Control of fleas on pets and in homes by use of imidacloprid or lufenuron and a pyrethrin spray.

OBJECTIVE: To evaluate imidacloprid and the combination of lufenuron and pyrethrin to control flea infestations in households with pets. ANIMALS: 37 dogs and 19 cats in 34 flea-infested households. PROCEDURE: Households were assigned randomly to 1 of 2 groups. Pets in group 1 were treated topically with imidacloprid on day 0, then once a month for 90 days. Pets in group 2 were given lufenuron orally on day 0 and at monthly intervals for 90 days and also were treated topically with a pyrethrin spray every 1 to 2 weeks throughout the study. Flea numbers in homes were assessed by use of intermittent light traps, and flea burdens on pets were assessed using visual area counts done once a week during the first month, then every other week. RESULTS: One application of imidacloprid reduced flea burdens on pets by 96 and 93.5% on days 7 and 28, respectively, compared with day-0 burdens. Following 3 applications, flea burdens on pets and in homes were reduced by 98.8 and 99.9%, respectively. Lufenuron and pyrethrin spray reduced flea numbers on pets by 48.9 and 91.1% on days 7 and 28, respectively. By the end of the study, this combination reduced flea burdens on pets and in homes by 99.2 and 99.7%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Imidacloprid applied topically or lufenuron administered orally along with a topically applied pyrethrin spray were effective in eliminating fleas on pets and in homes. Flea control can be achieved with topical application of adulticides or oral administration of insect growth regulators without concomitant treatment of the surroundings.     

The simulation of growth rate in grazing sheep—A comparison of the NRC and ARC feeding standards

Models, based on the source data and assumptions of the NRC (1975) and ARC (1965)/MAFF (1975) feeding standards for sheep, are described. In comparison with observed liveweight changes in grazing sheep, both models were generally able to identify situations in which gain occurred, but overestimated rates of gain. Both systems appear to underestimate the maintenance energy requirement of grazing sheep.     

Biology and control of ticks infesting dogs and cats in North America

At least 15 different infectious agents and diseases are transmitted or produced by ticks parasitizing dogs and cats in North America. Those infectious agents and diseases are distributed among eight different tick species that commonly infest dogs and cats. All but one of these species are hard ticks with a three-host development cycle in which each motile stage (larva, nymph, and adult) feeds on a different host after molting. Tick species, disease occurrence, and peak activity of each tick life stage can vary dramatically depending on geographic and climatic conditions. Gaining an understanding of tick distribution, tick ecology, and seasonal occurrence of different tick life stages can help with the management of tick infestations and reduce the incidence of tick-transmitted diseases in dogs and cats. Control should be based on an understanding and management of ecologic factors responsible for tick infestations and selection of appropriate acaricides. Occasionally, topical acaricides will appear not to have prevented tick infestations. This lack of control may be real or perceived based on reinfestation rates and/or pet owner expectations of product performance.     

Efficacy of Fipronil (9.8% w/w) + (S)-Methoprene (8.8% w/w) and Imidacloprid (8.8% w/w) + Permethrin (44% w/w) against Dermacentor variabilis (American Dog Tick) on Dogs.

This study evaluated overall efficacy, percentage of dogs free of live ticks, retention of ticks, and efficacy against retained ticks of fipronil (9.8% w/w) + (S)-methoprene (8.8% w/w) and imidacloprid (8.8% w/w) + permethrin (44% w/w) spot-on topical solutions against Dermacentor variabilis infesting dogs. Fipronil + (S)-methoprene provided significantly (P less than .05) greater tick control compared with the control dogs for the entire 30-day study period. Conversely, the combination product of imidacloprid + permethrin demonstrated activity significantly (P less than .05) different from control dogs only up to day 23. Significantly (P less than .05) more dogs treated with fipronil + (S)-methoprene were free of live ticks compared with controls on days 3, 9, and 16. There was never a significant difference (P greater than .05) between control and imidacloprid + permethrin-treated dogs in numbers of dogs free of live ticks. After the initial 10-minute tick exposure, lower numbers of ticks were retained on the imidacloprid + permethrin-treated dogs than on the fipronil + (S)-methoprene-treated dogs. However, when evaluating the effectiveness of the acaricides on "retained ticks," it appears that while some of the ticks were rapidly knocked down on the imidacloprid + permethrin-treated dogs, efficacy against ticks still retained at 10 minutes was never greater than 50%.     

Efficacy of a topically applied spot-on formulation of a novel insecticide, metaflumizone, applied to cats against a flea strain (KS1) with documented reduced susceptibility to various insecticides

A spot-on metaflumizone formulation was evaluated in adult domestic short hair cats to determine its adultidical efficacy against a flea strain that has reduced susceptibility to a number of insecticides. Eight cats served as non-treated controls, eight cats were treated with a metaflumizone formulation at 0.2 ml/kg (40 mg metaflumizone/kg) and eight cats were treated with fipronil 10% w/v-(s)-methoprene 12%w/v at 0.075 ml/kg (7.5-7.7 mg fipronil/kg:9.0-9.2 mg (s)-methoprene/kg). On days -1, 7, 14, 21, 28, 35, and 42 each cat was infested with approximately 100 unfed KS1 cat fleas, Ctenocephalides felis. At approximately 48 h after treatment or infestation, each cat was combed to remove and count live fleas. Treatment with metaflumizone provided > or = 99.3% efficacy for 3 weeks post-treatment and then 97.4, 91.4 and 86.2% efficacy at 4, 5 and 6 weeks post-treatment, respectively. Fipronil-(s)-methoprene provided 99.6% efficacy at 1 week post-treatment and then 97.6, 96.4, 71.3, 22.0 and 13.1% efficacy at weeks 2, 3, 4, 5 and 6, respectively. The reductions in flea numbers were significantly greater for the metaflumizone treatment than for fipronil-(s)-methoprene from 3 to 6 weeks after treatment.     

Evaluation of an imidacloprid (8.8% w/w)--permethrin (44.0% w/w) topical spot-on and a fipronil (9.8% w/w)--(S)-methoprene (8.8% w/w) topical spot-on to repel, prevent attachment, and kill adult Ixodes scapularis and Amblyomma americanum ticks on dogs

This study evaluated the effectiveness of two topical spot-on formulations -- imidacloprid(8.8% w/w)-permethrin (44.0% w/w) and fipronil (9.8% w/w)-(S)-methoprene (8.8% w/w)--to repel, prevent the attachment of, and kill adult Ixodes scapularis and Amblyomma americanum on dogs. Twelve purpose-bred beagles were distributed into three groups of four dogs each; one group served as untreated controls, and each of the other two groups received one of the test products. Dogs were exposed to 25 adult ticks of each species for 10 minutes on posttreatment days 3, 7, 14, 21, and 28. Unattached or repelled ticks were collected and evaluated for viability, and on-dog tick counts were conducted at 3, 24, and 48 hours after tick exposure. The imidacloprid-permethrin formulation provided significant repellency against I. scapularis for up to 3 weeks after treatment, and both formulations provided good overall control of I. scapularis and A. americanum during the study period.