The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
J. E. Lloyd - One of the best experts on this subject based on the ideXlab platform.
-
Persistent activity of moxidectin long-acting injectable formulations against natural and experimentally enhanced populations of lice infesting cattle.
Veterinary Parasitology, 2004Co-Authors: R. M. Cleale, J. E. Lloyd, R Kumar, Larry L. Smith, M.a Grubbs, Steven T. Grubbs, D. M. AmodieAbstract:A study was conducted under a common protocol in Wisconsin and Wyoming, USA, to evaluate therapeutic and persistent efficacy of two long-acting injectable formulations of moxidectin against lice populations infesting cattle. At each site, 30 beef calves were blocked into groups of three based on naturally acquired Linognathus vituli populations, then randomly assigned to treatments within blocks. Treatments, injected subcutaneously into the proximal third of the ear on Day 0, included saline, a long-acting oil-based formulation containing 10% moxidectin given at the rate of 1 mg moxidectin/kg body weight (M10/1.0), or a long-acting oil-based formulation containing 15% moxidectin given at the rate of 0.75 mg moxidectin/kg b.w. (M15/0.75). Species of sucking and chewing lice were quantified on nine predilection sites before treatment, then 28, 63, 98, 133 and 168 days after treatment. During intervals between lice counts after Day 28, study animals from the three treatment groups were commingled for 32 days with two lice-free sentinels plus four to six seeder calves with infestations of both sucking and chewing lice. Following each 32-day commingling interval, seeder and sentinel animals were removed, and principal animals were sorted into pens by treatment. Lice were quantified on sentinel animals on the day of removal, and lice were quantified on principal study animals 3 days after removal of sentinel and seeders. Moxidectin was generally not efficacious against Bovicola bovis in the injectable formulations tested, whereas Haematopinus eurysternus infestations were inadequate to judge product effectiveness. Based on geometric means, both M15/0.75 and M10/1.0 provided statistically significant therapeutic efficacy against existing infestations of L. vituli and Solenopotes capillatus (100% efficacy on Day 28), and provided persistent protection against reinfestation with L. vituli and S. capillatus (efficacy >97%) for at least 133 days following treatment.
-
Persistent efficacy of doramectin topical solution against induced infestations of Bovicola bovis and Solenopotes capillatus.
Veterinary parasitology, 2001Co-Authors: J. E. Lloyd, T L Skogerboe, J. W. Waggoner, L L Smith, R Kumar, M.a Grubbs, E.e Norelius, A.c Brake, V.k ShostromAbstract:Abstract A study was conducted in two locations, Wyoming and Wisconsin, USA, to evaluate the persistent efficacy of doramectin topical solution at a dose rate of 500 μg/kg body weight against artificially induced infestations of Bovicola bovis and Solenopotes capillatus on cattle. At each location, lice-free beef calves were individually housed and randomly allocated to treatment. Both B. bovis and S. capillatus were transferred from untreated donor animals to doramectin-treated cattle at the end of 35, 63, 91 or 126 day post-treatment periods. Cattle treated with a saline pour-on served as the control. Based on the geometric means of lice counts 2 weeks following transfer, the persistent efficacy of a single treatment with doramectin topical solution against induced infestations of B. bovis was 100.0, 100.0, 99.5, and 100.0% at post-treatment days of 35, 63, 91, and 126, respectively. Persistent efficacy against induced infestations of S. capillatus , for the same intervals, were 100.0, 94.9, 86.3, and 74.9%.
-
Eprinomectin: a novel avermectin for control of lice in all classes of cattle.
