Resistance to synthetic pyrethroid pour-on insecticides in strains of the sheep body louse Bovicola (Damalinia) ovis

Groups of sheep infested with strains of Bovicola (Damalinia) ovis were obtained from flocks either with a history of failure to control lice with synthetic pyrethroid (SP) pour-on insecticides, or from farms where SP compounds were not used. The sheep were treated according to the manufacturer's recommendations with registered "off-shears" SP formulations. All treatments were applied under ideal conditions with doses calculated on an individual body weight basis and applied to the dorsal mid-line from the base of the neck to the butt of the tail. Treated sheep were kept in pens and maintained in separate groups. The pour-on SP treatments significantly reduced the lice population but failed to eliminate the infestation in 7 of 13 experiments in sheep carrying strains of lice with resistance factors of greater than 4 to at least one of the SP compounds. Failures occurred with all three of the SP pour-ons currently registered for lice control in NSW and with both water-based and organic solvent-based formulations.     

Efficacy of a 1% lambdacyhalothrin cattle Pour-on (Saber) against sucking and biting lice infesting beef cattle

Four studies were conducted to determine the efficacy of a 1% lambdacyhalothrin pour-on (Saber Pour-on, Schering-Plough Animal Health) for control of sucking lice (Linognathus vituli, Haematopinus eurysternus, Solenopotes capillatus) and biting lice (Damalinia bovis) on beef cattle. Seventy-four mixed-breed cattle naturally infested with one or more species of lice at locations in Wisconsin, Nebraska, Oklahoma, and North Dakota were included in the study. Pretreatment lice samples were taken and identified by genus with the exception that sucking lice were not identified by genus at the North Dakota site. In January or February, half of the cattle at each location received a single application of 1% lambdacyhalothrin pour-on at 10 ml per head for cattle weighing less than 273 kg (600 lb) or 15 ml per head for cattle weighing 273 kg or more. The other cattle at each site served as untreated controls. Lice on designated body areas were counted 2, 4, 6, and 8 weeks after treatment, and the sum of all lice observed on each counting area was reported for each animal. The collective efficacy 6 weeks after treatment against three species of sucking lice (L. vituli, H. eurysternus, S. capillatus) was 88.4% at the Wisconsin site, 92.0% at the North Dakota site, and 100% at the Nebraska and Oklahoma sites. The 1% lambdacyhalothrin pour-on eliminated all biting lice within 2 weeks after treatment, and no biting lice were detected 8 weeks after treatment. A single treatment of 1% lambdacyhalothrin pour-on administered when lice populations were highest (January or February) provided effective season-long control of both biting and sucking lice on cattle.     

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

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 <90% after week 5 at one site. Spinosad spray had the best therapeutic and residual control of all treatments against L. vituli, > 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.     

Efficacy of a pour-on formulation of doramectin against lice, mites, and grubs of cattle

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.     

The persistent efficacy of doramectin pour-on against biting and sucking louse infestations of cattle

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 microg/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.     

Cypermethrin pour-on synergized with piperonyl butoxide: effects on Haematobia irritans (Diptera: Muscidae) natural populations resistant to cypermethrin.

Development of pyrethroid resistance in Haematobia irritans in Santa Fe province, Argentina, resulted in an increased use of pyrethroid insecticides, probably due to lack of suitable alternative treatments. We explored the efficacy of mixtures of cypermethrin and piperonyl butoxide (PBO) against pyrethroid-resistant H. irritans. Groups of 25 Holstein cows each, naturally infested with cypermethrin resistant H. irritans were assigned to treated or control groups in April, September, October and December 1997. Cattle in treated groups were medicated with pour-on oil formulations of 5% cypermethrin (dose = 4 mg per kg of body weight) with 5% or 10% PBO in April, and with a mixture containing 5% of both components thereafter. Efficacy was tested for 21 days after treatment. A treatment of 5% cypermethrin pour-on without PBO was evaluated in October 1997. Samples of horn flies were obtained before September, October and December treatments and exposed for 2 h to filter papers impregnated with different cypermethrin concentrations to determine the 50% lethal concentration (LC50). No difference in efficacy was found between cypermethrin pour-on formulations with 5% or 10% of PBO (more than 94% efficacy on day 21 after treatment). Efficacy of 5 % cypermethrin-5% PBO mixture decreased rapidly in the successive treatments (less than 40% efficacy was observed on day 21 after the December treatment), and the period after treatment with an efficacy higher than 95% was 14 days for the treatment carried out in April, 10 days in September; 7 days for the treatment performed in October and 4 days for the December treatment. The LC50 of cypermethrin was 36.6 microg per cm2 in September and increased to 116.6 and 226.1 microg per cm2 in October and December, respectively. It is concluded that the addition of PBO to cypermethrin did not provide a treatment that would give a long term control of pyrethroid resistant-horn flies.     

