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R A Muniz - One of the best experts on this subject based on the ideXlab platform.
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protective efficacy of Doramectin and ivermectin against cochliomyia hominivorax
Veterinary Parasitology, 1997Co-Authors: G E Moyaborja, R A Muniz, O Umehara, L C B Goncalves, D S F Silva, M E MckenzieAbstract:Abstract Two studies were conducted in Brazil using induced infestations of the New World screwworm, Cochliomyia hominivorax , to investigate: a) the comparative prophylactic efficacy of Doramectin and ivermectin at their recommended use levels (200 μg kg −1 SC), and b) the duration of protection of a single injection of Doramectin. In the comparative efficacy study, two groups of six animals each were treated with ivermectin or Doramectin. Two hours after treatment, four incisions were made. Each incision was infested with 30 first instar C. hominivorax larvae and their status evaluated daily for 7 days post-treatment (p.t.) Doramectin treatment was 100% effective in prevention of C. hominivorax infestations whereas ivermectin efficacy was incomplete. First instar larvae were eliminated in Doramectin-treatmd calves by 48 h p.t., while in the ivermectin group, C. hominivorax developed in over 29% of the incisions. Healing began in wounds of Doramectin-treated animals at 24 h p.t. and was in progress in 100% of all wounds at 2 days p.t., while 50% of ivermectin-treated calves showed incisions with active lesions. In the duration of protection study, 24 calves were allocated to six groups (T1–T6) of four animals each. Three groups (T1, T3 and T5) were treated with saline and three groups (T2, T4 and T6) with Doramectin. Animals were infested as described previously according to the following schedule: T1 and T2 at day 14, T3 and T4 at day 21, and T5 and T6 at day 28 p.t. Incisions were evaluated daily for 8 days post-infestation. Screwworm infestations and viable third-instar larvae developed of all incisions of saline-treated calves, while Doramectin was 100% effective preventing development of C. hominivorax for 21 days p.t. and showed partial activity at 28 days p.t.
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Efficacy of injectable Doramectin in the therapy and control of Dermatobia hominis infestations in Latin America.
Veterinary Parasitology, 1995Co-Authors: R A Muniz, O Umehara, J Moreno, Alfredo Coronado, R. Cerqueira-leite, O. Soraci, J ErrecaldeAbstract:Three studies were conducted in Latin America, one in Brazil, one in Venezuela and one in Argentina, using a common protocol to investigate the efficacy of a single subcutaneous injection of Doramectin at 200 μg kg−1 (1 ml per 50 kg) for the treatment and control of Dermatobia hominis infestations in cattle raised under commercial conditions. In each study, two groups of 20 animals each were allocated on the basis of D. hominis nodules present 24 h before treatment to a treated group (T1), or to a control group (T2) which received saline solution at 1 ml per 50 kg of live weight. All cattle were injected in the mid-dorsal cervical region and examined on treatment day and 2, 7, 15 and 30 days post-treatment (p.t.). At each observation day the number of D. hominis nodules was counted and the viability of the larvae inside them was assessed and recorded. Treatment with Doramectin was 100% effective in eliminating D. hominis larvae and in controlling the re-establishment of the parasite under field conditions of continuous reinfestation. During the first 48 h p.t., dead larvae of different ages were found outside or partially outside the nodules in animals of the Doramectin groups. After 48 h p.t., no live larvae were found inside existing nodules, nor did new nodules develop in animals of the Doramectin groups in any of the three studies. When compared with nodule counts in the control group on the same observation day or with parasite burdens on the same animal before treatment, Doramectin-treated animals began to eliminate parasitic nodules at 48 h p.t. Efficacy reached 100% at 7 days p.t. and remained at 100% on subsequent observation days (P
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efficacy of injectable Doramectin in the protection of castrated cattle against field infestations of cochliomyia hominivorax
