Biology, Treatment, and Control of Flea and Tick Infestations

ArticleinVeterinary Clinics of North America Small Animal Practice 39(6):1173-200, viii · November 2009with151 Reads
DOI: 10.1016/j.cvsm.2009.07.001 · Source: PubMed
Abstract
Flea and tick infestations are common and elimination can be expensive and time consuming. Many advances in control of fleas can be directly linked to improved knowledge of the intricacies of flea host associations, reproduction, and survival in the premises. Understanding tick biology and ecology is far more difficult than with fleas, because North America can have up to 9 different tick species infesting cats and dogs compared to 1 primary flea species. Effective tick control is more difficult to achieve than effective flea control, because of the abundance of potential alternative hosts in the tick life cycle. Many effective host-targeted tick control agents exist, several of which also possess activity against adult or immature fleas and other parasites.
    • "Historically, insecticide impregnated flea collars likely failed to control flea infestations because their residual speed of flea kill was too slow to prevent fleas from producing viable eggs [3, 8, 11]. Ctenocephalides f. felis can initiate egg production within 24–48 h after females acquire a host and take their first blood meal [20, 21]. Therefore, if a residual insecticide cannot kill newly acquired fleas within 24 h, egg production could be maintained and the infestation will be sustained generation upon generation. "
    [Show abstract] [Hide abstract] ABSTRACT: Background This controlled laboratory study was designed to evaluate the efficacy of the 10 % imidacloprid/4.5 % flumethrin collar (Seresto®, Bayer Animal Health) against fleas (Ctenocephalides f. felis) on cats, when compared to fipronil (9.8 %w/w)/(s)-methoprene (11.8 % w/w) topical spot-on formulation (Frontline® Plus for Cats and Kittens, Merial). Methods Thirty cats were randomized into three groups of ten animals based on pre-treatment flea counts: Group 1: imidacloprid/flumethrin collar; Group 2: fipronil/(s)-methoprene topical spot-on and Group 3: non-treated controls. The imidacloprid/flumethrin collars were applied one time on Day 0, while the fipronil/(s)-methoprene spot-on was administered every 30 days from Day 0 through Day 210. Cats were infested with 100 fleas on study days 0, 7, 14, 29, 59, 89, 119, 149, 179, 209 and 239. All flea counts were conducted by combing to remove fleas on post-treatment days 2, 8, 15, 30, 60, 90, 120, 150, 180, 210 and 240. Results The efficacy of the imidacloprid/flumethrin collar ranged from 98.2 to 100 % for eight months. The efficacy of fipronil/(s)-methoprene spot-on ranged from 68.2 to 99.9 %. Efficacy was < 85 % for fipronil/(s)-methoprene on Days 90, 150 and 210. The flea counts in both treatment groups were significantly fewer than those in the non-treated control group at every post-treatment study day (P < 0.0001). In addition, there were significantly fewer fleas in the imidacloprid/flumethrin collar group when compared to the fipronil/(s)-methoprene group on Days 90, 150 and 210 (P < 0.0001). Conclusions This study demonstrated that the imidacloprid/flumethrin collar (Seresto®, Bayer Animal Health) maintained excellent ( > 98.2 %) efficacy against fleas on cats for the entire 8 month study. Monthly applications of fipronil/(s)-methoprene (Frontline® Plus for Cats and Kittens, Merial) generally had high, but variable (68.2 to 99.9 %) efficacy over the course of the eight month study. Based on the very high residual efficacy achieved by the imidacloprid/flumethrin collar in this study, veterinarians should expect that this collar will control and eliminate existing flea infestations on cats and in their in-home premises as long as every flea infested host is treated.
