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.     

Persistence of cattle grubs (Diptera: Oestridae) on a Canadian ranch with long-term, continuous therapeutic control

Sero-prevalence of cattle grubs (Diptera: Oestridae) was monitored on two large western Canadian ranches from 1992 to 1999. One ranch has had a long-term programme for therapeutic control of cattle grubs as required by legislation in the province of Alberta. The other ranch, located in southeast Saskatchewan, has not used any treatment for grub control for an extended period of time. Serum from calves was tested each fall for the presence of antibodies to Hypoderma spp. using an ELISA. Percent positive sera on the Ranch 1 ranged from 8.0 to 73.3%. There was substantial variation among years and among two separate herds maintained on the ranch. Percent infested calves on the Ranch 2 ranged from 76.5 to 99.0%. Improved surveillance for cattle grubs using serological techniques is the only effective means to monitor the status of this important parasite.     

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.     

Toxicity of Sevin (1-Naphthyl-n-Methyl-Carbamate) To Cattle Grubs, Lice, and Cattle

Sevin, a cholinergic insecticide, was used for the control of cattle lice Haemotopinus eurysternus and Bovicolar bovis and cattle grubs Hypoderma lineatum and H. bovis. Partial or complete spraying of the animal body with 0.5 per cent Sevin was equally effective for louse control and one application killed the lice and prevented reinfestation in `carrier' cows for 17-20 weeks.

The dermal or parenteral administration of Sevin to the host animal had no larvicidal effect on cattle grubs migrating in its body. Similarly, the sprays of Sevin had no lethal effect on grubs encysted in the back of cattle.

     

Detection of circulating hypodermin C: an antigen capture ELISA for diagnosis of cattle grub (Diptera: Oestridae) infestations

An antigen capture assay for the detection of circulating hypodermin C was developed for diagnosis of hypodermosis. A murine monoclonal antibody to recombinant hypodermin C was raised using rapid immunization and a one-step hybridization-cloning technique. A highly reactive, specific monoclonal antibody was tested using sera spiked with known quantities of purified, native hypodermin C or with recombinant hypodermin C. Sensitivity of 96.4% and specificity of 95.6% for the antigen capture assay was assessed using a panel of sera from animals unexposed to cattle grubs and from cattle with palpation proven cattle grub infestations. Data from this panel of sera was used to establish the cut-off OD for further testing. The kinetics of circulating hypodermin C was assessed using the assay in three groups of cattle artificially infested with 50, 100 or 200 first instar Hypoderma lineatum. Antigen was first detected approximately 6 weeks after infestation. The amount of antigen detected increased in each group of animals reaching peaks at different times in each group. Levels of antigen fell quickly following arrival of grubs at the back and completion of the molt to second instar.     

The feasibility of exterminating warble flies (Hypoderma spp.) on a regional basis

A program to exterminate warble flies (Hypoderma lineatum and H. bovis) was begun in Wetaskiwin County, Alberta, Canada, in 1968 and has since been adopted by nearly all the local authorities (countries, municipalities, etc.) in Alberta, which has an area of about 650 000 km². Except for lactating cows, which were treated with rotenone, all the cattle in the program were treated annually with systemic insecticides.The program has been under continuous evaluation in Wetaskiwin County where the mean numbers of warble grubs in untreated cattle were 9.0, 6.9, 3.4, 0.2, 2.5 and 1.4 in 1969–1974, respectively. In 1973 and 1974, the infestation was found mainly in one of the seven divisions of the county. That division did not receive adequate surveillance.The extermination of warble flies would be feasible in other areas if the procedures adopted in the Alberta program were carried out for a minimum period of 3 years and were followed by spring treatment of infested herds for several years. The recommended spring treatment is usually required for the control of cattle lice anyway.     

Eradication of warble flies in West Germany

Since derris preparations applied in compliance with a government directive of 1933 failed to control warble flies, a new law to enforce treatment with systemic insecticides was passed in the Federal Republic of Germany in 1967. Under this law, the owners must treat their cattle with systemics before the grazing season starts if hypodermal grubs are found on even a single animal in the herd. The law authorizes state governments to decree that all cattle in a state or in certain regions be treated at a certain time. All states with pasture areas have exercised this right.The grazing season runs from May to October and the cattle are stabled thereafter. The treatment period is mandated after the grazing season, at the beginning of December. If warbles are observed before the cattle are turned out to pasture, a second treatment of all the cattle on the farm is mandatory. Through this procedure, warble infestation has been greatly reduced. In some areas, the infestation has been eradicated completely and is not seen either on live animals or on the hides of slaughtered cattle. The level of infestation at which it is safe to abandon autumn treatment without risking a resurgence of the infestation has not been determined.     