Veterinary parasitology, 1997Co-Authors: J. E. Holste, J. E. Lloyd, L L Smith, J.a. Hair, J.l. Lancaster, W.k. Langholff, R.a. Barrick, J.s. EaglesonAbstract:Abstract Eight trials were conducted in the United States to determine the efficacy of eprinomectin applied topically against four common species of lice in cattle. In two dose titration trials, eprinomectin dosages of 125 to 750 mcg/kg body weight applied topically were compared to untreated controls. In dose confirmation studies, animals treated topically with eprinomectin applied at the rate of 500 mcg/kg were compared to vehicle-treated controls. Four species of lice were present in these trials: Linognathus vituli, Haematopinus eurysternus, Solenopotes capillatus , all sucking lice, and Damalinia (Bovicola) bovis , the cattle biting louse. Louse counts were made on six to nine predilection sites (the same number of sites in all animals in the same trial) prior to treatment. The same sites were counted again seven days after treatment and weakly thereafter until trial termination eight weeks after treatment. When no lice were found in the predilection sites, a modified whole body search was conducted. Each species of lice was present on at least six animals in each treatment group on at least one counting date in two or more trials. No lice were found on any animal treated topically with eprinomectin at a dosage of ≥ 500 mcg/kg after 14 days postreatment until termination of the trials eight weeks after treatment
-
DENSITY AND DISTRIBUTION OF CATTLE LICE (PHTHIRAPTERA:HAEMATOPINIDAE, LINOGNATHIDAE, TRICHODECTIDAE) ON SIX STEERS
Veterinary parasitology, 1997Co-Authors: D.w. Watson, J. E. Lloyd, R KumarAbstract:Abstract The density and distribution of four species of cattle louse, Bovicola bovis (L.), Haematopinus eurysternus (Nitzsch), Linognathus vituli (L.), and Solenopotes capillatus (Enderlein), were elucidated from the hides of six slaughtered steers. Adult and nymphal lice were first removed from one hide by hand and the location of each specimen mapped. The remaining lice were removed by a detergent wash, and KOH dissolution of hide and hair. Lice from the remaining five hides were removed using KOH dissolution of cattle hair and subsequent filtration of the effluent. Bovicola bovis was most abundant, followed by H. eurysternus, L. vituli and S. capillatus . Significant variation was observed in B. bovis, H. eurysternus and L. vituli population densities. Solenopotes capillatus population densities did not differ significantly. All species were contagiously distributed, i.e. ‘clumped’, suggesting species dependant predilection sites. Predilection sites were ranked according to louse density to facilitate the development of field sampling strategies. Additional biological data were gathered on sex and life stage ratios for each species.
-
doramectin systemic activity against cattle grubs hypoderma lineatum and h bovis diptera oestridae and cattle lice Bovicola bovis mallophaga trichodectidae linognathus vituli and solenopotes capillatus anoplura linognathidae and haematopinus euryster
Veterinary Parasitology, 1996Co-Authors: J. E. Lloyd, J. W. Waggoner, R Kumar, F.e. PhillipsAbstract:Abstract Seven individual trials were conducted in Wyoming to evaluate the therapeutic efficacy of doramectin administered subcutaneously at a dosage of 200 μg kg−1 against multiple, natural infestations of cattle grubs or cattle lice. Insect species present and the number of trials that included each species were: Hypoderma lineatum, 2; Hypoderma bovis, 1; Bovicola bovis, 5; Haematopinus eurysternus, 1; Linognathus vituli, 5; and Solenopotes capillatus, 3. Examinations for lice were performed prior to treatment and either weekly or bi-weekly thereafter for 28 days. Examinations for cattle warbles were performed either weekly or every 4 to 5 weeks from time of first appearance through last appearance in the backs of the cattle. No H. lineatum, H. bovis, H. eurysternus, L. vituli, or S. capillatus were found on doramectin-treated animals at any time following treatment. By 29 days following treatment, the number of B. bovis was reduced between 58 and 98%. Treatments applied later in the season, i.e. in March, were more efficacious against B. bovis than those applied in January or February.
Daniel E. Snyder - One of the best experts on this subject based on the ideXlab platform.
-
Therapeutic and persistent efficacy of spinosad applied as a pour-on or a topical spray against natural infestations of chewing and sucking lice on cattle.
Veterinary Parasitology, 2006Co-Authors: W. Hunter White, Larry L. Smith, Douglas E. Hutchens, Carl J. Jones, Lawrence D. Firkins, Allan Paul, Daniel E. SnyderAbstract:Abstract Studies were conducted in Wisconsin and Illinois, USA, to assess and compare the therapeutic and persistent efficacy of spinosad when applied as either a pour-on or topical spray and compared with cyfluthrin pour-on and coumaphos topical spray for controlling natural infestations of chewing (Bovicola bovis) and sucking (Linognathus vituli, Solenopotes capillatus and Haematopinus eurysternus) lice on cattle. Thirty-five animals at each trial site were blocked according to pre-treatment lice counts and randomly allocated to one of five treatment groups: single treatments of spinosad (25 g/L), diluted with water to 0.04% active ingredient and applied as a whole-body topical spray; spinosad (25 g/L) applied as a neat pour-on at 2 mg/kg body weight; Co-Ral® Emulsifiable Livestock Insecticide (5.8% coumaphos), diluted to 0.03% active ingredient and applied as a whole-body topical spray; CyLence® Pour-on Insecticide (1% cyfluthrin), applied as a neat pour-on at the manufacturer's recommended use rate for lice; and untreated control. Both spinosad treatments and cyfluthrin provided ≥96% control of B. bovis for up to 7 weeks, whereas the efficacy of coumaphos dropped to
-
Therapeutic and persistent efficacy of spinosad applied as a pour-on or a topical spray against natural infestations of chewing and sucking lice on cattle.
