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1.
The efficacy of eprinomectin in an extended-release injection (ERI) formulation was determined in cattle harboring naturally acquired infestations of first- or second- and third-stage larvae of Hypoderma spp. in three studies conducted according to the same protocol in the USA (two studies) and Germany (one study). Thirty cattle sourced from herds with a history of Hypoderma infestation were included in each study. Cattle were formed into replicates of three animals each on the basis of pre-treatment anti-Hypoderma antibody titers. Within replicates each animal was randomly allocated to one of the following treatments: ERI vehicle (control) at 1 mL/50 kg bodyweight, administered once on Day 0; Eprinomectin 5% ERI at 1 mL/50 kg bodyweight (1.0 mg eprinomectin/kg), administered once on Day 0 (when larvae were expected to be first instars); or Eprinomectin 5% ERI at 1 mL/50 kg bodyweight (1.0 mg eprinomectin/kg), administered once when larvae were second or third instars (study dependent, Day 73, 119, or 140). Treatments were administered by subcutaneous injection in front of the shoulder. In all studies, emerging and/or expressed Hypoderma larvae were recovered, speciated, and counted and viability was determined. Eprinomectin LAI treatment was 100% (p < 0.05) efficacious against first- and second- or third-stage larvae of Hypoderma bovis (two studies) and Hypoderma lineatum (one study). All animals accepted the treatment well. No adverse reaction to treatments was observed in any animal in any study. 相似文献
2.
Hatice Cicek Hasan Cicek Mustafa Eser Murat Tandogan Hıfzı Oguz Sarımehmetoglu 《Tropical animal health and production》2011,43(1):17-20
This study was carried out to investigate the prevalence and economic losses due to in cattle of hypodermosis between May
2008 and April 2009 in Afyonkarahisar province of Turkey. A total of 6,598 cattle—3,498 in pasture and 3,100 in slaughterhouse—were
examined for hypodermosis. One hundred ninety-five out of 6,598 cattle (2.96%) were found positive. Concerning this infestation
rate, the prevalence of hypodermosis in field was 5.3%, whereas the prevalence was 0.3% in slaughter house. Hypoderma bovis and Hypoderma lineatum were recorded in slaughter house. First-stage Hypoderma spp. larvae weren’t found in cattle organs in slaughterhouse. The annual economic loss on skins is estimated to be about
18,288 TL (currency exchange rate is 1 USD:1.499 TL). 相似文献
3.
In France, farm workers are occasionally infested with the larvae of Hypoderma lineatum and H. bovis, which are primirily parasites of cattle. A specific serological test for diagnosing human cases is described here.The immunological responses in cattle are directed mainly against the proteolytic secretion of the first instar larvae. This secretion was used as an antigen for the diagnostic immuno-electrophoretic test in man. The antigen was highly specific and produced negative results to human sera from 108 patients with other forms of parasitoses and 23 non- parasitized controls.We report here on 13 cases of Hypoderma infestation in man. Ten of these were positive and three negative to the test. In the negative cases, the serum was collected 1–2 months after the emergence of the larvae. The immunological response disappeared rapidly after larval emergence; in one case within 9 days. 相似文献
4.
Bilge Karatepe Mustafa Karatepe Ayşe Çakmak Zafer Karaer Gül Ergün 《Tropical animal health and production》2009,41(1):109-113
The prevalence of equine piroplasmosis caused by Theileria equi and Babesia caballi in Nigde, in central Anatolia, Turkey has remained unknown. Serum samples were obtained from a total of 125 horses and were
tested for antibodies to T. equi and B. caballi using the Indirect Fluorescence Antibody Test (IFAT). Twenty-three (18.4%) horses were seropositive for equine piroplasmosis.
Anti-T. equi was observed in 16 horses (12.8%) while anti-B. caballi was detected in 12 horses (9.6%). In addition, 5 serum samples were positive for both parasites. The prevalence rates of
antibodies to T. equi and B. caballi for female and male horses were statistically indifferent (p = 0.19 and 0.90). The difference between the seropositivity
rates to T. equi among age groups was statistically insignificant (p = 0.44) while the difference to B. caballi among age groups is statistically significant (p = 0.01). Seropositivity rates ranged from 2.9% to 25.7% for T. equi and 2.9% to 14.3% for B. caballi from the selected districts in Nigde. A statistically significant difference on seropositivity rates for the study sites
was observed for only T.equi (p = 0.03). This study indicates that T. equi is higher than B. caballi in Nigde.
