Psoroptes Research Articles

Making the best use of existing tools and treatments for the long-term, sustainable control of sheep

Sheep scab, caused by the ectoparasitic mite Psoroptes ovis, significantly affects the UK sheep industry, with annual costs estimated between £80–200 million. Despite previous eradication efforts, sheep scab persists with an estimated 8–10k outbreaks annually. Treatment is limited to macrocyclic lactone (ML) injectables and organophosphate (OP) plunge dipping, with the emergence of ML-resistant mites highlighting the importance of OP dipping and the need to use the MLs both strategically and responsibly in the future. Diagnostic advancements, including a sheep scab ELISA blood test, enable early detection and targeted treatment. Recent control projects have demonstrated the potential for coordinated control to manage and reduce sheep scab incidence.

A novel cystatin in Psoroptes ovis var. cuniculi: molecular characterization, serodiagnostic potential, and its anti-inflammatory property on rabbit peripheral blood mononuclear cells

BackgroundThe ectoparasite Psoroptes ovis var. cuniculi causes substantial economic losses to the global rabbit industry. Currently, microscopy for identifying Psoroptes mite in skin scrapings, as the “diagnosis gold standard,” remains a challenge owing to its poor sensitivity in detecting low-level and/or early stage mite infestations. Additionally, Psoroptes infestations rapidly trigger cutaneous inflammation, thus the mites might produce some molecules to deal with the harmful effects of inflammation for their long-time survival on the host skin, but these molecules are still mostly unknown.MethodsTo seek a sensitive diagnostic method and illuminate the new antiinflammatory molecules, we characterized a novel cystatin of P. ovis var. cuniculi (PsoCys) using bioinformatics and molecular biology methods.ResultsThe results showed that PsoCys comprised the classical features of the type II cystatin superfamily including an N-terminal glycine residue, a central QXVXG motif, and a C-terminal LW motif. In mixed stages of mites, the transcription level of PsoCys was significantly higher in “fed” mites than in “starved” mites (P < 0.001), and among the different life-cycle stages of “fed” mites, the expression of PsoCys was higher in adult males than in larva, nymph, and adult females (P < 0.001). The established indirect ELISA based on recombinant PsoCys (rPsoCys-iELISA) presented 95.4% sensitivity and 95.7% specificity. The area under the receiver operating characteristic curve (AUC) for this method was 0.991, indicating its excellent diagnostic performance. Moreover, rPsoCys-iELISA had advantages over microscopy for detecting low-level and/or early stage mite infestations (90% versus 40% in artificial infestation cases at 3 weeks post-infestation; 61.9% versus 22.6% in clinical cases). In addition, rPsoCys could inhibit the activity of papain and cathepsin B in vitro, and significantly suppressed mRNA levels of toll-like receptors (TLR 1, 2, 4, and 6) and downstream molecules (NF-κB, p38, MyD88, IL-10, and IFN-γ) in LPS-stimulated rabbit PBMCs, indicating its anti-inflammatory property.ConclusionsOur findings indicated that PsoCys was a novel type II cystatin of Psoroptes mites, and it served as a potential serological diagnostic antigen for detecting low-level and/or early stage mite infestations, as well as a novel anti-inflammatory molecule of Psoroptes mites.Graphical abstract

Efficacy of antiparasitic macrocyclic lactone drops against passalurosis and psoroptic mange in rabbits

The purpose of the research is to study the efficacy of a macrocyclic lactone drug using the spot-on method against passalurosis and psoroptic mange in rabbits.Materials and methods. The study was conducted at the Department of Parasitology and Veterinary-Sanitary Expertise of the MVA named after K. I. Skryabin in 2022–2023 to determine the efficacy of antiparasitic drops (active ingredients: phenylpyrazole derivative, pyrazinoisoquinoline derivative, macrocyclic lactone, insect growth regulator, manufactured by AVZ S-P, LLC) against passalurosis and psoroptic mange. The antiparasitic drops were applied by the spot-on method to rabbits of different age and sex groups in doses of 0.5 mL per animal for body weight of up to 4 kg and 1 mL per animal for body weight of 4 to 8 kg against passalurosis and psoroptic mange. Rabbit fecal samples were examined using the Fülleborn method. Skin scrapings from the inner auricle surface were studied for Psoroptes cuniculi mites as per D. A. Priselkova.Results and discussion. The antiparasitic drug was found to have 100 % efficacy against ticks Psoroptes cuniculi and nematodes Passalurus ambigus.