Veterinary Parasitology, 1995Co-Authors: R A Muniz, O S Anziani, J Errecalde, J Moreno, A Sanavria, Alfredo Coronado, L C B GoncalvesAbstract:Abstract Three studies were conducted in Latin America—one in Venezuela, one in Argentina and one in Brazil—using a common protocol to investigate the efficacy of a single subcutaneous injection of Doramectin in the prevention and control of Cochliomyia hominivorax infestations in castrated cattle. In each study, two groups of 20–28 animals each were allocated to a treated (TI) or to a control (T2) group on the basis of body weights. Animals of TI received Doramectin at 200 μg kg−1 (1 ml per 50 kg) and animals of 72 received saline solution at 1 ml per 50 kg of live weight. After treatment all cattle were castrated surgically. Animals were examined on treatment day and at 2, 4, 6 and 12 days post-treatment. At each observation day, the presence of C. hominivorax infestations was recorded. Doramectin was 100% effective in the prevention and control of screwworm strikes in castrated cattle exposed to continuous field infestations of C. hominivorax in tropical and subtropical areas of Latin America. Over the 12 day duration of the studies, 85%, 60% and 65% of animals in the control groups had infested wounds in Venezuela, Argentina and Brazil, respectively. Affected animals required repeated therapeutic treatment, whereas none of the Doramectin-treated cattle were infested (P
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efficacy of Doramectin in the protection of neonatal calves and post parturient cows against field strikes of cochliomyia hominivorax
Veterinary Parasitology, 1995Co-Authors: R A Muniz, O S Anziani, J Ordonez, J Errecalde, J MorenoAbstract:Abstract Two studies were conducted in Latin America, one in Venezuela and one in Argentina, using a common protocol to investigate the efficacy of a single s.c. injection of Doramectin in the prevention and control of field infestations of Cochliomyia hominivorax in newborn calves and post-parturient cows. In both experiments, pregnant cows were paired on the basis of their calving time. The first cow that calved was assigned to a medicated group, and both cow and calf were treated with Doramectin. The cow received a dose of 200 μg kg−1 and the calf 1 ml of a 1% Doramectin solution. The second cow and calf were assigned to a saline-treated group, and the cow received saline at 1 ml per 50 kg and the calf 1 ml. The procedure was repeated until all animals were allocated to the two treatments. Animals were examined on the treatment day and at 2, 4, 6 and 12 days post-treatment. At each observation day, the navel of newborn calves and external genitalia of the cows were inspected and the presence of C. hominivorax infestations was recorded. Doramectin was 100% effective in the prevention and control of screwworm strikes in newborn calves and in post-parturient cows exposed to continuous field challenge of C. hominivorax. Over the 12 day duration of the studies, 48% and 57% of the saline-treated calves had screwworm navel strikes in the studies in Venezuela and Argentina, respectively. Infested animals required repeated therapeutic treatment, whereas none of the Doramectin-treated calves were affected (P
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EFFICACY OF INJECTABLE Doramectin AGAINST NATURAL BOOPHILUS MICROPLUS INFESTATIONS IN CATTLE
American Journal of Veterinary Research, 1995Co-Authors: R A Muniz, J Errecalde, J Moreno, F. Hernandez, O. Lombardero, R. C. Leite, L C B GoncalvesAbstract:Three experiments were conducted in Latin America--1 in Brazil, 1 in Venezuela, and 1 in Argentina--using a common protocol to investigate the efficacy of a single SC injection of Doramectin (200 micrograms/kg of body weight) for treatment and control of Boophilus microplus infestations in grazing cattle. In each experiment, 2 groups of 20 to 27 cattle were allocated on the basis of tick burdens present 24 hours before treatment to a treated or control group, which received saline solution (1 ml/50 kg). All cattle were injected in the mid-dorsal cervical region and examined on treatment day and on posttreatment days (PTD) 8, 14, 21, and 28. On each observation day, the number of engorged and semiengorged ticks on half of each animals was counted and recorded. Doramectin was highly efficacious in removing tick burdens and controlling reestablishment of B microplus under field conditions of continuous reinfestation. Compared with tick counts in the control group, Doramectin-treated cattle began to eliminate ticks after treatment and efficacy improved on subsequent observation days. In Brazil, efficacy was 91% at PTD 8 and 14, and increased to 99% or higher at PTD 21 and 28. In Venezuela, efficacy was 100% at PTD 8, 14, and 21 and 92% at PTD 28. In Argentina, efficacy progressed from 94.5% at PTD 8 to 99 and 98.5% at PTD 21 and 28, respectively. The reduction of the number of ticks in the Doramectin-treated cattle was significant (P < 0.05) at each observation day.(ABSTRACT TRUNCATED AT 250 WORDS)
L C B Goncalves - One of the best experts on this subject based on the ideXlab platform.