This study was supported by the Scientific Research Projects Unit of Nigde University (FEB 2007/08). 相似文献
5.
V. Dacal D.D. Colwell C. Lpez V. Prez L. Vzquez S. Cienfuegos P. Díaz P. Morrondo P. Díez-Baos R. Panadero 《Veterinary immunology and immunopathology》2009,131(1-2):59-64
Local and systemic cytokine responses were studied in 3 groups of cattle, with 4 animals each, experimentally infested with Hypoderma lineatum (De Villers) first instars (L1). The first group was undergoing a primary infestation (G-1), the second group was undergoing a secondary infestation (G-2) and the third group was infested for their third consecutive year (G-3). Cattle were infested with 25 L1 deposited on the skin. Blood and skin samples were taken at 0, 6, 12, 48, 96 and 144 h post-infestation (h.p.i.). Interleukin 10 (IL-10), IL-4 and interferon gamma (IFN-γ) production was studied by immunohistochemistry and sandwich ELISAs. IL-4+ cells showed a significant increase at 6 h.p.i. in both reinfested groups (G-2 and G-3) when compared with G-1. In all groups the number of IL-4+ cells decreased significantly at 48 h.p.i. IL-10+ cells increased in G-1 at 6 and 48 h.p.i., whereas in both reinfested groups increased at 12 h.p.i. with a peak at 48 h.p.i. IFN-γ+ cells showed a significant increment at 6 h.p.i. in all groups, followed by a rapid descent at 12 (G-1 and G-2) and 48 h.p.i. (G-3). Penetration of the skin by H. lineatum did not have any significant effect on IFN-γ serum concentrations and, except for IL-10 there were no correlation between local production and serum concentrations of cytokines. The increase of both Th1 (IFN-γ) and Th2-type cytokines (IL-4 and IL-10) indicates that bovine T-cell response during the first phases of the infestation by H. lineatum is apparently a Th0 response. 相似文献
6.
Parisi A Lanzilotta SG Addante N Normanno G Di Modugno G Dambrosio A Montagna CO 《Veterinary research communications》2007,31(1):113-123
Eleven cattle farms, 8 layer farms, 7 broiler farms and 30 broiler meat samples were investigated in south-eastern Italy throughout
2003 to evaluate the prevalence, the molecular type and antimicrobial resistance of thermophilic Campylobacters. A total of
398 samples were analysed. One Campylobacter isolate for each positive faecal swab and three isolates per positive broiler meat sample were selected for further analysis.
Multiplex PCR was performed for species-level identification and PCR-RFLP of the flagellin A gene for genotyping. Resistance
to 14 antimicrobials was studied in 188 Campylobacter isolates. Prevalence of campylobacters was high both on farms (100%) and in food samples (73%). On 4/11 cattle farms and
on 10/15 poultry farms more than one species was isolated. The presence of more than one genotype was found on 8/11 cattle
farms, on 10/15 poultry farms and in 8/22 Campylobacter-positive food samples. High rates of resistance to quinolone were observed: 9/31 (29%) C. jejuni bovine isolates, 4/22 (18%) C. jejuni poultry isolates, and 14/26 (54%) C. coli poultry isolates. Resistance to sulphamethoxazole-trimethoprim was also observed frequently: 18/26 (69%) of the avian C. coli strains, 25/31 (80%) of the C. jejuni strains isolated from poultry and 15/22 (68%) of those isolated from cattle were resistant. There was a significant difference
between the rate of resistance to macrolides of C. coli and C. jejuni isolated in poultry, which amounted to 23% and 3%, respectively. This study provided data on the prevalence and antimicrobial
resistance of thermophilic campylobacters in south-eastern Italy and confirmed that flaA-typing is an efficient tool to study the epidemiology of Campylobacter strains in short-term investigations. 相似文献
7.