First report on the occurrence of psoroptic mange in llamas (Lama glama) of the Andean region.

An outbreak of Psoroptes sp.-caused mange was detected in a llama herd of Larcas, Jujuy province, Argentina. Infested llamas showed alopecia, erythema, hyperpigmentation, hyperkeratosis, and inflammation of the ear pinnae, as well as crusts and serous, serosanguineous, or purulent drainage with unpleasant smell in the external ear canal. Microscopic evaluation of skin scrapings revealed 0.5- to 0.7-mm-long acari identified as Psoroptes sp. based on their morphology. Histology showed a typical allergic reaction with perivascular to periadnexal mixed inflammatory infiltrate. Phylogenetic tree analysis showed that the cytochrome c oxidase subunit I gene sequences analyzed from the sampled acari clustered into a single P. ovis clade including sequences isolated from rabbits and bighorn sheep, with P. natalensis as a sister taxon that infested bighorn sheep from the USA. Phylogenetic analysis of cytochrome b sequences showed three well-supported clades, one of which contained the sequences of the Larcas llamas and US bighorn sheep isolates. This is the first report on P. ovis infestation of llamas raised in their original location. Investigations on mange etiological agents acting on South American camelids and their distribution are necessary to implement control strategies to mitigate the negative impacts of these parasitic infections.

Effect of infestation with Psoroptes cuniculi on reproduction and behavior of obese rabbit does (Oryctolagus cuniculi).

Parasites and obesity are health problems worldwide. Rabbits are production animals yielding one of the healthiest meats, also taking advantage of skin, hair, limbs and excreta. It is among the most frequent pets in some countries and widely used as animal model in research. Psoroptes cuniculi is a mite of high transmission rate, affecting welfare and production and obesity causes multiple metabolic, endocrine and immunological disorders, being an emerging problem in domestic animals. Obesity and acarosis are prolonged stressors, modifying the activity of the hypothalamic-pituitary-adrenal axis that can induce metabolic and behavioral disorders. Alterations caused by comorbidities could be similar to or different from those induced by each morbidity separately. We analyzed the influence of obesity on the infection degree with P. cuniculi and on behavior and production. Rabbit does induced to obesity were infected and mated; behaviors in the open field test, obesity estimation indices and productive parameters at delivery and weaning were analyzed. The acarosis induced a decrease in feed intake and a decrease in body weight, a decrease in locomotor, exploratory and chinning behaviors in normal weight and obese does. The infection induced 23% mortality at birth, obesity 45% and comorbidity 74%, while in normal weight rabbits a 6.5% was observed. Weight gain from birth to weaning was lower in the comorbid group, reaching a litter weight of 4.5±0.13 kg in healthy normal weight does and 2.6±0.67 kg in comorbid does. The disturbances induced by the comorbidity were magnified in both behavioral and productive parameters.

Haematobiochemical Alterations in Rabbit Mange

Mange in rabbits is an economically important parasitic disease which cause significant loss in productivity, body weight and fur quality. Forty eight rabbits with clinical signs of alopecia, anorexia, pruritis, skin erosions and dry crust like lesions on extremities, ears, nose and face were brought to Veterinary Clinical Complex, Rajendranagar and Hyderabad. Skin scrapings were collected, processed and examined under microscope to detect mite infestation. Different mites i.e. Sarcoptes scabiei, Psoroptes cuniculi, Notoedres cuniculi, Demodex cuniculi and Cheyletiella parasitivorax were noticed in rabbits. Haematological examination revealed a significant (p&lt;0.05) decrease in haemoglobin, PCV, RBC count and a significant (p&lt;0.05) increase in TLC count in affected rabbits. Serum analysis showed a significant (p&lt;0.05) increase in ALT and AST levels in infected rabbits. Treatment with ivermectin along with proper management resulted in recovery from mange in rabbits.