The efficacy of injectable and pour-on formulations of moxidectin against lice on cattle

SUMMARY The efficacy of one administration of moxidectin against natural infestations of the 3 common species of cattle lice in Australia: Linognathus vitull, Damallnla bovls and Haematoplnus eurysternus, was determined. A high degree of control of L vituli (too 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 nll 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.     

An evaluation of two cypermethrin-based pour-on formulations on sheep infested with the biting louse, Bovicola ovis

Two synthetic pyrethroid (cypermethrin) based pour-on insecticide formulations, with high cis/trans isomer ratios (80:20) but differing in their respective active ingredient concentrations and solvent component(s), were applied to sheep infested with the biting-louse, Bovicola ovis. All treated sheep were penned with louse-infested sheep 9,12 and 15 weeks after the insecticide was applied. The 2% cypermethrin formulation achieved a higher level of control than the 1.25% cypermethrin formulation at each challenge interval when applied 12 weeks after shearing. The 2% cypermethrin formulation provided 97-100% control of lice from 4 to 16 weeks after application on sheep shorn 6 or 12 weeks prior to treatment. The 1.25% cypermethrin formulation provided 85% control of lice 4 weeks after application on sheep shorn 12 weeks prior to treatment, the level of control increasing to a maximum of 100% by week 9, and declining thereafter. The 2% cypermethrin formulation may provide a better level of control in long-woolled sheep than 1.25% cypermethrin, by compensating for the diluent effect of lipid.     

Warble fly control in France on a national basis

In France, autumn and spring treatments are used for the control of cattle grubs. The autumn treatment consists of pour-on application of one of the following systemic organophosphorus insecticides: 4-tert-butyl-2-chlorophenylmemthyl methylphoporamidate fenthion, O,O-dimethyl phosphorodithioate S-ester with N-(mecaptomethyl)-phthalimide, and trichlorfon. The spring treatment consists of an aqueous preparation of trichlorfon or derris applied to the backs of infested cattle and cattle not treated in the autumn.The autumn treatment is not compulsory, although the Veterinary Services encourage it by providing technical and financial assistance. It was applied to 900 000 cattle in 1973. The spring treatment is compulsory, and the owner pays for it. It was applied to 3 × 10⁶ cattle in 1973.The infestation rate seems to remain at 8–10% in areas where spring treatments have been used for a long time. The rate for the rest of the country is 20% and even there only 8% of the animals have more than five grubs per head.     

Pyrethroid tolerance in the chewing louse Bovicola (Werneckiella) ocellatus

Equine pediculosis is a significant health and welfare issue, particularly in elderly and chronically debilitated animals. Currently infestation is controlled predominantly using topically applied pyrethroid insecticides, allowing limited scope for the rotation of drugs and increasing the risk of selection for resistance. Here the insecticidal efficacies of two pyrethroid-based products against the louse Bovicola (Werneckiella) ocellatus collected from donkeys were examined in vitro. The products were cypermethrin (Deosect?, Pfizer Ltd., 5% (w/v) cypermethrin, cutaneous spray) and permethrin (Switch?, VetPlus Ltd., 4% (w/v) permethrin, pour-on). The pyrethroid efficacy was contrasted with that of the organophosphate diazinon, since the louse populations examined were unlikely to have had prior exposure to this compound. The efficacy of diluted pure permethrin, the excipient, butyl dioxitol and the synergist piperonyl butoxide in the presence of the pyrethroids, were also considered. At the concentrations recommended for animal application, neither 4% (w/v) permethrin, nor 0.1% (w/v) cypermethrin had any significant effect on the mortality of B. ocellatus and neither induced significantly more mortality than an acetone-only control. In contrast, 0.04% diazinon caused 70% mortality within 4h and 100% mortality after 24h exposure. The addition of a potential pyrethroid synergist, piperonyl butoxide, in combination with cypermethrin and permethrin, resulted in no significant increase in mortality. It is concluded that the population of lice tested display a high level of pyrethroid tolerance which is likely to reflect the development of resistance. Twenty-four hours after routine treatment of 10 donkeys with a pour-on permethrin product (Switch?, VetPlus Ltd., 4% (w/v) permethrin, pour-on) hair tufts taken from their flanks were not significantly insecticidal compared with hair from the midline application site, implying a low level of insecticide distribution. Such a distribution pattern is likely to create an insecticide concentration gradient over the body and further facilitate selection for resistance.     