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protective efficacy of Doramectin and ivermectin against cochliomyia hominivorax
Veterinary Parasitology, 1997Co-Authors: G E Moyaborja, R A Muniz, O Umehara, L C B Goncalves, D S F Silva, M E MckenzieAbstract:Abstract Two studies were conducted in Brazil using induced infestations of the New World screwworm, Cochliomyia hominivorax , to investigate: a) the comparative prophylactic efficacy of Doramectin and ivermectin at their recommended use levels (200 μg kg −1 SC), and b) the duration of protection of a single injection of Doramectin. In the comparative efficacy study, two groups of six animals each were treated with ivermectin or Doramectin. Two hours after treatment, four incisions were made. Each incision was infested with 30 first instar C. hominivorax larvae and their status evaluated daily for 7 days post-treatment (p.t.) Doramectin treatment was 100% effective in prevention of C. hominivorax infestations whereas ivermectin efficacy was incomplete. First instar larvae were eliminated in Doramectin-treatmd calves by 48 h p.t., while in the ivermectin group, C. hominivorax developed in over 29% of the incisions. Healing began in wounds of Doramectin-treated animals at 24 h p.t. and was in progress in 100% of all wounds at 2 days p.t., while 50% of ivermectin-treated calves showed incisions with active lesions. In the duration of protection study, 24 calves were allocated to six groups (T1–T6) of four animals each. Three groups (T1, T3 and T5) were treated with saline and three groups (T2, T4 and T6) with Doramectin. Animals were infested as described previously according to the following schedule: T1 and T2 at day 14, T3 and T4 at day 21, and T5 and T6 at day 28 p.t. Incisions were evaluated daily for 8 days post-infestation. Screwworm infestations and viable third-instar larvae developed of all incisions of saline-treated calves, while Doramectin was 100% effective preventing development of C. hominivorax for 21 days p.t. and showed partial activity at 28 days p.t.
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efficacy of injectable Doramectin in the protection of castrated cattle against field infestations of cochliomyia hominivorax
Veterinary Parasitology, 1995Co-Authors: R A Muniz, O S Anziani, J Errecalde, J Moreno, A Sanavria, Alfredo Coronado, L C B GoncalvesAbstract:Abstract Three studies were conducted in Latin America—one in Venezuela, one in Argentina and one in Brazil—using a common protocol to investigate the efficacy of a single subcutaneous injection of Doramectin in the prevention and control of Cochliomyia hominivorax infestations in castrated cattle. In each study, two groups of 20–28 animals each were allocated to a treated (TI) or to a control (T2) group on the basis of body weights. Animals of TI received Doramectin at 200 μg kg−1 (1 ml per 50 kg) and animals of 72 received saline solution at 1 ml per 50 kg of live weight. After treatment all cattle were castrated surgically. Animals were examined on treatment day and at 2, 4, 6 and 12 days post-treatment. At each observation day, the presence of C. hominivorax infestations was recorded. Doramectin was 100% effective in the prevention and control of screwworm strikes in castrated cattle exposed to continuous field infestations of C. hominivorax in tropical and subtropical areas of Latin America. Over the 12 day duration of the studies, 85%, 60% and 65% of animals in the control groups had infested wounds in Venezuela, Argentina and Brazil, respectively. Affected animals required repeated therapeutic treatment, whereas none of the Doramectin-treated cattle were infested (P
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EFFICACY OF INJECTABLE Doramectin AGAINST NATURAL BOOPHILUS MICROPLUS INFESTATIONS IN CATTLE
American Journal of Veterinary Research, 1995Co-Authors: R A Muniz, J Errecalde, J Moreno, F. Hernandez, O. Lombardero, R. C. Leite, L C B GoncalvesAbstract:Three experiments were conducted in Latin America--1 in Brazil, 1 in Venezuela, and 1 in Argentina--using a common protocol to investigate the efficacy of a single SC injection of Doramectin (200 micrograms/kg of body weight) for treatment and control of Boophilus microplus infestations in grazing cattle. In each experiment, 2 groups of 20 to 27 cattle were allocated on the basis of tick burdens present 24 hours before treatment to a treated or control group, which received saline solution (1 ml/50 kg). All cattle were injected in the mid-dorsal cervical region and examined on treatment day and on posttreatment days (PTD) 8, 14, 21, and 28. On each observation day, the number of engorged and semiengorged ticks on half of each animals was counted and recorded. Doramectin was highly efficacious in removing tick burdens and controlling reestablishment of B microplus under field conditions of continuous reinfestation. Compared with tick counts in the control group, Doramectin-treated cattle began to eliminate ticks after treatment and efficacy improved on subsequent observation days. In Brazil, efficacy was 91% at PTD 8 and 14, and increased to 99% or higher at PTD 21 and 28. In Venezuela, efficacy was 100% at PTD 8, 14, and 21 and 92% at PTD 28. In Argentina, efficacy progressed from 94.5% at PTD 8 to 99 and 98.5% at PTD 21 and 28, respectively. The reduction of the number of ticks in the Doramectin-treated cattle was significant (P < 0.05) at each observation day.(ABSTRACT TRUNCATED AT 250 WORDS)