Genetic and genomic analysis of Belgian Blue’s susceptibility for psoroptic mange

BackgroundPsoroptic mange, caused by Psoroptes ovis mites, is affecting Belgian Blue cattle’s welfare and production potential. The Belgian Blue cattle—known for its high degree of muscling, low feed conversion ratio and high beef quality—is highly susceptible for this disease.ResultsIn this study, we phenotyped 1975 Belgian Blue cattle from more than 100 different groups on commercial beef farms for their psoroptic mange susceptibility. Substantial individual differences were observed within these management groups, with lesion extent differences up to ± 15%. Animal models showed that estimated heritabilities were low for lesion extent and severe lesion extent (0.07 and 0.09, respectively) and 0.12 for the number of mites. A genome wide association study for mange susceptibility revealed signals on BTA6, BTA11, BTA15 and BTA24. In these regions, candidate genes GBA3, RAG2, and TRAF6 were identified.ConclusionsDespite the challenges in phenotyping for psoroptic mange due to the timing of screening, the continuous evolution of lesions and different management conditions, we successfully conducted a study on the genetic susceptibility to psoroptic mange in Belgian Blue cattle. Our results clearly indicate that psoroptic mange is under polygenic control and the underlying candidate genes should be studied more thoroughly. This is the first study providing candidate genes for this complex disease. These results are already valuable for Belgian Blue breeding, however, further research is needed to unravel the architecture of this disease and to identify causal mutations.

Prevalence and clinico-pathology of PSOROPTIC mange in buffaloes of the Amazon region

Scabies is an important skin disease in several species of domestic and wild animals; however, few reports in Brazil have emphasized its occurrence in buffaloes. This article describes the epidemiological, clinical and pathological aspects and diagnosis of psoroptic mange in buffaloes in a property in the municipality of Castanhal, PA, Amazon region. Of the 41 buffaloes examined, 38 males and females of the Murrah, Baio, Mediterranean and Carabao breeds and their crossbreeds, aged between 2 and 20 years, had a history of pruritus. Clinical examination was performed to map the lesions, skin scrapings were collected to identify the mites, and a biopsy was performed for histopathological examination. Clinical signs, from mild to severe intensity, varied according to the system of creation and handling of the animals and were more severe in buffaloes raised in bays than those raised under a collective regime (pastures and collective troughs). The characteristic clinical signs were intense itching, extensive areas of alopecia, periocular edema, and thickening of the epidermis with exudative crusts covering the face, chamfer, neck, scapular region, back, base of the horn, thoracic and pelvic limbs and chest. The behavior of rubbing the affected regions of the body against structures (troughs, fence posts, gates) or with the horns was frequently observed and provided relief from itching. In the most severe cases, mites were also noted in the crusts, which were identified as Psoroptes natalensis. Histological skin lesions exhibited alterations consistent with immune-mediated dermatitis, which is typical of hypersensitivity to mite-derived allergens.

Hotspot sheep scab management: A community-based regional approach in England.

Ovine psoroptic mange (sheep scab), caused by an infestation of the mite Psoroptes ovis, leads to clinical disease, economic loss and severely compromised animal welfare. Here, a community-based approach to the management of scab in three high-risk areas of England is described. For each of the 254 farms included in the study, an initial survey of their clinical sheep scab history was followed up by a blood test (ELISA) to detect the presence of antibodies to P. ovis. This facilitated the coordination of treatment across groups of farms in each region. Blood testing was then repeated at the end of the treatment programme. On the first blood test in 2021/2022, 25.6% (±5.5%) of the flocks were positive for sheep scab. On the second test in 2022/2023, 9% (±3.94%) of the flocks tested were positive, showing a highly statistically significant reduction in prevalence overall,but with strong regional variation. generating an understanding of the flock-level nature of the blood test and confidence in its detection of scab where clinical signs were not apparent provided ongoing challenges. The programme demonstrated that a focused community-based approach can be used to significantly reduce the prevalence of sheep scab in high-risk areas of England. The use of the blood test on all farms allowed the identification of subclinical sheep scab. The programme provides an effective model for sheep scab management on a national scale.