An evaluation of two cypermethrin-based pour-on formulations on sheep infested with the biting louse,Bovicola ovis

Two synthetic pyrethroid (cypermethrin) based “pour-on” insecticide formulations, with high cis/trans isomer ratios (80:20) but differing in their respective active ingredient concentrations and solvent component(s), were applied to sheep infested with the biting-louse, Bovicola ovis. All treated sheep were penned with louse-infested sheep 9, 12 and 15 weeks after the insecticide was applied. The 2% cypermethrin formulation achieved a higher level of control than the 1.25% cypermethrin formulation at each challenge interval when applied 12 weeks after shearing. The 2% cypermethrin formulation provided 97-100% control of lice from 4 to 16 weeks after application on sheep shorn 6 or 12 weeks prior to treatment. The 1.25% cypermethrin formulation provided 85% control of lice 4 weeks after application on sheep shorn 12 weeks prior to treatment, the level of control increasing to a maximum of 100% by week 9, and declining thereafter. The 2% cypermethrin formulation may provide a better level of control in long-woolled sheep than 1.25% cypermethrin, by compensating for the diluent effect of lipid.     

Therapeutic efficacy of zeta-cypermethrin pour-on for the treatment of biting and sucking lice in cattle under field conditions

OBJECTIVE: To assess the efficacy of zeta-cypermethrin pour-on to control cattle lice. DESIGN: Five field trials in south-eastern Australia. PROCEDURE: Zeta-cypermethrin pour-on, deltamethrin pour-on and pour-on vehicle were applied to groups of 10 cattle. Lice were counted before treatment and 14, 28, 42 and 56 days after treatment. RESULTS: Zeta-cypermethrin pour-on given at 2.5 mg/kg was equivalent to, or marginally more effective than a deltamethrin pour-on at 0.75 mg/kg. It eliminated B bovis and H eurysternus and gave good control of L vituli and S capillatus. Zeta-cypermethrin at 1 mg/kg gave good control of B bovis and H eurysternus but was not satisfactory against L vituli and S capillatus. CONCLUSION: Zeta-cypermethrin pour-on, given at 2.5 mg/kg, is an effective treatment for cattle lice control. Zeta-cypermethrin, and other synthetic pyrethroid pour-ons, are the treatment of choice to control B bovis.     

Keratoconjunctivitis and periorbital papillomatosis associated with heavy periorbital infestation by the tail louse Haematopinus quadripertusus in heifers

Heifers (Israeli-Holstein), aged 12-18 months, permanently maintained in open barns on an inadequate nutritional regime were found to be moderately to heavily infested by Haematopinus quadripertusus, the tail louse. The severely infested heifers showed keratoconjunctivitis and periorbital papillomatosis. Two treatments with an alpha-cypermethrin pour-on product 14 days apart controlled the lice, and were followed by alleviation of the inflammation and regression of the papillomas.     

Impact of the duration of control of cattle lice with eprinomectin on leather quality

The relationship between lice infestation in calves during their first winter and damage to the leather produced was investigated in a trial involving 500 calves, 100 of which were treated with a pour-on endectocide during the first winter. All the calves received routine lice treatment in the second winter and were reared to slaughter weight. The hides were removed at the abattoir, tanned, inspected for lice-related damage, and graded according to their suitability for the production of high quality leather. The untreated group developed natural infestations of the chewing louse (Bovicola bovis) during the first winter but none was observed in the second winter. Hides from cattle infested with lice in their first winter had higher levels of lice damage than hides from those treated with eprinomectin, at both the chrome-tanned and dried dyed-crust stages of leather production.     