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therapeutic and persistent efficacy of Doramectin against boophilus microplus in cattle
Veterinary Parasitology, 1993Co-Authors: Joao Carlos Gonzales, R A Muniz, Alberto Queiroz Farias, L C B GoncalvesAbstract:Abstract One therapeutic and one persistent efficacy study were conducted in Brazil to evaluate Doramectin at a dose rate of 200 μg kg−1 against induced infestations of the single host tick, Boophilus microplus. Doramectin was highly effective in eliminating established tick populations from cattle and also in preventing infestation by the parasite. In the therapeutic study, 12 calves were infested three times a week along the dorsal line with 2500 recently hatched larvae, for a total of 11 times before treatment. Animals were allocated to two groups on the basis of uniformity of established engorged tick burdens. Six calves were treated with Doramectin and six received saline solution. From Day -3 to Day 21 post-treatment, individual collections of detached engorged female ticks were made from each calf. In the persistent efficacy study, 12 calves were allocated to two groups of six animals. Six calves were treated with Doramectin and six received saline solution. From Day 1 to Day 17 post-treatment, each animal was infested three times a week along the dorsal line with 2500 recently hatched Boophilus microplus larvae, for a total of nine times. From Day 18 to Day 42 post-treatment, daily collections of detached engorged female ticks were made from individual animals. In the therapeutic study, efficacy (reduction of collected engorged female ticks) progressed from 51% at 24 h post-treatment (p.t.) to at least 99% at 4 days p.t., and reached 100% at 8 days p.t. With the exception of one tick that did not lay eggs, recovered from one animal at 11 days p.t., no more ticks were recovered from Doramectin-treated calves for the duration of the experiment. For the first 6 days after treatment, only a few detached engorged ticks were collected from treated animals, and their oviposition and hatchability declined rapidly. In the persistent efficacy study, Doramectin treatment was highly efficacious in preventing the establishment of Boophilus microplus populations for 20 days after the first ticks completed their cycle in the non-treated group. The oviposition and hatchability of the few ticks that completed their life cycle in the Doramectin group were severely reduced.
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prophylactic and persistent efficacy of Doramectin against cochliomyia hominivorax in cattle
Veterinary Parasitology, 1993Co-Authors: G E Moyaborja, R A Muniz, C M B Oliveira, L C B GoncalvesAbstract:Abstract Two prophylactic studies and one persistent efficacy study were conducted in Brazil to evaluate one injection of Doramectin at a dose rate of 200 μg kg −1 against induced infestations of the New World screwworm, Cochliomyia hominivorax . In each prophylactic study, 12 calves were allocated to two groups of six animals. Six calves were treated with Doramectin and six with saline. Two hours after treatment, animals were anesthetized and received two incisions, one in the shoulder and one in the rump. Each incision was then infested with 50 first instar larvae. In the persistent efficacy study, 24 calves were allocated to six groups (T1–T6) of four animals each. On the day of treatment, three groups (T1, T3 and T5) were treated with saline and three groups (T2, T4 and T6) with Doramectin. All animals were anesthetized and received four incisions, one in the shoulder and one in the rump of each side. Each incision was then infested with 30 first instar larvae of C. hominivorax with the following schedule: T1 and T2 at Day 3, T3 and T4 at Day 7, and T5 and T6 at Day 14 post-treatment. Calves were observed daily and incisions evaluated for 8 days post-infection. Larvae that completed development and exited the wounds were collected and incubated to evaluate viability. In all experiments, Doramectin was 100% efficacious in preventing screwworm infestation caused by field isolates of C. hominivorax . First instar larvae were eliminated from the incisions of Doramectin-treated calves between 24 and 48 h post-treatment, and no third instar were recovered at any time. As a consequence, healing started at 24 h and was completed at 96–120 h post-infection. Screwworm infestations and viable third-instar larvae developed in all the incisions in non-treated calves, and healing did not begin until larvae had completed their normal life cycle and exited the wounds. The persistent efficacy of a single injection of Doramectin extended beyond 14 days.
A J Weatherley - One of the best experts on this subject based on the ideXlab platform.