Veterinary parasitology, 2006Co-Authors: W. Hunter White, Larry L. Smith, Douglas E. Hutchens, Lawrence D. Firkins, Carl Jones, Allan J Paul, Daniel E. SnyderAbstract:Studies were conducted in Wisconsin and Illinois, USA, to assess and compare the therapeutic and persistent efficacy of spinosad when applied as either a pour-on or topical spray and compared with cyfluthrin pour-on and coumaphos topical spray for controlling natural infestations of chewing (Bovicola bovis) and sucking (Linognathus vituli, Solenopotes capillatus and Haematopinus eurysternus) lice on cattle. Thirty-five animals at each trial site were blocked according to pre-treatment lice counts and randomly allocated to one of five treatment groups: single treatments of spinosad (25 g/L), diluted with water to 0.04% active ingredient and applied as a whole-body topical spray; spinosad (25 g/L) applied as a neat pour-on at 2 mg/kg body weight; Co-Ral Emulsifiable Livestock Insecticide (5.8% coumaphos), diluted to 0.03% active ingredient and applied as a whole-body topical spray; CyLence Pour-on Insecticide (1% cyfluthrin), applied as a neat pour-on at the manufacturer's recommended use rate for lice; and untreated control. Both spinosad treatments and cyfluthrin provided > or =96% control of B. bovis for up to 7 weeks, whereas the efficacy of coumaphos dropped to or =98% for at least 5 weeks at both sites, compared with 3 weeks for coumaphos at one site. Spinosad and coumaphos sprays provided 100% control of S. capillatus for at least 8 weeks compared with > or =97% control for spinosad and cyfluthrin pour-on treatments over the same interval. While H. eurysternus burden was low and limited to one study site, all four treatments provided 100% control for at least 6 weeks. These studies showed that topically applied spinosad provided a high degree of therapeutic and residual control against both sucking and chewing lice.
R Kumar - One of the best experts on this subject based on the ideXlab platform.
-
Persistent activity of moxidectin long-acting injectable formulations against natural and experimentally enhanced populations of lice infesting cattle.
Veterinary Parasitology, 2004Co-Authors: R. M. Cleale, J. E. Lloyd, R Kumar, Larry L. Smith, M.a Grubbs, Steven T. Grubbs, D. M. AmodieAbstract:A study was conducted under a common protocol in Wisconsin and Wyoming, USA, to evaluate therapeutic and persistent efficacy of two long-acting injectable formulations of moxidectin against lice populations infesting cattle. At each site, 30 beef calves were blocked into groups of three based on naturally acquired Linognathus vituli populations, then randomly assigned to treatments within blocks. Treatments, injected subcutaneously into the proximal third of the ear on Day 0, included saline, a long-acting oil-based formulation containing 10% moxidectin given at the rate of 1 mg moxidectin/kg body weight (M10/1.0), or a long-acting oil-based formulation containing 15% moxidectin given at the rate of 0.75 mg moxidectin/kg b.w. (M15/0.75). Species of sucking and chewing lice were quantified on nine predilection sites before treatment, then 28, 63, 98, 133 and 168 days after treatment. During intervals between lice counts after Day 28, study animals from the three treatment groups were commingled for 32 days with two lice-free sentinels plus four to six seeder calves with infestations of both sucking and chewing lice. Following each 32-day commingling interval, seeder and sentinel animals were removed, and principal animals were sorted into pens by treatment. Lice were quantified on sentinel animals on the day of removal, and lice were quantified on principal study animals 3 days after removal of sentinel and seeders. Moxidectin was generally not efficacious against Bovicola bovis in the injectable formulations tested, whereas Haematopinus eurysternus infestations were inadequate to judge product effectiveness. Based on geometric means, both M15/0.75 and M10/1.0 provided statistically significant therapeutic efficacy against existing infestations of L. vituli and Solenopotes capillatus (100% efficacy on Day 28), and provided persistent protection against reinfestation with L. vituli and S. capillatus (efficacy >97%) for at least 133 days following treatment.