Yamada S Konnai S Imamura S Simuunza M Chembensofu M Chota A Nambota A Onuma M Ohashi K 《Veterinary journal (London, England : 1997)》2009,182(2):352-355
To ascertain the infection rate for tick-borne pathogens in Zambia, an epidemiological survey of Theileria parva, Babesia bigemina and Anaplasma marginale in traditionally managed Sanga cattle was conducted using PCR. Of the 71 native Zambian cattle, 28 (39.4%) were positive for T. parva, 16 (22.5%) for B. bigemina and 34 (47.9%) for A. marginale. The mixed infection rate in cattle was 8.5% (6/71), 16.9% (12/71), 7.0% (5/71) and 2.8% (2/71) for T. parva/B. bigemina, T. parva/A. marginale, B. bigemina/A. marginale and T. parva/B. bigemina/A. marginale, respectively.To predict the risk for transmission of tick-borne pathogens from ticks to cattle, a total of 74 Rhipicephalus appendiculatus ticks were collected from a location where cattle had been found positive for T. parva. Of the ticks collected, 10 (13.5%) were found to be PCR-positive for T. parva. The results suggest that the infection rate for tick-borne pathogens was relatively high in Sanga cattle and that adult R. appendiculatus ticks were highly infected with T. parva. 相似文献
8.
Sayin F Dinçer S Karaer Z Cakmak A Inci A Yukari BA Eren H Vatansever Z Nalbantoglu S 《Tropical animal health and production》2003,35(6):521-539
An epidemiological survey for Theileria annulata infection was conducted in 12 selected villages around Ankara in Central Anatolia, Turkey, during the period April 1990 to January 1993. During the survey, 198 cattle of 30 local breeds, 84 Holstein-Friesian×local breeds and 84 Holstein-Friesian breed were examined for antibodies to T. annulata and the presence of the vector ticks. Four species of Hyalomma ticks were identified: Hyalomma anatolicum anatolicum, Hyalomma anatolicum excavtum, Hyalomma detritum and Hyalomma marginatum marginatum. Salivary gland staining indicated that infected adult ticks of all four species were present and, therefore, were implicated in the transmission of tropical theileriosis in the field. Generally, the Hyalomma infestation rate was low, with the heaviest infestations occurring on the older animals. Young adults and calves had very low infestation rates. Most ticks seen on cattle were adults, very few nymphs were found. The blood smear and serological examination of the 198 cattle conducted in March, before the start of the first disease season, showed that the prevalence of piroplasmosis was 11.1% (22 out of 198) and the seroprevalence of T. annulata was 10.6% (21 out of 198). Forty-three animals were then excluded from the study because they were seropositive and/or harboured piroplasms. Ninety-two seronegative animals showed piroplasmosis (92 out of 155) and 34 seronegative animals became seropositive for T. annulata (34 out of 155) during the three disease seasons. One animal became clinically ill with tropical theileriosis and required treatment. The incidence of cattle showing piroplasmosis and disease in the total study sample was 50.7% and 0.5% per disease season, respectively. The seroconversion rate of new infection with T. annulata in the total study was 14.3% per animal season. The number of cattle showing piroplasmosis was much greater than the number of seropositive cattle, which may indicate the presence of another species of Theileria. The two different management systems encountered in the study were considered to have influenced the tick infestation levels. 相似文献
9.
Antibodies to Hypoderma lineatum were transferred to calves via colostrum. The antibodies transferred in the colostrum demonstrated specificity to all the H. lineatum first-instar proteins which were resolved by non-denaturing polyacrylamide gel electrophoresis and were capable of mediating a Type I hypersensitivity reaction. The kinetic decline of colostrum-acquired antibodies, the effect upon development of an autologous humoral response to H. lineatum and the host or parasite protective role of these antibodies are discussed. 相似文献
10.