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efficacy of a pour on formulation of Doramectin against lice mites and grubs of cattle
American Journal of Veterinary Research, 1999Co-Authors: K. A. Rooney, N B Logan, A J Weatherley, E. F. Illyes, D. S. Keller, T. R. Meinert, M O Hendrickx, S J Sunderland, P Sarasola, George A. ConderAbstract:OBJECTIVE: To determine effectiveness of a pour-on formulation of Doramectin against Damalinia bovis, Haematopinus eurysternus, Linognathus vituli, Solenopotes capillatus, Chorioptes bovis, Sarcoptes scabiei, Hypoderma bovis, and Hypoderma lineatum. ANIMALS: Cattle of various ages with naturally acquired or artificial infestations with 1 or more species of lice, mites, or grubs. PROCEDURE: In 10 louse and 6 mite studies, cattle were treated with Doramectin (500 microg/kg, topically) on day 0, and parasite counts were performed approximately weekly from days 0 to 35. In 6 grub studies, cattle expected to harbor Hypoderma spp were treated before emergence of warbles. After warbles began to emerge, they were counted every 2 weeks, and grubs were collected and identified by species. RESULTS: Burdens of D bovis, H eurystemus, L vituli, and S capillatus on Doramectin-treated cattle were 0 by 28 days after treatment. Burdens of C bovis and S scabiei decreased to 0 in naturally infested cattle and approximately 0 in artificially infested cattle by day 14 to 15. In grub studies, 107 of 136 control cattle had warbles, whereas 2 of 136 Doramectin-treated cattle had 1 warble each, which represented a cure rate of 98.5%. CONCLUSION AND CLINICAL RELEVANCE: One topical application of Doramectin was highly efficacious against common species of lice, mites, and grubs known to affect performance, health, and appearance of cattle.
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Activity of Doramectin against nematode and arthropod parasites of swine
Veterinary Parasitology, 1996Co-Authors: N B Logan, A J Weatherley, R M JonesAbstract:Abstract The efficacy of Doramectin, a novel avermectin, was assessed against both naturally-acquired and experimentally-induced infections of gastrointestinal roundworms, lungworms, kidneyworms, lice and mites in studies conducted across North America and Europe. Twenty-two studies evaluated efficacy against fourth larval and adult stages of the following nematode species: Hyostrongylus rubidus, Ascaris suum, Strongyloids ransomi, Oesophagostomum dentatum, Oesophagostomum quarispinulatum, Trichuris suis, Metastrongylus spp. and Stephanurus dentatus. Efficacy was evaluated against the louse Haematopinus suis in six studies and against the mite Sarcoptes scabiei in four studies. A common study design was employed for each study type. In all studies, animals were allotted at random to a Doramectin-treated or a saline-treated group. The Doramectin-treated group received the drug at 300 μg kg−1 by intramuscular injection while the saline-treated group received saline by the same route. In the nematode studies, worm burdens were determined for each animal at slaughter 14–16 days after treatment. Efficacy against each nematode species/stage was assessed on the basis of percentage reduction in geometric mean worm burden in Doramectin-treated animals compared with saline-treated controls. In louse and mite studies, counts were made immediately before treatment and then at weekly intervals for four weeks. Efficacy was based on a comparison of the level of infestation on the day of treatment with that on the last day of test. Data from individual studies were combined to derive a single estimate of efficacy against each of the parasite species represented in the study program. Efficacy of Doramectin was 98% or greater against all nematode species except T. suis for which the efficacy was 87% and 79% against adult and fourth larval stage, respectively. Efficacy was 100% against both Haematopinus suis and Sarcoptes scabiei.
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activity of Doramectin against nematode endoparasites of cattle
Veterinary Parasitology, 1993Co-Authors: R M Jones, N B Logan, A J Weatherley, A S Little, C D SmothersAbstract:Abstract A series of 28 controlled anthelmintic studies, involving 634 cattle, was conducted throughout North America and Europe to evaluate the efficacy of Doramectin against a broad range of gastrointestinal parasitic nematode species and lungworms in naturally and experimentally infected animals. Within each study, one or two groups were treated with Doramectin at 200 μg kg−1 and another group received no drug treatment. Worm burdens were estimated by standardised techniques, and efficacy assessed on reduction of worm burdens in Doramectin-treated animals. Doramectin was at least 99.6% effective (P
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efficacy of Doramectin against warble fly larvae hypoderma bovis
Veterinary Parasitology, 1993Co-Authors: M O Hendrickx, L Anderson, C Boulard, D G Smith, A J WeatherleyAbstract:Abstract The efficacy of Doramectin in the treatment of cattle harbouring naturally acquired infestations of first, second and third instar larvae of Hypoderma bovis was determined in two studies carried out in the Burgundy region of France. In the first study, cattle on six farms with a history of H. bovis infestations were treated during October 1989 with either Doramectin at a dose of 200 μg kg−1 liveweight (186 animals) or with an equivalent volume of saline (157 animals). During the following March and April, all animals were examined for the presence of warbles. In the second study, cattle on four farms with warbles present in their backs were treated during March 1990, with either Doramectin or saline (as before). The viability of larvae within each warble on all the animals was then assessed every 2 days for 14 days. In Study 1, no warbles were present in any of the Doramectin-treated cattle at any time, whereas warbles were found in 135 saline-treated animals. In Study 2, all larvae in warbles on the backs of the Doramectin-treated cattle were dead by Day 14 after treatment, whereas viable larvae were still present in warbles in the backs of all saline-treated cattle. No adverse reaction to Doramectin treatment was observed in any animal at any time. It was concluded that Doramectin is both safe and 100% efficacious in the treatment of first, second and third instar H. bovis infections of cattle.