-
Persistent efficacy of doramectin topical solution against induced infestations of Bovicola bovis and Solenopotes capillatus.
Veterinary parasitology, 2001Co-Authors: J. E. Lloyd, T L Skogerboe, J. W. Waggoner, L L Smith, R Kumar, M.a Grubbs, E.e Norelius, A.c Brake, V.k ShostromAbstract:Abstract A study was conducted in two locations, Wyoming and Wisconsin, USA, to evaluate the persistent efficacy of doramectin topical solution at a dose rate of 500 μg/kg body weight against artificially induced infestations of Bovicola bovis and Solenopotes capillatus on cattle. At each location, lice-free beef calves were individually housed and randomly allocated to treatment. Both B. bovis and S. capillatus were transferred from untreated donor animals to doramectin-treated cattle at the end of 35, 63, 91 or 126 day post-treatment periods. Cattle treated with a saline pour-on served as the control. Based on the geometric means of lice counts 2 weeks following transfer, the persistent efficacy of a single treatment with doramectin topical solution against induced infestations of B. bovis was 100.0, 100.0, 99.5, and 100.0% at post-treatment days of 35, 63, 91, and 126, respectively. Persistent efficacy against induced infestations of S. capillatus , for the same intervals, were 100.0, 94.9, 86.3, and 74.9%.
-
DENSITY AND DISTRIBUTION OF CATTLE LICE (PHTHIRAPTERA:HAEMATOPINIDAE, LINOGNATHIDAE, TRICHODECTIDAE) ON SIX STEERS
Veterinary parasitology, 1997Co-Authors: D.w. Watson, J. E. Lloyd, R KumarAbstract:Abstract The density and distribution of four species of cattle louse, Bovicola bovis (L.), Haematopinus eurysternus (Nitzsch), Linognathus vituli (L.), and Solenopotes capillatus (Enderlein), were elucidated from the hides of six slaughtered steers. Adult and nymphal lice were first removed from one hide by hand and the location of each specimen mapped. The remaining lice were removed by a detergent wash, and KOH dissolution of hide and hair. Lice from the remaining five hides were removed using KOH dissolution of cattle hair and subsequent filtration of the effluent. Bovicola bovis was most abundant, followed by H. eurysternus, L. vituli and S. capillatus . Significant variation was observed in B. bovis, H. eurysternus and L. vituli population densities. Solenopotes capillatus population densities did not differ significantly. All species were contagiously distributed, i.e. ‘clumped’, suggesting species dependant predilection sites. Predilection sites were ranked according to louse density to facilitate the development of field sampling strategies. Additional biological data were gathered on sex and life stage ratios for each species.
-
doramectin systemic activity against cattle grubs hypoderma lineatum and h bovis diptera oestridae and cattle lice Bovicola bovis mallophaga trichodectidae linognathus vituli and solenopotes capillatus anoplura linognathidae and haematopinus euryster
Veterinary Parasitology, 1996Co-Authors: J. E. Lloyd, J. W. Waggoner, R Kumar, F.e. PhillipsAbstract:Abstract Seven individual trials were conducted in Wyoming to evaluate the therapeutic efficacy of doramectin administered subcutaneously at a dosage of 200 μg kg−1 against multiple, natural infestations of cattle grubs or cattle lice. Insect species present and the number of trials that included each species were: Hypoderma lineatum, 2; Hypoderma bovis, 1; Bovicola bovis, 5; Haematopinus eurysternus, 1; Linognathus vituli, 5; and Solenopotes capillatus, 3. Examinations for lice were performed prior to treatment and either weekly or bi-weekly thereafter for 28 days. Examinations for cattle warbles were performed either weekly or every 4 to 5 weeks from time of first appearance through last appearance in the backs of the cattle. No H. lineatum, H. bovis, H. eurysternus, L. vituli, or S. capillatus were found on doramectin-treated animals at any time following treatment. By 29 days following treatment, the number of B. bovis was reduced between 58 and 98%. Treatments applied later in the season, i.e. in March, were more efficacious against B. bovis than those applied in January or February.
Larry L. Smith - One of the best experts on this subject based on the ideXlab platform.
-
Therapeutic and persistent efficacy of spinosad applied as a pour-on or a topical spray against natural infestations of chewing and sucking lice on cattle.