New methods of applying drugs for the control of ectoparasites

A brief history of the development of methods used to apply drugs (commonly called insecticides or acaricides) to domesticated animals for the control of ectoparasites is presented. The focus is on methods used in the United States for treating cattle, sheep and goats, and swine. Details of the evolution of treatment methods are presented for lice, flies, cattle grubs, keds, ticks, and other arthropods. In general, treatment methods have undergone some change over the years; while, in contrast, treatment materials have changed considerably. Three trends in treatment methods become obvious - (1) Gradual reduction in the amount of treatment material applied dermally from spray or dip to pouron, to spoton, and to insecticide-impregnated ear tags, (2) Increasingly wider use of animal systemic insecticides administered orally or percutaneously to control a variety of ectoparasites, and (3) The development of new methods (sustained release devices) to lengthen the residual effectiveness of treatments. Unfortunately, lengthened residual effectiveness may lead to resistance of important ectoparasites to the treatment materials.     

Ivermectin as an antiparasitic agent in cattle

In experimental trials on cattle, ivermectin given SC at 200 micrograms/kg had 95% or better efficacy against adult and immature GI and pulmonary nematodes, including inhibited fourth-stage larvae of Ostertagia ostertagi. Studies of efficacy against ectoparasites revealed nearly 100% efficacy against sucking lice, psoroptic and sarcoptic mange mites and cattle grubs. Safety trials revealed no adverse effects with the recommended dosage, including bulls and pregnant cows. A few grub-infested cattle died from acute esophagitis associated with a host-parasite reaction after ivermectin injection.     

Post-Treatment Reactions in Cattle During Extensive Field Tests of Systemic Organophosphate Insecticides

Treatment, grub infestation, and post-treatment reaction data is given for 11,537 range-managed beef cattle, of all age classes, treated for grub and louse control with various systemic organophosphate insecticides during the period 1956 to 1964. Two cows died from perforation of the throat during administration of Trolene boluses. Of 6,858 calves, 71 showed adverse reactions with 4 dead. Of 4,679 cattle over one year of age, 3 showed adverse reactions with one death. No typical organophosphate poisoning occurred. One death resulted from a paraplegic reaction and necropsy showed spinal nerve damage of the type often associated with the presence of H. bovis grubs in the spinal canal. Seventy-three reactions, with 4 deaths, were of a bloat-salivation type, and necropsies of 3 indicated anaphylaxis, the other an extensive pharyngeal — esophageal necrosis. Reactions were directly associated with grub abundance. Other stress factors coincident to insecticide treatment, such as Bang''s vaccination and dehorning, did not enhance reactions, and incipient coccidiosis did not predispose to reactions, nor did insecticide treatment increase susceptibility to coccidiosis. It is concluded that the observed adverse reactions resulted from the killing of grubs situated in the animal tissues.     

Control of cattle grubs with fenthion pour-on and trichlorfon spot-on in Germany

Field tests in northern Germany showed that fenthion pour-on and trichlorfon spot-on are suitable for the control of cattle grubs. The advantage of these two methods of application compared with other methods is the exact, easy, and time-saving applicationField tests indicate that fenthion (Tiguvon) pour-on is highly effective againsts the migrating first instar and the second and third instars. Trichlorfon (Neguvon) spot-on was also highly effective against the migrating first instar but showed a lower efficacy against the second and third instars. It is suggested that the second and third instars are killed more reliably by direct contact with the compound. This contact is easier to achieve by the pour-on than by the spot-on method.Under German conditions, the following treatment plan is suggested: application of fenthion pour-on or trichlorfon spot-on in the autumn and, if required, fenthion pour-on in the spring. Since cattle eliminate trichlorfon faster than fenthion, application of the former may be preferable in certain cases.     

皮蝇幼虫在牦牛体内移行动态与伊维菌素最佳驱除时间

2004年经剖检60头幼年牦牛,对牛皮蝇幼虫在牦牛体内移行动态进行了观察。8月份,第一期幼虫在牦牛体内出现,10月中旬牦牛体内第一期幼虫呈高峰。从11月中旬到第二年2月中旬第二期幼虫出现,元月中旬二期幼虫出现高峰,三期幼虫从元月中旬到6月初出现,3月中旬出现高峰。用伊维菌素给45头幼年牦牛投药:9月中旬,10月中旬和11月中旬各15头。9月中旬和11月中旬的投药群,在12月中旬均出现瘤疱,而10月中旬的投药群未发现瘤疱,表明10月中旬对第一期幼虫为最佳驱除时间。     