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efficacy of Doramectin in the prevention of gastrointestinal nematode infections in grazing cattle
Veterinary Parasitology, 1993Co-Authors: Jozef Vercruysse, D G Smith, Pierre Dorny, C Hong, T J Harris, N C Hammet, A J WeatherleyAbstract:Abstract Two studies were performed to investigate the efficacy of Doramectin in the prevention of infection with Osteriagia ostertagi and Cooperia oncophora in grazing calves. In each study, 24 parasite-naive calves were randomly alloted to two equal groups and treated with either Doramectin at 200 μg kg −1 or saline prior to mid-season turnout (Day 0) onto contamininated pasture. Faecal egg count was carried out twice weekly from 15 to 64 days after turnout and the cumulative faecal egg count was calculated for each group of calves. In the Doramectin-treated animals, eggs first appeared in the faeces 19 days and 22 days later than in controls for Studies 1 and 2, respectively. Mean cumulative faecal egg counts over the 64 days were reduced in the Doramectin-treated groups by 71% and 87% for Studies 1 and 2, respectively ( P
T L Skogerboe - One of the best experts on this subject based on the ideXlab platform.
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the persistent efficacy of Doramectin pour on against biting and sucking louse infestations of cattle
Veterinary Parasitology, 2000Co-Authors: T L Skogerboe, L L Smith, V K Karle, C L DerozierAbstract:Abstract A repeated-exposure challenge model was used to evaluate the pour-on formulation of Doramectin in preventing the establishment of louse infestations in cattle. Twenty calves cleared of preexisting biting and sucking louse infestations were randomly and equally allocated to either a Doramectin-treated or untreated control group, with five replicates per group. Doramectin pour-on was administered topically at a dose rate of 500 μg/kg body weight. Every 14 days, from a pool of seeder calves with infestations of at least 50 biting and 50 sucking lice each, 10 calves were selected and 1 was placed in each replicate pen. Every week during the 112-day study, 9 predilection sites on the Doramectin-treated and untreated calves were examined to estimate the louse population density. A calf met the infestation criterion for a louse species when two or more live lice were counted on two or more body regions for two consecutive count days. Because only 4 of 10 untreated calves acquired Solenopotes capillatus infestations, the persistent efficacy of Doramectin against S. capillatus was not evaluated. Bovicola bovis and Linognathus vituli infestations in the untreated calves developed shortly after exposure to infested seeder calves. The acquisition of B. bovis and L. vituli infestations in the Doramectin-treated group was delayed for 77 days and 105 days, respectively.
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persistent efficacy of Doramectin and ivermectin against experimental infestations of sarcoptes scabiei var suis in swine
Veterinary Parasitology, 1999Co-Authors: J J Arends, T L Skogerboe, L K RitzhauptAbstract:Abstract Two studies were performed to compare the persistent efficacy of Doramectin and ivermectin in swine experimentally infested with Sarcoptes scabiei var. suis . In the Study 1, 84 pigs were treated with Doramectin, ivermectin, or saline solution on Day 0. Pigs were then challenged with mites on Days 0, 7, 14, 21, 28, 35, or 42. Weekly evaluations were performed for 5 weeks following challenge with mites. Weekly evaluations included physical examination for clinical signs of sarcoptic mange and collection of skin scrapings for determination of mite counts. In the Study 2, 80 pigs were treated with Doramectin, ivermectin, or saline solution on Day 0, and challenged with mites on Days 3, 6, 9, 12, 15, 18, 21, 24, or 27. Weekly evaluations were performed for 6 weeks after challenge exposure. All negative-control (saline-treated) animals in both studies developed evidence of mite infestation. In the Study 1, Doramectin prevented mite infestations 7 days longer than ivermectin. Results from the Study 2 indicated that the persistent efficacy of Doramectin was 18 days on the basis of mite recovery. This was twice as long as the persistent efficacy of ivermectin, which was 9 days on the basis of mite recovery.
