on cats on Day -36. Within blocks animals were randomized to a treatment group, 10 animals per group, one group to receive fluralaner spot-on (minimum dose rate for dogs, 25 mg/kg; for cats, 40 mg/kg), the other to be a sham-treated control. Animals were then placed into their SHE, one animal per pen or cage and then infested with 100 C. felis at weekly intervals. Dogs were infested from Day -56 through -21 and cats on Days -28 and -21. Fleas were counted and removed from each dog and cat on Day -1. Study animals were then held in clean pens/cages until treatment on Day 0. One day later, after treatment, all animals were returned to their home environment (SHE). Additional 50-flea challenges were placed on each animal on Days 22, 50 and 78. Fleas were counted and replaced on all animals on Day 1 and weekly thereafter for 12 weeks. Results Arithmetic mean counts in control-group animals exceeded 10 fleas at all post-treatment assessments except on Days 1, 7 and 14. All control-group animals remained infested at each assessment from Day or 28 through Day 84, thereby validating the challenge methodology. Fluralaner efficacy was 100% on all occasions except for 2 fleas found on 1 dog on Day 1, and 3 fleas on 1 dog on Day 14. One flea was recovered from 1 fluralaner treated cat on Day 1. There were no treatment-related adverse events. Conclusion A single application of a topical formulation of fluralaner is well tolerated and highly effective in the prevention of flea infestations of dogs and cats throughout the 12 weeks following treatment

Efficacy of indoxacarb applied to cats against the adult cat flea, Ctenocephalides felis, flea eggs and adult flea emergence

Background: A study was conducted to evaluate the effect of indoxacarb applied to cats on adult cat fleas, Ctenocephalides felis, flea egg production and adult flea emergence. Methods: Sixteen cats were selected for the study and allocated to two treatment groups. Eight cats were treated with a 19.5% w/v topical spot-on solution of indoxacarb on day 0 and eight cats served as untreated controls. Each cat was infested with 50 fleas on Days −2, 7, 14, 21, 28, 35 and 42. On Days 1, 2, and 3, and at 2 and 3 days after each post treatment reinfestation flea eggs were collected from the pan under each cat cage. Eggs were counted and viability assessed by evaluating adult flea emergence 28 days after egg collection. Three days after treatment or infestation, each cat was combed to remove and count live fleas. Results: Treatment with indoxacarb provided 100% efficacy following infestations on day −2, 7, 14, 21 and 28 and efficacy was 99.6% following infestations on days 35 and 42. Egg production from indoxacarb treated cats was reduced by 99.9% within 72 hours of treatment. For subsequent infestations no eggs were produced from treated cats from day 8 through day 30. Egg production was still reduced by ≥95.8% through day 45. Indoxacarb treatment also reduced adult flea emergence from eggs for 5 weeks after treatment. The combination of reduction in egg numbers and egg viability from indoxacarb treated cats reduced predicted flea emergence by 100% from days 2 – 31 and 99.9%, 100%, 96.4% and 99.0% on days 37, 38, 44 and 45, respectively. Conclusions: A topical spot-on formulation of indoxacarb provided ≥99.6% efficacy against flea infestations on cats for 6 weeks following a single treatment. Indoxacarb also eliminated or markedly reduced egg production for the entire evaluation period and reduced the viability of the few eggs that were produced from Day 1 through Day 38. Given indoxacarb’s effect on adult fleas, egg production and egg viability; this formulation can interrupt flea reproduction on treated cats for at least 6 weeks after treatment

Efficacy and safety assessment of a water-soluble formulation of fluralaner for treatment of natural Ornithonyssus sylviarum infestations in laying hens

Abstract Background Northern fowl mite, Ornithonyssus sylviarum (Canestrini & Fanzago, 1877), infestations can stress birds, impairing welfare and causing substantial economic losses. A study was undertaken to determine the efficacy of an ectoparasiticide solution (fluralaner) for oral administration in the treatment of mite-infested hens. Methods Clinically healthy, naturally mite-infested laying hens (n = 132), approximately 32 weeks of age, were ranked by Day -9 mite vent counts and randomized among 12 study pens, each to hold one of four treatment groups. Three groups received fluralaner-medicated water by oral gavage at dose rates of 0.25, 0.5 or 1.0 mg/kg on Days 0 and 7; one group was an untreated control (three pens for each group). Five naturally infested untreated birds were included in each pen to act as mite-infested source birds. Thus each pen, treated and control, had six non-source birds for assessment of efficacy, plus five source birds to provide ongoing challenge. Primary efficacy assessments were based on mean O. sylviarum vent counts from non-source birds in the control and treated group pens on Days 1, 2, 6, 8, 12, 15, 19, 22 and 26. Results Source-birds maintained infestations throughout the study, validating the challenge to study birds. On Days 1 through 22, mean control group mite counts were significantly greater than those of the treated groups (P ≤ 0.013). Relative to the control group, mean O. sylviarum counts were reduced by at least 90% from Day 6 through Days 19, 22 and 22 in the fluralaner 0.25, 0.5 and 1.0 mg/kg groups, respectively. On Day 19, mean mite counts were lower in the 0.5 and 1.0 mg/kg groups compared with the 0.25 mg/kg group (P ≤ 0.018), and in the 1.0 mg/kg compared with the 0.5 mg/kg group (P = 0.014). There were no adverse events in treated birds. Conclusions A fluralaner solution administered twice by gavage to laying hens with a one-week between-treatment interval was safe and effective in quickly controlling O. sylviarum infestations despite continuous challenge from infested birds. By eliminating mites, this fluralaner solution has the potential to improve bird health and productivity, and to eliminate the burden of topical pesticide application