The tales of contradiction: A thematic analysis of British sheep farmers’ perceptions of managing sheep scab in their flocks

Sheep scab is endemic in Great Britain with an estimated national herd-level prevalence of 10.9% from a surveyed population of sheep farms. Previous studies have investigated how sheep farmers manage sheep scab on their farms in Great Britain, but there have not been any qualitative studies investigating sheep farmers perceptions on the roles different stakeholders have in the management of sheep scab. This qualitative study aims to explore how sheep farmers perceive their role and the different stakeholders’ roles in the management of sheep scab, and how they would like sheep scab to be managed going forward. Semi-structured interviews were conducted with 43 sheep farmers from England, Scotland, and Wales. The data were analysed using reflexive thematic analysis, through the theoretical lens of Foucault’s notion of ‘biopower’. Two themes were generated: ‘The feeling of powerlessness leads to a need of rules and regulations’, with sub-themes: ‘The need for governmental rules and regulations’ and ‘The need for rules and regulation at livestock markets’, and ‘An apparent lack of sheep scab surveillance’, with sub-themes: ‘The farmers perceive that the veterinarians have control over surveillance’ and ‘The farmers have control over surveillance on their farms’. In the first theme, the respondents suggested that more rules and regulations to control the management of sheep scab was required. This included reinstating of sheep scab as a notifiable disease in England and Wales, as well as more regulations at livestock markets to prevent the trading of infested sheep; both of which would subject the farmers to regulatory power mechanisms. The second theme centred around who has the control of surveillance on the farms. Most of the respondents perceived that the veterinarians had knowledge and expertise of the local area on sheep scab, which they were able to relay to the farmers. Thus, veterinarians exerted disciplinary power by creating ‘docile’ bodies. However, it also appeared that veterinarians were not regularly called onto farms. Although disciplinary power flows through the interactions between the farmer and veterinarian, the techniques currently used are not always having their desired effect. The study demonstrated that how sheep farmers want sheep scab to be managed is, at times, conflicting and contradictory, which highlights the complexity of sheep scab as a disease to manage.

Psoroptes cuniculi infestation in pet rabbits in Tabasco, Mexico, 2021-2022.

Rabbits are an important worldwide meat- and fibre-producing animal, and they are popular pets. The rabbit ear mite, Psoroptes cuniculi, causes severe dermatological disease. Epidemiological data on P. cuniculi infestations are important for public health. The objective of the study was to determine the frequency of P. cuniculi infestation in pet rabbits and evaluate epidemiological factors associated with infestation. Two hundred pet rabbits presented for veterinary care between 2021 and 2022. Physical examination, otoscopy and microscopy were used for ear mite identification. Association with age, sex, body mass index (BMI), breed, feeding and housing management was analysed. Of the 200 rabbits, 59 (29.5%) were positive for P. cuniculi. Only female sex had a positive association with P. cuniculi. Psoroptes cuniculi in pet rabbits has a similar frequency to that reported in meat-producing rabbits, and female sex had a positive association.