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the effectiveness of a single treatment with Doramectin or ivermectin in the control of gastrointestinal nematodes in grazing yearling stocker cattle
Veterinary Parasitology, 1997Co-Authors: Lora Rickard Ballweber, T. A. Yazwinski, L L Smith, J A Stuedemann, T L SkogerboeAbstract:Abstract Four studies were conducted to a similar experimental design in the U.S. to evaluate the effectiveness of Doramectin injectable administered to yearling stocker cattle in the control of gastrointestinal nematodiasis over the subsequent grazing period. Studies were conducted in Wisconsin (WI) and Arkansas (AR) during the summer season. The other two studies were conducted in Georgia (GA) and Mississippi (MS) during the winter/spring season. Doramectin was compared with both ivermectin injectable and ivermectin pour-on in the WI study, with ivermectin injectable alone in the GA study and with ivermectin pour-on alone in the other two studies. At each study site, an area of permanent pasture previously grazed by parasitized animals was subdivided by fencing into equal pasture units each with its own water supply. A treatment designation (non-medicated control, Doramectin injectable, ivermectin injectable or ivermectin pour-on) was randomly assigned to each pasture unit. Weaned beef calves with confirmed gastrointestinal nematode infections were randomly allotted to a pasture unit and corresponding treatment group. Each treatment group consisted of three replicates of seven animals per pasture unit (total 21 animals) in the WI study, three replicates of four or six animals per pasture unit (total 16 animals) in the AR study, five replicates of six animals per pasture unit (total 30 animals) in the GA study and three replicates of 12 animals per pasture unit (total 36 animals) in the MS study. Treatments were 1% Doramectin injectable solution, 1% ivermectin injectable solution, 0.5% ivermectin pour-on solution or non-medicated controls. The injectables were administered at a dose of 1 ml/50 kg body weight (200 μg Doramectin or ivermectin/kg) by subcutaneous injection in the neck. Ivermectin pour-on solution was administered topically at a dose of 1 ml/10 kg body weight (500 μg ivermectin/kg). After receiving their prescribed treatment, animals were placed on their designated pasture unit where they remained for the entire grazing period (84–140 days). Fecal nematode egg counts and body weights were monitored at predetermined intervals throughout each study. Doramectin treatment reduced pretreatment egg counts by between 95 and 100% by 21 days post-treatment. Subsequent rises in egg output from exposure to infective pastures were delayed by two to four weeks resulting in substantial reductions in total egg deposition over the grazing period and, therefore, potential pasture recontamination. Doramectin treatment resulted in substantial average daily weight gain advantages (0.152–0.272 kg) over the grazing season compared to non-medicated controls. Advantages were statistically significant (P 0.05) in average daily gain between the Doramectin and ivermectin injectable or ivermectin pour-on treated groups.
J Moreno - One of the best experts on this subject based on the ideXlab platform.
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Efficacy of injectable Doramectin in the therapy and control of Dermatobia hominis infestations in Latin America.
Veterinary Parasitology, 1995Co-Authors: R A Muniz, O Umehara, J Moreno, Alfredo Coronado, R. Cerqueira-leite, O. Soraci, J ErrecaldeAbstract:Three studies were conducted in Latin America, one in Brazil, one in Venezuela and one in Argentina, using a common protocol to investigate the efficacy of a single subcutaneous injection of Doramectin at 200 μg kg−1 (1 ml per 50 kg) for the treatment and control of Dermatobia hominis infestations in cattle raised under commercial conditions. In each study, two groups of 20 animals each were allocated on the basis of D. hominis nodules present 24 h before treatment to a treated group (T1), or to a control group (T2) which received saline solution at 1 ml per 50 kg of live weight. All cattle were injected in the mid-dorsal cervical region and examined on treatment day and 2, 7, 15 and 30 days post-treatment (p.t.). At each observation day the number of D. hominis nodules was counted and the viability of the larvae inside them was assessed and recorded. Treatment with Doramectin was 100% effective in eliminating D. hominis larvae and in controlling the re-establishment of the parasite under field conditions of continuous reinfestation. During the first 48 h p.t., dead larvae of different ages were found outside or partially outside the nodules in animals of the Doramectin groups. After 48 h p.t., no live larvae were found inside existing nodules, nor did new nodules develop in animals of the Doramectin groups in any of the three studies. When compared with nodule counts in the control group on the same observation day or with parasite burdens on the same animal before treatment, Doramectin-treated animals began to eliminate parasitic nodules at 48 h p.t. Efficacy reached 100% at 7 days p.t. and remained at 100% on subsequent observation days (P