    Full-text · Article · Dec 2016
    • "The brown dog tick is unusual in that it is commonly found indoors. Thus, its geographic range is quite extensive as though R.sanguineus sensu lato is generally considered to be a tropical tick and relatively cold intolerant, it persists in temperate regions by infesting kennels and homes [2]. Unfed larvae, nymphs and adults can survive for many months off the host but the life cycle can be completed in as little as 2–3 months. "
    [Show abstract] [Hide abstract] ABSTRACT: Background: The brown dog tick, Rhipicephalus sanguineus sensu lato, commonly infests dogs globally, is the major vector of the pathogen that causes canine monocytic ehrlichiosis and also transmits Babesia vogeli. A rapid speed of kill of a parasiticide is essential to reduce the direct deleterious effects of tick infestation and the risk of tick-borne pathogen transmission. The speed of kill of a novel orally administered isoxazoline parasiticide, sarolaner (Simparica™), against R. sanguineus sensu lato on dogs was evaluated and compared with afoxolaner (NexGard®) for 5 weeks after a single oral dose. Methods: Based on pretreatment tick counts, 24 dogs were randomly allocated to oral treatment with either placebo, or label doses of sarolaner (2-4 mg/kg) or afoxolaner (2.5-6.8 mg/kg). Dogs were examined and live ticks counted at 8, 12, and 24 h after treatment and subsequent re-infestations on Days 7, 14, 21, 28, and 35. Efficacy was determined at each time point relative to counts for placebo dogs. Results: There were no adverse reactions to treatment. Based on geometric means, sarolaner provided >94 % efficacy within 8 h of treatment, and >99 % after 12 and 24 h. Against subsequent weekly re-infestations of ticks, sarolaner achieved ≥91.7 % efficacy (based on geometric means) to Day 35 at 24 h. Sarolaner significantly reduced tick counts versus placebo on Days 0 and 28 at 8 h (P ≤ 0.0390), on Days 0 to 14 and 28 at 12 h (P ≤ 0.0142), and on all days at 24 h (P < 0.0001). By comparison, tick counts for afoxolaner were significantly lower than placebo at 8 h on Days 0 and 28 (P ≤ 0.0117), at 12 h on Day 0 only (P < 0.0001), and on all days at 24 h (P ≤ 0.0078). Significantly more live ticks were recovered from afoxolaner-treated dogs than from sarolaner-treated dogs at 8 and 12 h after treatment (P ≤ 0.0286), at 12 h after re-infestation on Days 7 and 28 (P ≤ 0.04630), and at 24 h after re-infestations from Day 7 to Day 35 (P ≤ 0.0119). At 24 h, efficacy (based on geometric mean counts) of afoxolaner was less than 90 % from Day 7 onwards, and declined to less than 45 % by Day 35, while efficacy for sarolaner was >90 % for 35 days. Conclusions: In this controlled laboratory evaluation, sarolaner had a faster speed of kill against R. sanguineus sensu lato than afoxolaner. The rapid and consistent kill of ticks within 24 h after a single oral dose of sarolaner over 35 days indicates that this treatment will provide highly effective and reliable control of ticks over the entire treatment interval and should reduce the risk of tick-borne pathogen transmission.
    Full-text · Article · Dec 2016
    • "Ticks are viewed by pet owners and veterinarians as both a nuisance and a threat; heavy and prolonged tick infestations can cause anemia, especially in young or small dogs [1], and they are vectors of pathogens of domestic and wild animals, as well as of people [2]. The lone star tick, Amblyomma americanum, is the vector of Ehrlichia chaffeensis and Ehrlichia ewin- gii [3, 4], to dogs and man, which cause monocytic and granulocytic ehrlichiosis, respectively. Borrelia lonestari, a probable cause of erythema migrans in man, has also been detected in A. americanum ticks using DNA amplification techniques [5]. "
    [Show abstract] [Hide abstract] ABSTRACT: Background: The lone star tick, Amblyomma americanum, infests dogs and cats in North America and is the vector of the pathogens that cause monocytic and granulocytic ehrlichiosis in dogs and humans. A parasiticide's speed of kill is important to minimize the direct and deleterious effects of tick infestation and especially to reduce the risk of transmission of tick-borne pathogens. In this study, speed of kill of a novel orally administered isoxazoline parasiticide, sarolaner (Simparica(™) chewable tablets), against A. americanum on dogs was evaluated and compared with afoxolaner (NexGard(®)) for 5 weeks following a single oral dose. Methods: Based on pretreatment tick counts, 24 dogs were randomly allocated to treatment with sarolaner (2 to 4 mg/kg), afoxolaner (2.5 to 6.8 mg/kg) or a placebo. Dogs were examined and live ticks counted at 8, 12, and 24 h after treatment and subsequent re-infestations on Days 7, 14, 21, 28, and 35. Efficacy was determined at each time point relative to counts for placebo dogs. Results: A single oral dose of sarolaner provided 100 % efficacy within 24 h of treatment, and consistently provided >90 % efficacy against subsequent weekly re-infestations with ticks to Day 28. Significantly more live ticks were recovered from afoxolaner-treated dogs than from sarolaner-treated dogs at 24 h after infestation from Day 7 through Day 35 (P ≤ 0.0247). At 24 h, efficacy of afoxolaner declined to less than 90 % from Day 14 to the end of the study. There were no adverse reactions to treatment. Conclusions: In this controlled laboratory evaluation, sarolaner had a faster speed of kill against A. americanum ticks than afoxolaner. The rapid and consistent kill of ticks by sarolaner within 24 h after a single oral dose over 28 days, suggests this treatment will provide highly effective and reliable control of ticks over the entire treatment interval, and could help reduce the risk of transmission of tick-borne pathogens by A. americanum.
    Full-text · Article · Dec 2016
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