Potential demand for a mixed public-private animal health input: evaluation of a pour-on insecticide for controlling tsetse-transmitted trypanosomiasis in Ethiopia

The new pour-on insecticides that can be used to control tsetse-transmitted trypanosomiasis confer benefits to the owners of the cattle given treatments and other people keeping cattle in areas affected by the control. A study was conducted in southwest Ethiopia to assess farmers' perceptions of the public and private benefits of the pour-on and identify the household-level factors affecting its demand. Ninety-seven percent of the 166 survey respondents had received pour-on treatments when they were free and 67% paid for treatments the month before the survey. Farmers noted public and private benefits from using the pour-on, the most important of which were less trypanosomiasis, fewer problems with biting flies (including tsetse), and fewer problems with ticks. The probit model estimated to quantify the effects of different variables indicates that proportions of cows and oxen, distance to the treatment centre, and seasonal factors were significant determinants of demand.     

Treatment of natural infestations of the biting louse (Werneckiella equi) on horses using triflumuron, a benzoylurea derivative insect growth regulator

The horse biting louse (Werneckiella equi) is a common global equine ectoparasite. To our knowledge, benzoyl(phenyl)urea insecticides (triflumuron, diflubenzuron) commonly used as sheep lousicides, have not been evaluated for efficacy against W. equi. The aim of this study was to determine louse control efficacy, general wellness and dermal safety following triflumuron application as a backline pour-on to horses. Two efficacy trials using 25 adult naturally infested lousy horses, and a dermal safety trial using 10 adult louse-free horses were conducted over a 14-month period. Lousy animals were selected by assessment of their lice status prior to treatment. For the efficacy trial, the triflumuron product was applied at a dose of 2.5mg triflumuron per kg bodyweight (1 mL product per 10 kg bodyweight). For the safety study, triflumuron was applied at a 3x clinical dose of 7.5 mg triflumuron per kg bodyweight (3 mL product per 10 kg bodyweight). In our first efficacy trial, 100% lousicidal efficacy was achieved by day 44 post-treatment. In our second trial, no lice were identified on horses by day 71 post-treatment. In the safety trial, no adverse effects were seen. Results of this study demonstrate that the off-label, experimental pour-on application of triflumuron at 2.5 mg/kg bodyweight is convenient, highly effective and safe (at 3x the clinical dose) for the treatment of the horse biting louse, W. equi.     

Efficacy of Flumethrin Pour-On Against Damalinia caprae of Goats (Capra hircus)

Goats naturally infested with Damalinia caprae lice were used to evaluate the efficacy of flumethrin pour-on. The maximum load of lice infestation was detected in the neck region. The LC₅₀ value of flumethrin pour-on against D. caprae was found to be 119.35 ppm and the 95% confidence limits were calculated to be 104.10 and 136.85 ppm. Flumethrin at the rate of 1 mg/kg body weight by pour-on application along the mid-dorsal line was found to be 100% effective in treating lice-infested goats compared with the control goats. The residual action of flumethrin was found to be at least 42 days during which period no apparent signs of any local or general adverse effects were observed. Based on these studies, it is suggested that flumethrin pour-on may be successfully used for both the prophylaxis and treatment of D. caprae infestation in goats and it is necessary to repeat the treatment after 42 days. The method of application is highly advantageous as it can be conveniently applied, even in animals with thick hair coat and during the winter months.     

The application of moxidectin formulations for control of the cattle tick (Boophilus microplus) under Queensland field conditions

