moxidectin and Lice-Infestations

To evaluate the persistent activity of pour-on and injectable moxidectin against natural challenge by sucking (predominantly Linognathus vituli) and chewing (Bovicola bovis) cattle lice, 96 mixed-breed calves that had been treated to remove all lice were blocked by body weight and randomly allocated to three treatments: untreated control, moxidectin at 500 microg/kg by topical application and moxidectin at 200 microg/kg by subcutaneous injection. Twelve pens were blocked into groups of four and randomly allocated to four challenge times: 14, 21, 28 and 35 days post-treatment. Treatment groups were assigned to challenge pens randomly. Two donor calves, with demonstrated infestations of both sucking and chewing lice, were introduced into each pen containing eight principal calves at the start of each challenge time. Donors remained in the challenge pen for 7 days. Principal calves were examined for lice, 7, 14, 21 and 28 days after donor removal using a standardized hair-parting technique. Moxidectin injectable prevented re-infestation with L. vituli for up to 42 days, but did not provide persistent activity against B. bovis longer than 35 days post-treatment. Moxidectin pour-on demonstrated persistent activity against both B. bovis and L. vituli for 42 days.

Topics: Administration, Topical; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Female; Injections, Subcutaneous; Insecticides; Lice Infestations; Macrolides; Male; Phthiraptera

Topics: Administration, Topical; Animals; Anti-Bacterial Agents; Canada; Cattle; Cattle Diseases; Insecticides; Ivermectin; Lice Infestations; Macrolides; Male; Seasons

Field efficacy of a pour-on formulation of moxidectin, a macrocyclic lactone endectocide, was evaluated in cattle naturally infested with Chorioptes bovis, Damalinia bovis, Linognathus vituli and Psoroptes ovis. In trial 1, two experimental groups of cattle naturally infested with P. ovis were formed. Group 1 animals remained as untreated controls whereas Group 2 animals were treated on day 0 with 0.5% moxidectin cattle pour-on at a dose of 0.5 mg kg-1 bw. Efficacy was assessed by (a) taking skin samples from each animal on days -4, 7, 14, 21, 28, 42 and 56 post treatment (PT) and observing the numbers of viable P. ovis mites and (b) clinical examination of animals on days 7, 14, 21, 28, 42 and 56 with the percentage of affected body surface calculated and live body weights recorded for each animal on days 4, 28 and 42. The pour-on formulation of moxidectin yielded excellent efficacy as no live mites were found in treated animals at 14, 21, 28, 42 and 56 days PT, except in one animal from which one adult mite was collected on day 42. Clinical indices showed a regular decrease in the affected body surface area. All untreated animals but one remained positive until day 28 and their clinical condition worsened rapidly. In trial 2, two experimental groups of cattle naturally infested with D. bovis and L. vituli were selected. Group 1 remained as untreated controls whereas Group 2 individuals were treated on day 0 with 0.5% moxidectin cattle pour-on at a dose of 0.5 mg kg-1 bw. Efficacy was assessed by identifying and counting lice on eight 15 cm hair partings at predefined anatomical sites on days 0, 14, 28 and 42. On the basis of animals cured and lice count reduction, efficacies were 100% on day 14 and from then onwards for both species. In trial 3, 24 animals naturally infested with C. bovis were divided into three experimental groups comprising eight (Group I), seven (Group 2) and nine animals (Group 3). Group 1 was the untreated control group whereas Groups 2 and 3 animals were treated on day 0 with 0.5% moxidectin cattle pour-on at a dose of 0.25 mg and 0.5 mg kg-1 bw, respectively. Efficacy was assessed as in trial 1. Skin scrapings were collected on days -3, 7, 14, 28, 42 and 56 PT. A clinical index was calculated for each animal on days 0, 28 and 56 whereas body weights were recorded on days 0 and 56. At 0.25 mg kg-1 bw, the efficacy of moxidectin cattle pour-on against C. bovis was incomplete. In contrast, at a dose of 0.5 mg kg-1 bw, moxidectin cat

Topics: Administration, Topical; Animals; Anti-Bacterial Agents; Belgium; Cattle; Cattle Diseases; Female; Insecticides; Lice Infestations; Macrolides; Mite Infestations; Skin; Statistics, Nonparametric

Guinea pigs are susceptible to lice infestations. Ten guinea pigs infested with Gliricola porcelli were free of adult lice and eggs, and of adverse reactions, 30 days after treatment, with a single application of 0.05 mL of a solution containing 10% (w/v) imidacloprid and 1% (w/v) moxidectin indicating that this procedure is an effective treatment for lice infestations in guinea pigs.

Topics: Animals; Female; Guinea Pigs; Imidazoles; Insecticides; Lice Infestations; Macrolides; Male; Neonicotinoids; Nitro Compounds; Rodent Diseases; Treatment Outcome

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.

Topics: Animals; Cattle; Cattle Diseases; Female; Injections, Subcutaneous; Insecticides; Least-Squares Analysis; Lice Infestations; Macrolides; Male; Phthiraptera; Random Allocation

Topics: Administration, Topical; Animals; Anoplura; Anti-Bacterial Agents; Cattle; Cattle Diseases; Insecticides; Ivermectin; Lice Infestations; Macrolides; Male; Phthiraptera

The efficacy of one administration of moxidectin against natural infestations of the 3 common species of cattle lice in Australia: Linognathus vituli, Damalinia bovis and Haematopinus eurysternus, was determined. A high degree of control of L vituli (the long-nosed sucking louse) was achieved with both the cattle injection (96.7% and 100%) at 0.2 mg/kg and the cattle pour-on formulation (94.6% and 100%) at 0.5 mg/kg on the 2 farms where this louse occurred. An injection of moxidectin at 0.2 mg/kg did not eliminate D bovis. In these trials efficacy ranged from nil to 85.2%. In contrast the pour-on formulation at 0.5 mg/kg provided consistently high efficacy (83.6 to 100%) against D bovis on 3 farms. Infestations of H eurysternus (the short-nosed sucking louse) were low and no significant difference was recorded between treatment groups in a single trial, however, lice persisted on 3 to 7 cattle in the untreated group at each inspection, whereas none were found on any animals in the 2 groups treated with moxidectin on inspection after treatment.

Topics: Administration, Topical; Animals; Anoplura; Anti-Bacterial Agents; Cattle; Cattle Diseases; Female; Injections, Subcutaneous; Insecticides; Lice Infestations; Macrolides; Male; Phthiraptera

Slow release formulations of 375, 750, and 1,125 mg (AI) in 50-g boluses and a subcutaneous injectable formulation (0.2 mg AI/kg body wt) of moxidectin (CL301423) were tested for the control of the little blue cattle louse, Solenoptes capillatus (Enderlein), and the cattle biting louse, Bovicola bovis (L). S. capillatus populations were reduced 4 wk after treatment and complete control was observed 6 wk after treatment in groups treated with boluses, B. bovis were first observed at 3 wk and continued to increase throughout the 14-wk test period. These were experimental boluses and future boluses may perform differently. Subcutaneous injections of moxidectin gave complete control of S. capillatus for a 27-d test period. Feces from animals treated with boluses were tested with face fly larvae, Musca autumnalis De Geer, to demonstrate fecal activity of moxidectin. Larval mortality in these groups ranged from 90 to 30% from 2 d to 10 wk after treatment.

Topics: Animals; Anoplura; Anthelmintics; Anti-Bacterial Agents; Cattle; Cattle Diseases; Ectoparasitic Infestations; Female; Lice Infestations; Macrolides; Male; Muscidae; Phthiraptera