Incidence of Mange Infestation in Rabbits

Background: Farmers raise rabbits in abundance in Iraq. Scabies infestation is one of the most prevalent diseases in rabbits. The current study investigates the rabbits’ infestation with scabies that cause severe complications such as itchy alopecia, hyperkeratosis, anorexia, self-trauma, and weight loss. In short, the disease has high morbidity and mortality and creates heavy economic losses for farmers. Objectives: This study was designed to detect mange infestation in rabbits using microscopic examination of skin scraping. This study is the first to investigate mange infestation in rabbits in Mosul City, Iraq. Methods: A total of 130 rabbits were examined, and their skin lesions were scraped. Results: Of 130 rabbits, 56(43.1%) were infested with mange, including Sarcoptes scabiei var. cuniculi (n=50, 38.5%), Psoroptes cuniculi (n=32, 25%), Notoedres cati var. cuniculi (n=26, 20%), Demodex cuniculi (n=12, 9%), and Cheyletiella spp. (n=4, 3%), with the high infestation rate for S. scabiei var. cuniculi and the lowest rate for Cheyletiella spp. The significant lesions were hyperkeratosis followed by alopecia, then pruritus on many body areas (head, ears, abdomen, back, legs, tail, and perineal area). The highest infestation rate was found on the abdomen and back, while the lowest was on the tail and perineal area. There are significant differences according to age, while no significant differences between the males and females and among three types of infestation (single, double, and mixed). Conclusion: The rabbits were infested with several species with different percentages. There was no significant difference in infestation rates between males and females, although there was a difference between younger and older animals. Lastly, a significant difference was clear among the three types of infestation, and the double one was the dominant infestation rate with 50%.

Is Chorioptes texanus to Displace Chorioptes bovis? Notes on the Mites Causing Bovine Chorioptic Mange in Central Europe

Chorioptic mange is the most common type of bovine mange in central Europe, affecting mainly housed dairy cattle. Until 1976, when Chorioptes texanus were described for the first time from mangy cattle in Brazil, bovine chorioptic mange was thought to be caused only by C. bovis mites. In Europe, C. texanus parasitism in cattle was for the first time reported in Germany in 1998. Following the repeated diagnosis of C. texanus mites in skin scrapings from local cattle in recent years, scrapings from cattle that were clinically suspicious for chorioptic mange were requested and provided during the years from 2019 to 2022 from Austria, France, Germany, and Switzerland (from 6, 17, 28, and 7 farms, respectively) and from dairy cows of 1 farm in Canada. Mites were isolated from the scrapings, cleared, and microscopically identified based on their morphology. Examination of scrapings revealed the presence of C. texanus in the cattle from 2 farms in Austria, 13 farms in France, 7 farms in Germany, 1 farm in Switzerland, and in the specimens from Canada. Chorioptes bovis mites were recovered only in scrapings from 5 farms in Germany and Psoroptes ovis mites in scrapings of cattle from 2 farms in France. The scrapings did not reveal co-infestations of C. bovis and C. texanus or of Chorioptes species and P. ovis. The records of C. texanus from Austria, France, Switzerland, and Canada constitute the first descriptions of this mite species in these countries. Although this investigation was based on an opportunistic collection of the material and was of small extent, the results suggest a widespread occurrence of C. texanus in central Europe and may emphasize the need for studies to closely investigate the nature of the causative agents of chorioptic mange in cattle and other hosts.

Behavioural Factors Influencing the Intention to Adopt Sheep Scab Control Measures in Northern Ireland.

Sheep scab, caused by infestation with the ectoparasitic mite Psoroptes ovis, is an endemic disease in the Northern Ireland (NI) sheep flock and constitutes significant economic and welfare burdens for the NI farming industry. Despite its endemic nature, historically, little research has been undertaken to support the control of the disease in NI. This study offers the first attempt to analyse the psychological and behavioural factors influencing farmers' intentions to implement effective sheep scab control measures in NI. To achieve our objective, quantitative data from a sample of 126 sheep farmers were statistically analysed using an extended theory of planned behaviour approach in an ordered logistic regression modelling framework. Our analyses showed that sheep scab remains an issue of concern in Northern Ireland. The attitudes of the farmers, as well as perceived behavioural control, emotional effect, membership of Business Development Groups (BDGs), and higher education qualifications, were found to be statistically significant factors influencing farmers' intentions to adopt sheep scab control measures. This study provides a solid foundation for how to promote behavioural changes among sheep farmers to improve their ability to implement effective disease control measures, helping to tackle this challenging disease in a more sustainable way in the future.

Repeated Cross-Sectional Survey of Ectoparasites in Sheep from Central Tunisia: Does Low Prevalence Indicate Good Hygiene or Resistance to Ectoparasites?