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efficacy of injectable Doramectin in the protection of castrated cattle against field infestations of cochliomyia hominivorax
Veterinary Parasitology, 1995Co-Authors: R A Muniz, O S Anziani, J Errecalde, J Moreno, A Sanavria, Alfredo Coronado, L C B GoncalvesAbstract:Abstract Three studies were conducted in Latin America—one in Venezuela, one in Argentina and one in Brazil—using a common protocol to investigate the efficacy of a single subcutaneous injection of Doramectin in the prevention and control of Cochliomyia hominivorax infestations in castrated cattle. In each study, two groups of 20–28 animals each were allocated to a treated (TI) or to a control (T2) group on the basis of body weights. Animals of TI received Doramectin at 200 μg kg−1 (1 ml per 50 kg) and animals of 72 received saline solution at 1 ml per 50 kg of live weight. After treatment all cattle were castrated surgically. Animals were examined on treatment day and at 2, 4, 6 and 12 days post-treatment. At each observation day, the presence of C. hominivorax infestations was recorded. Doramectin was 100% effective in the prevention and control of screwworm strikes in castrated cattle exposed to continuous field infestations of C. hominivorax in tropical and subtropical areas of Latin America. Over the 12 day duration of the studies, 85%, 60% and 65% of animals in the control groups had infested wounds in Venezuela, Argentina and Brazil, respectively. Affected animals required repeated therapeutic treatment, whereas none of the Doramectin-treated cattle were infested (P
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efficacy of Doramectin in the protection of neonatal calves and post parturient cows against field strikes of cochliomyia hominivorax
Veterinary Parasitology, 1995Co-Authors: R A Muniz, O S Anziani, J Ordonez, J Errecalde, J MorenoAbstract:Abstract Two studies were conducted in Latin America, one in Venezuela and one in Argentina, using a common protocol to investigate the efficacy of a single s.c. injection of Doramectin in the prevention and control of field infestations of Cochliomyia hominivorax in newborn calves and post-parturient cows. In both experiments, pregnant cows were paired on the basis of their calving time. The first cow that calved was assigned to a medicated group, and both cow and calf were treated with Doramectin. The cow received a dose of 200 μg kg−1 and the calf 1 ml of a 1% Doramectin solution. The second cow and calf were assigned to a saline-treated group, and the cow received saline at 1 ml per 50 kg and the calf 1 ml. The procedure was repeated until all animals were allocated to the two treatments. Animals were examined on the treatment day and at 2, 4, 6 and 12 days post-treatment. At each observation day, the navel of newborn calves and external genitalia of the cows were inspected and the presence of C. hominivorax infestations was recorded. Doramectin was 100% effective in the prevention and control of screwworm strikes in newborn calves and in post-parturient cows exposed to continuous field challenge of C. hominivorax. Over the 12 day duration of the studies, 48% and 57% of the saline-treated calves had screwworm navel strikes in the studies in Venezuela and Argentina, respectively. Infested animals required repeated therapeutic treatment, whereas none of the Doramectin-treated calves were affected (P
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EFFICACY OF INJECTABLE Doramectin AGAINST NATURAL BOOPHILUS MICROPLUS INFESTATIONS IN CATTLE
American Journal of Veterinary Research, 1995Co-Authors: R A Muniz, J Errecalde, J Moreno, F. Hernandez, O. Lombardero, R. C. Leite, L C B GoncalvesAbstract:Three experiments were conducted in Latin America--1 in Brazil, 1 in Venezuela, and 1 in Argentina--using a common protocol to investigate the efficacy of a single SC injection of Doramectin (200 micrograms/kg of body weight) for treatment and control of Boophilus microplus infestations in grazing cattle. In each experiment, 2 groups of 20 to 27 cattle were allocated on the basis of tick burdens present 24 hours before treatment to a treated or control group, which received saline solution (1 ml/50 kg). All cattle were injected in the mid-dorsal cervical region and examined on treatment day and on posttreatment days (PTD) 8, 14, 21, and 28. On each observation day, the number of engorged and semiengorged ticks on half of each animals was counted and recorded. Doramectin was highly efficacious in removing tick burdens and controlling reestablishment of B microplus under field conditions of continuous reinfestation. Compared with tick counts in the control group, Doramectin-treated cattle began to eliminate ticks after treatment and efficacy improved on subsequent observation days. In Brazil, efficacy was 91% at PTD 8 and 14, and increased to 99% or higher at PTD 21 and 28. In Venezuela, efficacy was 100% at PTD 8, 14, and 21 and 92% at PTD 28. In Argentina, efficacy progressed from 94.5% at PTD 8 to 99 and 98.5% at PTD 21 and 28, respectively. The reduction of the number of ticks in the Doramectin-treated cattle was significant (P < 0.05) at each observation day.(ABSTRACT TRUNCATED AT 250 WORDS)