Hsu YM Lin CC Chomel BB Tsai KH Wu WJ Huang CG Chang CC 《Comparative immunology, microbiology and infectious diseases》2011,34(6):513-518
Rickettsia spp. are zoonotic pathogens and mainly transmitted by various arthropod vectors, such as fleas, ticks, and lice. Previous epidemiological studies indicated that ectoparasites infested on dogs or cats may be infected by Rickettsia spp., and transmit them to human beings accidentally. In this study, the prevalence of Rickettsia infection was evaluated using fleas and ticks from stray dogs and cats in Taiwan. A total of 158 pools made by 451 cat fleas (Ctenocephalides felis) from 37 dogs and 4 cats were used for analysis. Besides, 386 Rhipicephalus ticks collected from the other 62 stray dogs were included in this study. Nymphal and adult ticks were individually analyzed but larvae were separated into 21 pools for molecular detection. Partial sequencing analysis of the gltA gene was applied for Rickettsia identification. The results showed that 44.3% (70/158) of the cat flea pools were harboring Rickettsia DNA. Although 6.9% (13/187) of adult ticks were infected with Rickettsia, neither larval pools nor nymphal ticks were found to contain Rickettsia DNA. According to the results of sequencing analyses, all Rickettsia PCR-positive cat flea pools were infected with R. felis, and all Rickettsia PCR-positive adult ticks were infected with R. rhipicephali. The results of this study demonstrated that C. felis but not Rhipicephlus sanguineus (the brown dog tick) and Rh. haemaphysaloides collected from stray animals in Taiwan could be infected the zoonotic pathogen R. felis. Moreover, R. rhipicephali was only identified in adult stage of Rhipicephalus sanguineus and Rh. haemaphysaloides. 相似文献
11.
Mariana G. Spolidorio Marcelo B. Labruna Augusto M. Zago Dirlei M. Donatele Ksia M. Caliari Natalino H. Yoshinari 《Veterinary parasitology》2009,163(4):357-361
From May 2007 to March 2008, blood samples were collected from 92 healthy dogs living in 21 households (17 farms in rural area, and 4 homes in urban area) in 6 counties of the State of Espírito Santo, southeastern Brazil. In addition, ticks were collected from these dogs. A mean of 4.4 ± 3.0 dogs (range: 1–12) were sampled per household; 78 and 14 dogs were from rural and urban areas, respectively. Polymerase chain reaction (PCR) designed to amplify fragments of the 18S rDNA gene of Babesia spp or Hepatozoon spp revealed amplicons of the expected size in 20 (21.7%) dogs for Babesia, and 54 (58.7%) dogs for Hepatozoon. All Babesia-positive dogs were also Hepatozoon-positive. Among the 21 households, 15 (71.4%) from 3 counties had at least one PCR-positive dog, including 13 farms (rural area) and 2 homes (urban area). A total of 40 PCR products from the Hepatozoon-PCR, and 19 products from the Babesia-PCR were submitted to DNA sequencing. All generated sequences from Hepatozoon-PCR were identical to each other, and to corresponding 18S rDNA sequences of H. canis in GenBank. Surprisingly, all generated sequences from the Babesia PCR were also identical to corresponding 18S rDNA sequences of H. canis in GenBank. Dogs from 10 rural and 2 urban households were found infested by Rhipicephalus sanguineus ticks. Immature of Amblyomma cajennense ticks were found in dogs from only 4 rural households (also infested by R. sanguineus). All but one household with R. sanguineus-infested dogs had at least one Hepatozoon-infected dog. Statistical analysis showed that the presence of ticks (i.e. R. sanguineus) infesting dogs in the households was significantly (P < 0.05) associated with at least one PCR-positive dog. There was no significant association (P > 0.05) between PCR-positive dogs and urban or rural households. Canine hepatozoonosis caused by H. canis is a high frequent infection in Espírito Santo, Brazil, where it is possibly vectored by R. sanguineus. Since all infected dogs were found apparently healthy, the pathogenicity of H. canis for dogs in Espírito Santo is yet to be elucidated. 相似文献
12.
Prevalence and intensity of <Emphasis Type="Italic">Oestrus ovis</Emphasis> in sheep of Shiraz,southern Iran 总被引:1,自引:1,他引:0
Sardar Jafari Shoorijeh Shahram Negahban Amin Tamadon Mohammad Amin Behzadi 《Tropical animal health and production》2009,41(7):1259-1262
Two thousand and two heads obtained from slaughtered sheep at the Fars abattoirs (Shiraz, Southern Iran) between April 2006
and April 2007 were examined for the presence of Oestrus ovis larvae. Of the total heads, 995 (49.7%) were infested with O. ovis larvae. O. ovis larvae were observed in both sexes and all age groups in each season of the year. A total of 6264 larvae were collected.
The overall larval intensity for the infested sheep was 6.3, with 3.9 in spring, 5.3 in summer, 5.9 in autumn and 7.8 in winter.