Progress in extermination of cattle grubs (Hypoderma spp.): Summary of the symposium

A symposium on “Extermination of Cattle grubs (Hypoderma spp.)” was organized at the Seventh International Conference of the World Association for the Advancement of Veterinary Parasitology held at Thessaloniki, Greece, on 14–16 July 1975. The symposium dealt mainly with regional or national programs now operating for examination of cattle grubs in several countries, including Canada, Eire, the Federal Republic of Germany, France, Northern Ireland, Switzerland, and the U.S.S.R. Besides the papers published in this issue, papers were also presented on “Warble Fly Eradication in Eire” (Thornberry, 1975); “Changes in Immune Response to Hypoderma spp. in Cattle Treated With Fenthion” (Boulard, 1975); and “Eradication of Hypodermosis: Alternatives and Auxiliaries to Chemical Control Treatments” (J. Weintraub, unpublished data).     

Effect of Droncit (Praziquantel) on Yellow Grubs Clinostomum marginatum and Eye Flukes Diplostomum spathaceum in Channel Catfish

Abstract

Channel catfish Ictalurus punctatus with infections of yellow grubs Clinostomum marginatum and eye flukes Diplostomum spathaceum were treated with 2 mg Droncit (praziquantel)/L in a water bath for 2 and 4 h. At the time of treatment, 80% of the fish had visible yellow grubs and 70% had opaque eyes. Fourteen days after treatment, 40.1% of the yellow grubs in the 2-h treatment were dead. No grubs were dead in the 4-h treatment; however, the number of yellow grubs was reduced in the treated fish. No dead eye flukes were seen in untreated fish after 14 d, but 59.2 and 44.4% of eye flukes in the 2- and 4-h treatments, respectively, were dead. At 21 d, the percentages of dead eye flukes were 86% (2 h) and 90.1% (4 h). Droncit had limited effect on yellow grubs in channel catfish, but the chemical had a beneficial effect of reducing numbers of eye flukes.     

Blood Thiamin Concentrations in Bovine Polioencephalomalacia

Thiamin concentrations were determined by the thiochrome method in blood from 16 cattle with polioencephalomalacia (PEM) or other apparent central nervous disorders. The mean blood total thiamin concentration of the five cattle with PEM (20.5 ± 5.1 µg/100 ml blood) was not significantly different from concentrations in the cattle with the other disorders, despite evidence of a thiamin diphosphate deficiency reported in cattle with PEM.     

Stage specific mortality and humoral immune responses during pulse and trickle infestations of the common cattle grub, Hypoderma lineatum (Diptera: Oestridae)

Stage specific survival of larvae and pupae of the common cattle grub, Hypoderma lineatum de Villers, was compared in cattle artificially infested with larvae delivered by subcutaneous injection as a single infestation of 100 larvae, in trickle infestations of either two doses of 50 larvae, separated by 15 days, or in four doses of 25 larvae, separated by 9, 6, and 6 days, respectively. The duration of the migratory and 'warble' phases were also compared between treatments. The kinetics of the antibody response was monitored throughout the larval development by ELISA. No difference was noted in the level of antibodies among the three treatments. Mortality of first-instars differed among the infestation groups with mortality in the single pulse infestation group相似文献   

Hidden antigens from third instar Hypoderma lineatum: impact of immunization on larval survival in artificial infestations

Soluble fractions of Hypoderma lineatum third instar fat body, haemocytes and haemolymph were formulated with Quil A and used to immunize four groups of calves while a fifth group remained untreated. Calves received two subcutaneous injections of the soluble fractions, or adjuvant only delivered two weeks apart. Two weeks after the last injection the calves were exposed to 50 newly hatched larvae of H. lineatum which were placed on the skin and allowed to penetrate. Survival of larval stages was monitored by weekly palpation and collection of emergent third instars. Antibody responses to the immunogens were evaluated by immunoblots and following infestation antibody responses to first instar antigens were evaluated by an ELISA. Non-immunized calves and calves injected with adjuvant were all palpation positive for cattle grubs. In groups immunized with fat body, haemocyte and haemolymph components 100%, 33% and 33% were palpation positive for grubs respectively. First instar mortality, as reflected in palpable grubs, was high in the groups receiving injections with tissue components (99.3%, 95.1%, 95.8%, 83.9 and 80.4% mortality for those groups receiving fat body, haemocyte, haemolymph, adjuvant or control respectively). Second and third instar mortality was also higher in the immunized groups (100.0%, 91.7%, 91.7% for fat body, haemocyte, and haemolymph respectively) in comparison to the adjuvant only (14.0%) and unvaccinated (33.3%) groups. No viable flies emerged from pupae originating from larvae emergent from any of the immunized groups. Calves receiving the tissue extracts developed antibodies to several protein components following the second immunization which were still present 13 weeks post-infestation. Several proteins appeared to be common among the three tissue extracts and were recognized by antibodies from the immunized calves. All groups of calves became positive for antibodies to first instar antigens, although in some immunized calves the antibodies were transient.     

