Risk factors for Psoroptes ovis mange on Belgian Blue farms in Northern Belgium

Sarre, Charlotte; Bleecker, Koen De; Deprez, Piet; Levecke, Bruno; Charlier, Johannes; Vercruysse, Jozef; Claerebout, Edwin

doi:10.1016/j.vetpar.2012.05.026

Cited by 17 publications

(25 citation statements)

References 14 publications

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“…Although treatment failure can often be attributed to non-compliance with recommended treatment and control measures [18], resistance of P. ovis populations against ML is suspected [19][20][21] and could be the result of decades of frequent and indiscriminate use of ML.…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, even if the WAAVP efficacy guidelines for acaricide efficacy would have been followed, ML efficacy would only be sufficient on 5 out of 16 farms (MC reduction > 90%), which supports our conclusion that ML resistance is widespread in BB farms in northern Belgium and the south of The Netherlands. The presence of ML resistance in Belgium is no surprise, since suboptimal treatments have been applied by the majority of Belgian beef farmers for some time [18]. The emergence of ML resistance in P. ovis in beef farms in different countries (Argentina, Belgium, The Netherlands) is worrying and needs further investigation.…”

Section: Discussionmentioning

confidence: 99%

“…Suboptimal treatment cannot be ruled out in the studies mentioned above, as either a long treatment interval (14 days) was used [16] or not all animals were treated in every treatment round [3]. Sarre et al [18] mentioned that less than half of the Belgian farmers applied correct treatment against Psoroptes. Commonly made mistakes include underdosing, a single treatment, a long treatment interval, the use of a suboptimal drug formulation or a lack of additional control measures, e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Commonly made mistakes include underdosing, a single treatment, a long treatment interval, the use of a suboptimal drug formulation or a lack of additional control measures, e.g. not shearing of the animals or partial treatment of the herd [18]. Recently, decreased in vitro susceptibility to ML was seen in mites collected from sheep farms with reported treatment failure [19,20].…”

Section: Introductionmentioning

confidence: 99%

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Resistance against macrocyclic lactones in Psoroptes ovis in cattle

Mol

Wilde

Casaert

et al. 2019

Preprint

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BackgroundPsoroptic mange is an important disease in beef cattle, and Belgian Blue cattle are particularly susceptible. Treatment failure of macrocyclic lactones against Psoroptes ovis has been reported, but clear evidence of in vivo resistance is still lacking. This study was conducted to investigate ML efficacy in 16 beef farms in Belgium and The Netherlands in vivo and in vitro. MethodsOn each farm a group of animals (n= 7-14) with clinical psoroptic mange was treated with two subcutaneous injections of a macrocyclic lactone with 7-10 days interval (15 farms) or a single injection with a long-acting macrocyclic lactone (1 farm). In vivo efficacy was assessed by the reduction in mite counts and clinical index (part of the body affected by lesions), the cure rate after the first treatment round and the number of treatment rounds needed to cure all animals. In vitro knock-down and mortality was evaluated in a contact test. ResultsCure rates after the first treatment round varied from 0-80%. All farms needed two or more rounds of treatments to obtain full efficacy. Clinical index had a high variation and only started to reduce after the second treatment round. Only three farms were categorized as susceptible with a mean mite count reduction>95% and a lower limit of the uncertainty interval>90%. One farm had a mean reduction>95%, but its lower limit of the confidence interval was <90%. All other farms had mean reductions<95% and lower limits of their uncertainty intervals<90%. No correlation was found between in vitro lethal dose 50 and knock-down dose 50 values and any parameter of in vivo efficacy. ConclusionUnambiguous treatment failure was detected on 12/16 beef farms, confirming the presence of macrocyclic lactone resistance in Belgian Blue beef farms. In vitro parameters could not discriminate the farms based on their in vivo susceptibility. The mean reduction in mite counts and the lower limit of the confidence interval stood out as most useful parameter to identify acaricide resistance.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Resistance against macrocyclic lactones in Psoroptes ovis in cattle

Mol

Wilde

Casaert

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Suboptimal treatment cannot be ruled out in the studies mentioned above, as either a long treatment interval (14 days) was used [13] or not all animals were treated in every treatment round [3]. Sarre et al [15] mentioned that less than half of the Belgian farmers applied correct treatment against Psoroptes. Commonly made mistakes include underdosing, a single treatment, a long treatment interval, the use of a suboptimal drug formulation or a lack of additional control measures, e.g.…”