Sheep ectoparasites such as chewing lice, fleas and ticks are serious constraints to sheep productivity and are the cause of skin lesions in animals that decrease their market value. This study aims at investigating the ectoparasite fauna infesting small ruminants in the district of Sidi Bouzid (central Tunisia). A total of 1243 Barbarine and Queue Fine de l'Ouest (QFO) sheep were examined every two months for one year. Of the total animals examined, 74 were infested by at least 1 parasite group (5.95%). Three ectoparasite groups were identified as Psoroptes ovis (0.48%; 6/1243), ticks (5.3%; n = 66/1243) and one specimen of Ctenocephalides canis (0.08%; n = 1/1243). The most abundant tick among the 358 specimens was Rhipicephalus sanguineus sensu lato (n = 337; 94.1%), followed by Hyalomma impeltatum (n = 7/358; 1.9%), H. dromedarii (n = 7/358; 1.9%), H. excavatum (n = 5/358; 1.4%) and only two specimens of H. scupense (n = 2/358; 0.55%). The sheep herds showed low infestation prevalence by ectoparasite over the year, with a significant difference according to the seasons (p < 0.05). A higher infestation prevalence was recorded in March (14.36%). Barbarine sheep breed showed significantly higher infestation prevalence (16.8%) compared to QFO (0.8%) (p < 0.01). There were no differences in infestation prevalence according to sex of the animal or age groups. Knowledge of the ectoparasite population harboured by sheep, its activity dynamics and risk factors is required to develop effective ectoparasite control options. The low prevalence of ectoparasite infestation in sheep reported here may be due to possible genetic resistance or simply to successful hygiene measures implemented by farmers.

Livestock Workshops: eradication of disease

In this online workshop Dr Neil Paton, Lecturer in Farm Animal Health and Production at the Royal Veterinary College and Technical Director of the Gwaredu BVD and Gwaredu Sacb programmes, discussed the eradication of disease on farm, with a focus on bovine viral diarrhoea and sheep scab.

Assessment of knowledge, attitudes, and practices related to the prevalence of sheep scab among communal sheep farmers in Eastern Cape Province, South Africa

Background and Aim: Sheep scab is one of the most contagious diseases of sheep found in rural communities worldwide and is a major health and welfare concern for sheep farming. Information on the attitudes of communal farmers to sheep scab remains speculative in the Eastern Cape Province. This study aimed to investigate knowledge, attitudes, and practices related to the prevalence of sheep scab among communal sheep farmers in Eastern Cape Province, South Africa. Materials and Methods: From June to August 2022, a cross-sectional survey using a semi-structured questionnaire (n = 160) was conducted in two rural communities of the Enoch Mgijima Local Municipality in Eastern Cape Province. Purpose sampling was used to obtain respondents’ knowledge, attitudes, and management practices regarding sheep scabs. Results: Among respondents, 81% were males and 19% were females. The majority of sheep farmers (59%) in both communities were aware of sheep scabs, but the majority (64%) did not receive any farming training. The majority of sheep farmers (65%) believed that sheep scab was the most serious threat to their sheep production since it increased mortality. In the past 3 years, approximately 57% of respondents reported an increase in the prevalence of sheep scab. The majority of farmers reported wool loss as the most noticeable clinical symptom (73%). More than 80% of sheep farmers do not use acaricide on a regular basis. Sixty-one percent of farmers prefer a pour-on topical application method. The frequency of annual dipping was every fortnight (40%), during summer and winter (24%). Most farmers (66%) regularly vaccinate their sheep. Conclusion: The prevalence of sheep scab is increasing in these communities; however, a better understanding of the factors that facilitate its transmission is required to allow improved management and control of this disease. The government must involve extension officers and distribute them to disseminate information to farmers. Thus, it will be easy to translate the literature into action. Keywords: communal sheep farmers, Eastern Cape Province, season, sheep scab control methods, sheep scab.