Eradication of Hypoderma species in Northern Ireland

The field measures for the control and eradication of the warble fly in Northern Ireland are described. The level of infestation and the main economic losses before the introduction of these measures are indicated. The limitations of the control measures used before the introduction of systematic insecticides are discussed.A limited field trial with a systematic insecticide was conducted in 1964, but the main national programme for warble control was implemented in 1966 and 1967. Under the programme, the treatment of all cattle was compulsory.The nature and organization of the programme and its staffing and cost are described. The field monitoring, the extent and nature of adverse reactions in some of the treated animals, the effects on the rate of warble infestation, and the current status of “warbles” as a Notifiable Disease are discussed. Also described is the practicality of the eradication of cattle grubs from the Island of Ireland as a whole through synchronization of the warble control programmes in Northern Irelabnd and Eire.     

Efficacy of ivermectin in a topical formulation against induced gastrointestinal and pulmonary nematode infections, and naturally acquired grubs and lice in cattle

Efficacy of ivermectin in a topical formulation was evaluated in cattle against adult gastrointestinal and pulmonary nematode infections (experiment 1, n = 24), the 2nd- and 3rd-stage larvae of Hypoderma spp (experiment 2, n = 12), and the biting louse Damalinia bovis (experiment 3, n = 12). Nematode infections were induced and grubs and lice were naturally acquired. Treatments consisted of a single dose of ivermectin in a topical formulation of 200, 500, or 1,000 micrograms/kg of body weight in experiment 1 or 500 micrograms/kg in experiments 2 and 3. At 1,000 micrograms/kg, ivermectin was 100% effective against Ostertagia ostertagi, Trichostrongylus colubriformis, Oesophagostomum radiatum, Nematodirus helvetianus, Haemonchus placei, and Dictyocaulus viviparus and was greater than 99% effective against Cooperia oncophora, C punctata, and T axei. At 500 micrograms/kg, the efficacy was 100% against C oncophora, C punctata, O ostertagi, T axei, Oes radiatum, N helvetianus, Haem placei, and Dict viviparus and greater than 99% against T colubriformis. At 200 micrograms/kg, the efficacy was 100% against Oes radiatum, Haem placei, and Dict viviparus, greater than 99% for O ostertagi, 96% for C oncophora, 86% for C punctata, 90% for T axei, 85% for T colubriformis, and 71% for N helvetianus. At 500 micrograms/kg, ivermectin was highly effective against the grubs Hypoderma bovis and H lineatum and eliminated the louse Damalinia bovis.     

Evaluation of an antigen capture ELISA for the early diagnosis of Hypoderma lineatum in cattle under field conditions

An antigen capture or sandwich ELISA (sELISA) was evaluated for the diagnosis of Hypoderma lineatum in cattle under field conditions in northwestern Spain. The kinetics of circulating hypodermin C (HyC) and specific antibodies during the course of natural infestation were determined in a group of 10 Frisian calves. In addition, oesophagi and blood samples were taken from 105 cows at a slaughterhouse in order to compare three methods for the diagnosis of H. lineatum: sandwich ELISA for the detection of the antigen HyC (sELISA), indirect ELISA for the detection of antibodies anti-HyC (iELISA) and the detection of first instars (L1) in the oesophagus. In naturally infested cattle, HyC was present in circulation at low levels during the early and late phases of the infestation. However, in the middle phase, coinciding with the presence of L1 in the oesophagus, two peaks of increased HyC concentration were observed. Specific antibodies increased progressively until the first appearance of larvae in warbles on the back. There was no correlation between antigen or antibody levels and the number of grubs in the back. Prevalence of first instars in the oesophagi of slaughtered cows was 21.9% (23/105). The percentage of cattle that were positive for circulating antigen was slightly higher (24.8%), suggesting the recent destruction of migrating larvae in some animals. However, there was no correlation between the number of L1 and HyC levels. With the iELISA, 79% of the animals were positive to Hypoderma, which means that a high percentage of those animals have been exposed to the parasite but they had no apparent current infestation. The sELISA is a good tool to follow larval development within the host; however, the episodic elevation of HyC levels limits the usefulness of this test for the early diagnosis of Hypoderma under field conditions.