Section: Introductionmentioning

confidence: 99%

Resistance against macrocyclic lactones in Psoroptes ovis in cattle

et al. 2020

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Background: Psoroptic mange is an important disease in Belgian Blue cattle. Treatment failure of macrocyclic lactones against Psoroptes ovis has been reported, but clear evidence of in vivo resistance is lacking. This study assessed the efficacy of macrocyclic lactone products on 16 beef farms in Belgium and the Netherlands in vivo and in vitro. Methods:On each farm a group of animals (n = 7-14) with psoroptic mange was treated with two subcutaneous injections of a macrocyclic lactone product with 7-10 days interval (15 farms) or a single injection with a long-acting macrocyclic lactone (1 farm). In vivo efficacy was assessed by the reduction in mite counts, clinical index (proportion of the body surface affected by lesions), the proportion of the animals with negative mite counts after the first treatment round and the number of treatment rounds needed to obtain zero mites counts in all animals. A mite population was categorized as sensitive when the mite count reduction after the first treatment round > 95% and the lower limit of the uncertainty interval > 90%. Resistance was detected when both parameters were below their threshold and suspected when one parameter was too low. In vitro knockdown and mortality were evaluated in a contact test. Results:The proportion of the animals with negative mite counts after the first treatment round varied from 0 to 80%. All farms needed two or more treatments rounds to obtain zero mite counts on all animals. Clinical index only started to reduce after the second treatment round. Mite populations from three farms were categorized as sensitive, one as suspected resistant and 12 as resistant. No correlation was found between in vitro lethal dose 50 and knockdown dose 50 values and in vivo efficacy parameters. Conclusions:Unambiguous treatment failure was detected on 12 out of 16 farms, confirming the presence of macrocyclic lactone resistance on Belgian Blue beef farms. In vitro parameters could not discriminate the farms based on their in vivo sensitivity. The mean reduction in mite counts and the lower limit of the confidence interval are proposed as parameters to identify acaricide resistance.

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Treatment and control of bovine sarcoptic and psoroptic mange infestation with ivermectin long-acting injectable (IVOMEC® GOLD)

Hamel¹,

Joachim

Löwenstein

et al. 2014

Parasitol Res

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The efficacy of ivermectin long-acting injection (IVM LAI, IVOMEC® GOLD, Merial; 3.15 % ivermectin w/v) formulation was evaluated in cattle with induced Sarcoptes scabiei var. bovis or Psoroptes ovis infestations. A total of 64 cattle were included in this series of four studies, with 16 animals per study. Approximately, 8 weeks following initial induced mite infestation, cattle were allocated to treatment groups based on decreasing pre-treatment bodyweights. Treatments (saline (control) or IVM LAI (630 mcg ivermectin/kg bodyweight) at 1 mL/50 kg bodyweight) were administered by a single subcutaneous injection in front of the right shoulder on Day 0. Skin scrapings were collected prior to treatment and at approximately weekly intervals for 8 weeks thereafter to establish live mite counts. Character and extent of skin lesions were evaluated at each sampling. Animals were weighed before treatment and at the end of the studies. Mite counts of the IVM LAI-treated animals were significantly (p < 0.05) lower than those of the controls in all four studies at all occasions post-treatment. In the two Sarcoptes studies, IVM LAI-treated cattle were free of mites at 14 days after treatment and in the Psoroptes studies at 13 or 28 days post-treatment. All IVM LAI-treated cattle remained free of mites to the end of the studies while all control animals remained infested. Mange lesions of the IVM LAI-treated animals improved significantly (p < 0.05) compared to those of the controls from Day 21 (Sarcoptes studies) and from Days 28 or 34 (Psoroptes studies). In all studies, mean weight gain over the 8 week post-treatment period was significantly (p < 0.05) higher for the IVM LAI-treated animals than for the controls: Sarcoptes studies, 64.1 and 68.6 kg vs. 46.9 and 48.6 kg, respectively; Psoroptes studies, 43.0 and 43.4 kg vs. 20.8 and 34.9 kg, respectively. All animals accepted the treatment well, and no treatment-related health problems and adverse events were observed throughout the studies. These studies demonstrated the high efficacy of IVOMEC® GOLD against sarcoptic and psoroptic mange in cattle.

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Risk factors for Psoroptes ovis mange on Belgian Blue farms in Northern Belgium

Cited by 17 publications

References 14 publications

Resistance against macrocyclic lactones in Psoroptes ovis in cattle

Resistance against macrocyclic lactones in Psoroptes ovis in cattle

Resistance against macrocyclic lactones in Psoroptes ovis in cattle

Treatment and control of bovine sarcoptic and psoroptic mange infestation with ivermectin long-acting injectable (IVOMEC® GOLD)

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