Veterinary parasitology, 2006Co-Authors: W. Hunter White, Larry L. Smith, Douglas E. Hutchens, Lawrence D. Firkins, Carl Jones, Allan J Paul, Daniel E. SnyderAbstract:Studies were conducted in Wisconsin and Illinois, USA, to assess and compare the therapeutic and persistent efficacy of spinosad when applied as either a pour-on or topical spray and compared with cyfluthrin pour-on and coumaphos topical spray for controlling natural infestations of chewing (Bovicola bovis) and sucking (Linognathus vituli, Solenopotes capillatus and Haematopinus eurysternus) lice on cattle. Thirty-five animals at each trial site were blocked according to pre-treatment lice counts and randomly allocated to one of five treatment groups: single treatments of spinosad (25 g/L), diluted with water to 0.04% active ingredient and applied as a whole-body topical spray; spinosad (25 g/L) applied as a neat pour-on at 2 mg/kg body weight; Co-Ral Emulsifiable Livestock Insecticide (5.8% coumaphos), diluted to 0.03% active ingredient and applied as a whole-body topical spray; CyLence Pour-on Insecticide (1% cyfluthrin), applied as a neat pour-on at the manufacturer's recommended use rate for lice; and untreated control. Both spinosad treatments and cyfluthrin provided > or =96% control of B. bovis for up to 7 weeks, whereas the efficacy of coumaphos dropped to or =98% for at least 5 weeks at both sites, compared with 3 weeks for coumaphos at one site. Spinosad and coumaphos sprays provided 100% control of S. capillatus for at least 8 weeks compared with > or =97% control for spinosad and cyfluthrin pour-on treatments over the same interval. While H. eurysternus burden was low and limited to one study site, all four treatments provided 100% control for at least 6 weeks. These studies showed that topically applied spinosad provided a high degree of therapeutic and residual control against both sucking and chewing lice.
-
Therapeutic and persistent efficacy of spinosad applied as a pour-on or a topical spray against natural infestations of chewing and sucking lice on cattle.
Veterinary Parasitology, 2006Co-Authors: W. Hunter White, Larry L. Smith, Douglas E. Hutchens, Carl J. Jones, Lawrence D. Firkins, Allan Paul, Daniel E. SnyderAbstract:Abstract Studies were conducted in Wisconsin and Illinois, USA, to assess and compare the therapeutic and persistent efficacy of spinosad when applied as either a pour-on or topical spray and compared with cyfluthrin pour-on and coumaphos topical spray for controlling natural infestations of chewing (Bovicola bovis) and sucking (Linognathus vituli, Solenopotes capillatus and Haematopinus eurysternus) lice on cattle. Thirty-five animals at each trial site were blocked according to pre-treatment lice counts and randomly allocated to one of five treatment groups: single treatments of spinosad (25 g/L), diluted with water to 0.04% active ingredient and applied as a whole-body topical spray; spinosad (25 g/L) applied as a neat pour-on at 2 mg/kg body weight; Co-Ral® Emulsifiable Livestock Insecticide (5.8% coumaphos), diluted to 0.03% active ingredient and applied as a whole-body topical spray; CyLence® Pour-on Insecticide (1% cyfluthrin), applied as a neat pour-on at the manufacturer's recommended use rate for lice; and untreated control. Both spinosad treatments and cyfluthrin provided ≥96% control of B. bovis for up to 7 weeks, whereas the efficacy of coumaphos dropped to
-
Persistent activity of moxidectin long-acting injectable formulations against natural and experimentally enhanced populations of lice infesting cattle.
Veterinary Parasitology, 2004Co-Authors: R. M. Cleale, J. E. Lloyd, R Kumar, Larry L. Smith, M.a Grubbs, Steven T. Grubbs, D. M. AmodieAbstract:A study was conducted under a common protocol in Wisconsin and Wyoming, USA, to evaluate therapeutic and persistent efficacy of two long-acting injectable formulations of moxidectin against lice populations infesting cattle. At each site, 30 beef calves were blocked into groups of three based on naturally acquired Linognathus vituli populations, then randomly assigned to treatments within blocks. Treatments, injected subcutaneously into the proximal third of the ear on Day 0, included saline, a long-acting oil-based formulation containing 10% moxidectin given at the rate of 1 mg moxidectin/kg body weight (M10/1.0), or a long-acting oil-based formulation containing 15% moxidectin given at the rate of 0.75 mg moxidectin/kg b.w. (M15/0.75). Species of sucking and chewing lice were quantified on nine predilection sites before treatment, then 28, 63, 98, 133 and 168 days after treatment. During intervals between lice counts after Day 28, study animals from the three treatment groups were commingled for 32 days with two lice-free sentinels plus four to six seeder calves with infestations of both sucking and chewing lice. Following each 32-day commingling interval, seeder and sentinel animals were removed, and principal animals were sorted into pens by treatment. Lice were quantified on sentinel animals on the day of removal, and lice were quantified on principal study animals 3 days after removal of sentinel and seeders. Moxidectin was generally not efficacious against Bovicola bovis in the injectable formulations tested, whereas Haematopinus eurysternus infestations were inadequate to judge product effectiveness. Based on geometric means, both M15/0.75 and M10/1.0 provided statistically significant therapeutic efficacy against existing infestations of L. vituli and Solenopotes capillatus (100% efficacy on Day 28), and provided persistent protection against reinfestation with L. vituli and S. capillatus (efficacy >97%) for at least 133 days following treatment.