Treatment of sheep prior to movement: its contribution to an effective scab (psoroptic mange) management strategy

BackgroundOvine psoroptic mange (sheep scab) is an important disease of sheep worldwide caused by the parasitic mite, Psoroptes ovis. It has a negative impact on animal welfare and leads to significant economic losses for the sheep industry. Effective and targeted management is required to limit its transmission.MethodsA stochastic metapopulation model of sheep scab transmission is used to investigate the contribution of the treatment of sheep prior to movements to sales, gatherings (predominantly markets) and away grazing to the reduction of prevalence of farms with scab in Great Britain.ResultsTreatment prior to movement to gatherings resulted in an 86% reduction in the overall prevalence of farms with scab and was more effective at reducing the overall prevalence of farms with scab than treatment before other categories of movements. The relative risk of farms having scab infection was inversely related to the percentage of farms which treated, but this relationship was not linear, with the biggest declines in the prevalence of farms with scab being achieved by small percentages of farms treating; a 50% relative reduction in the farm prevalence was achieved with only 15% of farms treating prior to gathering movements.ConclusionsThe results suggest that pre-movement treatment of sheep could make an important contribution to national scab control and, in practice, the approach could be more highly targeted if used in conjunction with known geographic and management risk factors for scab.Graphical

Methods to develop and evaluate attitudinal scales to measure farmer perceptions: Using sheep scab as an example.

There is limited information on the attitudes and opinions of British sheep farmers when preventing and managing sheep scab in their flocks. Attitudes are examples of latent traits, which are not directly observable. They must be measured indirectly which can be achieved using measurement scales. Attitudinal measurement scales are used frequently in research, but are seldom evaluated prior to use, particularly in veterinary research. Therefore, the aim of this study was to identify and assess latent traits which influence the control of sheep scab with the use of exploratory factor analysis, and then further evaluate these factors with the use of item response theory to determine how they perform as scales. An online survey was completed by 726 British sheep farmers during October 2021 (725 useable responses), which included a section with 37 belief statements related to the opinions and attitudes of sheep farmers around the management of sheep scab. These belief statements were developed and adapted from previous research. During the analysis, they were subjected to exploratory factor analysis, which suggested that the scales performed reasonably well. The scales were then evaluated further by item response theory. The graded response models for each attitudinal scale were assessed by graphical evaluation. They demonstrated that the scales were able to distinguish those respondents with low perceptions of control, responsibility, and trust, and those who had high perceptions of luck. This study provides insights into some of the factors influencing the management of sheep scab, and how well these scales perform. Additionally, it further highlights the importance of evaluating attitudinal scales for use in research, and that exploratory factor analysis alone does not provide enough information on how well they perform.

Prevention of psoroptosis of sheep in Dagestan Republic in winter

Relevance. Sheep breeding in Dagestan has its own distinctive features compared to other regions, territories and republics of our country. They are associated with extremely diverse natural and climatic conditions of various geographical zones of the republic. Currently, preventive measures against psoroptosis of sheep and goats in the Caspian region of Russia are carried out by practitioners and workers of farms of various forms of ownership using outdated acaricidal agents of past generations. The main peak of psoroptosis of sheep in the Republic of Dagestan falls on the autumn-spring period — from November to mid-December and from March to May. At this time, bathing activities are not possible, the injection method is not always convenient, especially taking into account pregnant queens and young animals, spraying is ineffective and carries the risk of hypothermia of animals. It follows from the above that the search for acaricidal agents capable of preventing psoroptosis of sheep in winter on the territory of the Caspian region of Russia is of great scientific and practical importance.Results. The experimental data obtained allow us to conclude that the preventive use of the acaricidal agent Delcid 7.5 in a dosage of 10 ml per 50 kg of live weight provides protection against Psoroptes ovis for up to 23 days, Sanofly — up to 18, which is 5 days less. Delcid 7.5 turned out to be 10% more effective in acaricidal action, as well as in the number of new lesions on average per animal with an indicator of 1, whereas after Sanoflaya, this indicator reached 2 after 23 days of the experiment. The reasons for the results obtained are various main active substances and their acaricidal effect against the Psoroptes ovis tick, in Delcid 7.5 it is deltametrin, in Sanoflaya it is cyflutrin.