Prevalence ranged from 23.3% in spring to 80% in winter. Increased infestation was observed in older animals. 相似文献
13.
朵红 《中国预防兽医学报》2012,34(8):629-631
为了解青海省藏羊感染皮蝇蛆状况及感染种类,本研究在3个地区调查了476只藏羊,对2株感染藏羊皮蝇蛆和4株感染牦牛皮蝇蛆的线粒体CO1基因种属特异性序列进行比较研究。结果表明:14只羊感染了皮蝇蛆,感染率为2.9%,总瘤胞数为27个,平均感染强度为1.9个;并扩增其长度为688 bp的序列,克隆后测序,将其序列与GenBank中的牛皮蝇、纹皮蝇蛆和中华皮蝇蛆序列进行聚类分析,结果显示青海省感染藏羊的皮蝇蛆与感染牦牛的果洛株、民和和黄南株在线粒体CO1基因片段聚类分析进化树和同源性比较中,与牛皮蝇位于同一个进化树分支上,基因片段同源性大于99%,为牛皮蝇;感染牦牛的海晏株和贵南株在线粒体CO1基因片段聚类分析进化树和同源性比较中,与中华皮蝇位于同一个进化分支上,基因片段同源性大于99%,为中华皮蝇。几个皮蝇蛆分离株种内变异率小于1%,种间变异率大于8%。 相似文献
14.
This study was carried out to determine the prevalence of cavical myiasis caused by Oestrus ovis larvae in sheep of Kars province of north-eastern part of Turkey. From 30 to 35 sheep heads (total of 387) were examined
every month regularly for O. ovis larvae during 12 months. Of 387 heads, 156 (%40.3) were infested with O. ovis larvae.. The prevalence of nasal myiasis was 54.3% in spring, 41% in summer, 28% in fall, and 38.9% in winter. The differences
among seasons were significant statistically (P < 0.05). Infestation rate up to 1-years-old was 30.0%, 1 to 3 years-old 40.0%
and older than 3 years old was 52.4%. The number of larvae made peak in spring months and went down in the months of fall.
The mean number of larvae regarding examined animals was 1.8, and the mean according to infested animals was 4.5. Density
of O.ovis larvae in infested sheep were changed from 1 to 31. Infestation rate in the morkaraman breed was higher (43.4%) comparing
to the rate in the akkaraman breed (31.3%). The differences between sheep breed were also significant (p < 0.05). Sheep with
dark colored head had higher infestation rate than that of sheep with light colored head (p < 0.05). 相似文献
15.
埃普利诺菌素浇泼剂对牦牛皮蝇幼虫驱除效果试验 总被引:3,自引:0,他引:3
应用埃普利诺菌素浇泼剂驱除牦牛皮蝇幼虫,并设埃普利诺菌素注射剂药物对照组和阳性对照组。结果:剖检埃普利诺菌素浇泼剂300μg/kg,400μg/kg,500μg/kg剂量组牦牛与药物对照埃普利诺菌素注射剂组及伊维菌素浇泼剂组牦牛,均未检出皮蝇1期幼虫,而阳性对照组牦牛皮蝇1期幼虫感染率35.0%,平均感染强度29.4(9~53)条。翌年3、5月份两次触摸检查牛背部皮下瘤疤和皮肤虫孔,4个药物试验组牦牛均未检出,而阳性对照组牦牛两次检查平均感染率45.16%,平均感染强度6.45个。试验证明埃普利诺菌素浇泼剂低、中、高3个剂量对寄生于牦牛的皮蝇幼虫驱净率、驱虫率均达100.0%,高效安全。 相似文献
16.
A chemoprophylactic field trial was conducted to assess the efficacy of pour-on eprinomectin applied at the approximate dose of 50 mcg/kg to dairy cattle with naturally occurring hypodermosis. Two-hundred-eleven cattle, selected from two herds with a high prevalence of Hypoderma spp. infestation, were divided in three groups: Group A (N = 71) was treated with pour-on eprinomectin at the recommended dosage of 500 mcg/kg, Group B (N = 64) at the lower dose of 50 mcg/kg, a third group (Group C, N = 76) served as untreated control group. Treatments were performed in November-December 2002 and the animals were examined for the presence of warbles in the following April and June. No larvae emerged in the treated groups, whereas a variable number of warbles (ranging from 1 to 28) were found in control animals. Adverse reactions were not observed in any animal, and only minor side effects were observed. A larger field trial carried out in the following year (1064 treated and 131 untreated control cattle) confirmed the chemoprophylactic efficacy of minidosed eprinomectin against Hypoderma spp. Administration of eprinomectin minidoses in dairy cattle is interesting because of the low costs involved and no need for milk withdrawal. 相似文献
17.