W. Hunter White - One of the best experts on this subject based on the ideXlab platform.
-
Therapeutic and persistent efficacy of spinosad applied as a pour-on or a topical spray against natural infestations of chewing and sucking lice on cattle.
Veterinary Parasitology, 2006Co-Authors: W. Hunter White, Larry L. Smith, Douglas E. Hutchens, Carl J. Jones, Lawrence D. Firkins, Allan Paul, Daniel E. SnyderAbstract:Abstract Studies were conducted in Wisconsin and Illinois, USA, to assess and compare the therapeutic and persistent efficacy of spinosad when applied as either a pour-on or topical spray and compared with cyfluthrin pour-on and coumaphos topical spray for controlling natural infestations of chewing (Bovicola bovis) and sucking (Linognathus vituli, Solenopotes capillatus and Haematopinus eurysternus) lice on cattle. Thirty-five animals at each trial site were blocked according to pre-treatment lice counts and randomly allocated to one of five treatment groups: single treatments of spinosad (25 g/L), diluted with water to 0.04% active ingredient and applied as a whole-body topical spray; spinosad (25 g/L) applied as a neat pour-on at 2 mg/kg body weight; Co-Ral® Emulsifiable Livestock Insecticide (5.8% coumaphos), diluted to 0.03% active ingredient and applied as a whole-body topical spray; CyLence® Pour-on Insecticide (1% cyfluthrin), applied as a neat pour-on at the manufacturer's recommended use rate for lice; and untreated control. Both spinosad treatments and cyfluthrin provided ≥96% control of B. bovis for up to 7 weeks, whereas the efficacy of coumaphos dropped to
-
Therapeutic and persistent efficacy of spinosad applied as a pour-on or a topical spray against natural infestations of chewing and sucking lice on cattle.
Veterinary parasitology, 2006Co-Authors: W. Hunter White, Larry L. Smith, Douglas E. Hutchens, Lawrence D. Firkins, Carl Jones, Allan J Paul, Daniel E. SnyderAbstract:Studies were conducted in Wisconsin and Illinois, USA, to assess and compare the therapeutic and persistent efficacy of spinosad when applied as either a pour-on or topical spray and compared with cyfluthrin pour-on and coumaphos topical spray for controlling natural infestations of chewing (Bovicola bovis) and sucking (Linognathus vituli, Solenopotes capillatus and Haematopinus eurysternus) lice on cattle. Thirty-five animals at each trial site were blocked according to pre-treatment lice counts and randomly allocated to one of five treatment groups: single treatments of spinosad (25 g/L), diluted with water to 0.04% active ingredient and applied as a whole-body topical spray; spinosad (25 g/L) applied as a neat pour-on at 2 mg/kg body weight; Co-Ral Emulsifiable Livestock Insecticide (5.8% coumaphos), diluted to 0.03% active ingredient and applied as a whole-body topical spray; CyLence Pour-on Insecticide (1% cyfluthrin), applied as a neat pour-on at the manufacturer's recommended use rate for lice; and untreated control. Both spinosad treatments and cyfluthrin provided > or =96% control of B. bovis for up to 7 weeks, whereas the efficacy of coumaphos dropped to or =98% for at least 5 weeks at both sites, compared with 3 weeks for coumaphos at one site. Spinosad and coumaphos sprays provided 100% control of S. capillatus for at least 8 weeks compared with > or =97% control for spinosad and cyfluthrin pour-on treatments over the same interval. While H. eurysternus burden was low and limited to one study site, all four treatments provided 100% control for at least 6 weeks. These studies showed that topically applied spinosad provided a high degree of therapeutic and residual control against both sucking and chewing lice.