Objective To assess the control of the cattle tick (Boophilus microplus) and the performance of commercial cattle treated with the macrocylic lactone endectocide, moxidectin, formulated either as an injection or as a pour-on. Design Groups of 10–12 tick infested cattle were treated with moxidectin injection, moxidectin pour-on or remained untreated (28-day trials) or were treated with deltamethrinethion as a dip (140-day trials). The cattle were exposed to natural tick challenge under field conditions. Procedure Tick numbers on trial cattle were recorded in each trial before the initial treatment and in the 28-day trials at 7, 14, 21 and 28 days or in the 140-day trials, at 28-day intervals before each of the treatments and at the final inspection. Body weights of the cattle were also recorded prior to the initial treatment and at the termination of each trial. Cattle were observed on the day of each treatment and at each inspection for evidence of any reactions to treatment. Results 28-day trials: Significant reductions in tick counts were recorded in both treatment groups when compared with cattle in the untreated group. Weight advantage was recorded in the moxidectin treated groups. 140-day trials: All three treatments resulted in zero or low tick counts at each inspection with the exception of the pour-on treatment at week 8 in one trial and week 9 in the other trial. Additional weight gain was recorded for both the moxidectin treated groups, relative to the deltamethrin-ethion dip groups, but was significant only for the pour-on groups. There was no evidence of any local or systemic adverse reaction in any treated cattle in any trial. Conclusion Good to excellent control of the cattle tick (Boophilus microplus) was demonstrated with the moxidectin formulations in all trials, the injection being particularly effective. An improved performance was recorded in all trials in cattle treated with both moxidectin formulations when compared with the untreated cattle and with cattle treated with the deltamethrin-ethion dip. There was no evidence of any local or systemic adverse reaction to treatment with either moxidectin formulation.     

EFFICIENCY AND SAFETY OF METHIDATHION APPLIED AS A POUR-ON SYSTEMIC INSECTICIDE FOR CONTROL OF CATTLE LICE

Methidathion applied to cattle as a pour-on insecticide for control of lice (predominantly Linognathus vituli, but also Haematopinus eurysternus and Damalinia bovis) caused a reduction in the lice population of approximately 98% to 99% in laboratory trials at the minimum recommended dose of 4 mg/kg and a 98.8% to 100% efficiency was achieved in field trials. In a comparative efficiency trial in the laboratory methidathion at 3.5 to 5 mg/kg reduced the lice population by 98.8% to 99%, fenthion by 98.5% at 4.5 mg/kg and famphur by 99.7% at 16.5 mg/kg. Methidathion was tolerated by calves aged 15 to 20 weeks at dose rates up to 40 mg/kg indicating an approximate 7 fold safety margin, but 1 of 4 calves treated at 50 mg/kg died following treatment. Treatment with fenthion at 50 mg/kg, 7.4 times the average recommended rate, famphur at 75 mg/kg, 3 times the average rate and chlorpyrifos at 85 mg/kg, 5 times average rate, caused reductions in whole blood cholinesterase activity of 52%, 27% and 47% respectively which were similar to the reductions in cholinesterase activity found in calves treated with methidathion at similar levels above the recommended commercial dose rates. It was found that 2 day old calves were more sensitive to treatment with methidathion than calves 9 or 16 days old. A further 11,900 cattle of varying age, breed and sex were treated with methidathion under field conditions at the recommended rate of 4 to 8 mg/kg, and 534 cattle were treated at 24 mg/kg without any signs of toxicity.     

The efficacy of formulations of triclabendazole and ivermectin in combination against liver fluke (Fasciola hepatica) and gastro-intestinal nematodes in cattle and sheep and sucking lice species in cattle

OBJECTIVE: To assess the efficacy of two formulations of triclabendazole and ivermectin in combination against liver fluke (Fasciola hepatica), gastro-intestinal nematodes and sucking louse species in cattle and sheep. PROCEDURE: A study of 540 cattle and 428 sheep at 18 sites throughout Victoria and New South Wales was undertaken. At each site, one group of cattle or sheep was treated with a combined formulation (Fasimec Cattle or Fasimec Sheep), another received ivermectin and triclabendazole separately. In trials on lice infestation, an additional group remained untreated. Samples for faecal egg counts were collected on days -7, 0 (treatment day), +7, +14 and +21 after treatment. Lice assessments were carried out on days -7, 0, +7, +14, +28, +42 and +56. RESULTS: Both treatments were highly efficacious (> 98% efficacy) against liver fluke in cattle and sheep, against three sucking lice species of cattle and against gastro-intestinal nematodes in sheep. There was also no significant difference between treatments in efficacy. Against gastro-intestinal nematodes, Fasimec Cattle was significantly (P < 0.01) more effective than the separately applied ivermectin and triclabendazole treatment. Mean efficacy for the Fasimec Cattle and Ivomec/Fasinex 120 groups respectively, was 97.6% and 94.2% on Day +7, 98.9% and 91% on Day +14 and 98.5% and 92.6% on Day +21. CONCLUSION: The efficacy of Fasimec' Cattle and Fasimec Sheep was at least equal to that of currently registered products (with the same active ingredients) used to control these parasites.