R. Hennings 《Veterinary parasitology》1977,3(3):211-216
For decades, about 30% of the young cattle in the Steinfurt district of the North German Basin were infested with Hypoderma bovis. Compulsory treatment with rotenone between 1934 and 1963 failed to control infestation. When systemic organophosphorous insecticides became available a 3-year scheme was instituted in which all the 6–24-month-old cattle were treated annually, between 15 November and 15 December, with trichlorfon spot-on.At first, the treatment was not compulsory and warble infestation was occasionally found in cattle purchased outside the district. Later, the treatment was made compulsory and since 1966 warble infestation has not been detected in the district. 相似文献
18.
Beata Mal
ekov Monika Halnov Zlatana Sulínov Ladislav Molnr Petra Ravaszov Jozef Adam Milo Haln Igor Valocký Milan Baranovi
《Research in veterinary science》2010,89(3):358-361
The presence of antibodies against Encephalitozoon cuniculi (E. cuniculi) and Encephalitozoon intestinalis (E. intestinalis) was examined in 215 samples from humans and in 488 samples from five different species of domestic and companion animals in Slovakia. The 215 human samples and samples from 90 swine, 123 non-infected cattle (cattle), 24 cattle infected with bovine leukosis virus (BLV-positive cattle), 140 sheep and 111 dogs were examined by the enzyme-linked immunosorbent assay (ELISA). Samples with serum titres 1:200 or higher were considered as positive. Specific anti-E. cuniculi antibodies were found in humans (0.9%), swine (52%), cattle (2%), sheep (9%) and dogs (15%) except for the BLV-positive cattle at the titre of 1:200. The titre of 1:400 was detected only in humans (0.5%). The presence of specific anti-E. intestinalis antibodies at the titre of 1:200 was confirmed in humans (6%), swine (51%), cattle (11%), BLV-positive cattle (13%) and dogs (6%) but not in sheep. The anti-E. intestinalis antibodies reached the 1:400 in humans (1%), swine (4%) and BLV-positive cattle (17%). The presence of specific anti-E. intestinalis antibodies at the titre of 1:600 was observed only in one swine (1%). Significant differences were observed in animals at titres 1:200 and 1:400 (chi-squared test: p < 0.0001) for both pathogens and in humans only for E. cuniculi at the titre of 1:400 (chi-squared test: p < 0.0075). 相似文献
19.
Zalmen Henkin Avi Perevolotsky Arik Rosenfeld Arieh Brosh Fred Provenza Nissim Silanikove 《Livestock Science》2009,126(1-3):245-251
The aim of the present study was to determine the effect of polyethylene glycol (PEG) supplementation on grazing behaviour of beef cattle and on utilization of the woody components of a Mediterranean shrubland. Two experiments were conducted on two different sites in Northern Israel, Ramat Hanadiv (RH) and Hatal. On each site, the study area was divided into two paddocks, in one cattle were supplemented with 50 g PEG day− 1 per cow, while the other served as a control, with no PEG supplementation. In RH site the cows had free access to Prolix and in Hatal to poultry litter, both serving as a nitrogen supplement during the experiment. In the RH site, the consumption of Pistacia lentiscus, a shrub whose leaves contain high concentration of tannins, was found higher (P = 0.001) in the PEG group diet than in the control group. In Hatal site PEG increased foraging time by 18%, daily foraging distance by 15% and reduced the use of supplementary feed (poultry litter) by 20%. However, PEG did not affect the average cow body weight or water consumption on either site. It is concluded that PEG influences grazing behaviour of beef cattle on shrubby rangeland and increases the use of woody species with high tannin concentrations. 相似文献
20.
M.A. Khan 《Veterinary parasitology》1977,3(3):217-223
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. 相似文献