Study on soil-water characteristic curves in the profiles of collapsing walls of typical granite Benggang in southeast China

Benggang with steep collapsing walls is one of the worst soil erosion problems in South China. The collapse of walls is the most critical process in Benggang development. This is mainly due to the soil water properties. The soil water characteristic curve (SWCC) is a key indicator for analyzing soil moisture, but the SWCC and its mechanism of influence in collapsing walls remain obscure. A pressure plate meter was used for drying experiments to research the SWCCs of undisturbed soils of five layers (from top to bottom: red soil layer, transition layer I, sand soil layer, transition layer II and detrital layer) of two typical collapsing walls. The van Genuchten (VG) model can be fitted to the SWCCs for different layers (NSE ≥ 0.90). With increasing soil depth, the parameters a and θs first decreased and then increased, the parameters n first increased and then decreased, θr declined as the soil depth increased. These findings illustrate that soil water holding capacity decreases with increasing soil depth. The bottom of the soil is weak in water retention and water can easily reach saturation, resulting in a decline in soil stability, thus promoting soil collapse and finally inducing upper soil collapse. Furthermore, gravel content and particle morphology are factors that should not be neglected for SWCCs. The results of this study provide a theoretical basis for understanding the process of wall collapse in Benggang landforms in South China

Evaluation of indoxacarb and fipronil (s)-methoprene topical spot-on formulations to control flea populations in naturally infested dogs and cats in private residences in Tampa FL. USA

Background: A study was conducted to evaluate and compare the effectiveness of two different spot-on topical flea products to control flea infestations on naturally infested dogs and cats in Tampa, FL USA. Methods: Thirty-two dogs and 3 cats with natural flea infestations living in 18 homes were treated topically with a 19.53% w/w spot-on formulation of indoxacarb. Another thirty dogs and 2 cats living in 19 different homes were treated topically with either fipronil (9.8% w/w)/(s)-methoprene (8.89% w/w) or fipronil (9.8% w/w)/(s)-methoprene (11.8% w/w), respectively. All products were applied according to label directions by study investigators on day 0 and again between days 28 and 30. Flea populations on pets were assessed using visual area counts and premise flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, 28–30, 40–45, and 54–60. Results: A single application of the indoxacarb or fipronil (s)-methoprene formulations reduced flea populations on pets by 97.8% and 85.5%, respectively within 7 days. One month (28–30 days) after treatment the indoxacarb and fipronil (s)-methoprene formulations reduced on-animal flea burdens by 95.0% and 49.5%, respectively. Following two monthly applications of either the indoxacarb or fipronil (s)-methoprene formulations, pet flea burdens were reduced by 99.1% and 54.8%, respectively, by days 54 – 60. At the end of the two month study, 77.1% and 15.6% of the dogs and cats in the indoxacarb and fipronil (s)-methoprene treatment groups, respectively were flea free. Flea numbers in the indoor-premises were markedly reduced in both treatment groups by days 54–60, with 97.7% and 84.6% reductions in intermittent-light flea trap counts in the indoxacarb and fipronil (s)-methoprene treatment groups, respectively. Conclusions: This in-home investigation conducted during the summer of 2013 in subtropical Tampa, FL, is the first published U.S field investigation of the indoxacarb topical formulation. The indoxacarb formulation was able to effectively control flea populations in heavily flea infested pets and homes. The efficacy achieved by the fipronil (s)-methoprene formulation against flea infestations on these pets was lower than in previous investigations using the same study design

Erratum to: Efficacy of fluralaner flavored chews (Bravecto®) administered to dogs against the adult cat flea, Ctenocephalides felis felis

Citation: Dryden, M. W., Smith, V., Bennett, T., Math, L., Kallman, J., Heaney, K., & Sun, F. S. (2015). Efficacy of fluralaner flavored chews (Bravecto (R)) administered to dogs against the adult cat flea, Ctenocephalides felis felis and egg production (vol 8, 364, 2015). Parasites & Vectors, 8, 2. doi:10.1186/s13071-015-1014-zUnfortunately, the original version of this article [1] contained a mistake. Table 2 (table 1 here) was incorrect as it inadvertently included a duplication of data presented in Table 1. Table 2 has been corrected in the original article and is included correctly below