Disease In Cattle Research Articles

Mainstreaming Indigenous Knowledge of Pastoralists into Climate Change Policies in Cameroon

Indigenous pastoralists are hardest hit by the impacts of climate change because of their dependence on nature and limited adaptation. This paper seeks to examine the level of integration of traditional knowledge systems into adaptation policies in Cameroon, using the specific case of Mbororo pastoralists in the Western Highlands. Using a mainly qualitative approach in data collection, in-depth interviews were conducted with 28 purposively selected pastoralists from 4 divisions with intense pastoral activity, comprising 19 Mbororo pastoralists, 2 members of the Mbororo Social and Cultural Association (MBOSCUDA), 2 Mbororo traditional rulers, 5 Mbororo women and one focus group discussion. Discussions were recorded and voice notes were transcribed, coded and treated according to content and thematic with the aid of Atlas. Ti software. Results show that Mbororo pastoralists migrated into the region in the 1950s as nomadic herders and occupied marginal lands due to the nature of their activity. With climatic aberrations being acute, their closeness to nature permitted them to develop a wide array of knowledge and traditional practices to adapt and exploit existing opportunities. Semi-nomadic and transhumance methods of rearing, cross-breeding local species with high-breed species to produce resistant breeds of cattle, cultivating resistant pasture species, rotational grazing and using traditional medicines to treat cattle diseases have reduced resource degradation and curbed the effects of climatic aberrations. Nevertheless, these indigenous knowledge systems are eroding fast due to poor indigenous institutions and non-integration into policy. This work will reinforce capacities of decentralized communities in developing and implementing local adaptation plans on climate change.

Molecular study of some vector–borne diseases in cattle raised in western Türkiye

Unfortunately, global warming, especially the global climate crisis, increases the rate of vector–borne infections. Among the causes of this infection are microorganisms in the Rickettsiales Order, which are Gram–negative and small coccobacillus microorganisms that can multiply within host cells and are dependent on their metabolism, in addition to bacterial infections, protozoa such as Babesia spp. and Theileria spp. are transmitted through vectors and cause serious diseases in animals. This study aimed to investigate the presence of some vector–borne bacterial and protozoan microorganisms in blood samples taken from cattle raised in Mugla province, located in the West of Türkiye, and to reveal relevant disease data for the region. In this study, blood samples taken from 100 cattle were examined using molecular methods. While Anaplasma phagocytophilum was detected in 15 blood samples (15%), Anaplasma ovis agent was detected in eight samples (8%). Anaplasma bovis agent (1%) was identified in only one blood sample. In the samples examined within the scope of the study, Ehrlichia and Rickettsia species from bacteria and Theileria spp. and Babesia spp. from parasitic agents could not be detected. Mugla province, located west of Türkiye, has a subtropical dry summer climate, so the probability of infections transmitted through arthropods is high. Since the agents are transmitted through ticks, conducting more studies on vector–borne diseases is essential. This includes mapping the region’s vector ticks and determining and evaluating the tick carrier and disease maps in cattle. The data obtained is thought to help create regional and national vector–borne disease maps.

Nodular skin disease in cattle.

This focus article was prepared by Caroline Fenemore and Vanessa Swinson of the APHA Cattle Species Expert Group, with Aiden Foster of the University of Bristol (Farm Animal Pathology Services).

Strategic Infectious Diseases in Beef Cattle in Balongpanggang during 2023

Strategic infectious animal diseases have a great impact on the national economy as they may cause great economic loss, public anxiety, and high mortality. In Indonesia, among the diseases considered as strategic infectious animal diseases is foot and mouth disease (FMD). This study reported the incidence of strategic infectious animal diseases in Balongpanggang district during 2023. Throughout 2023, FMD only accounted for 4% of the total diseases of the year and was the only strategic infectious animal disease reported that year. Meanwhile, bovine ephemeral fever (BEF) incidence reached 57% (876/1546) of the total diseases in beef cattle in 2023. In addition to BEF, official veterinary services reported a total case of 1546 throughout 2023 that comprises; diarrhea (99), limping (24), helminthiasis (91), ectoparasite (11), hematochezia (3), wound (3), mastitis (4), allergy (1), dystocia (28), vaginal prolapse (11), dermatitis (45), enteritis (27), tympani (11), scabiosis (122), arthritis (67), ophthalmic problem (11), endometritis (1), uterine retention (13), indigestion (2), pneumonia (21), hypoglycemia (5), abscess (21), ovariohysterectomy (1), orchitis (1), intoxication (1), and papilloma (1). In conclusion, the only strategic infectious animal disease reported in 2023 in Balongpanggang was FMD with the incidence as high as 3% as compared to the non-strategic infectious animal diseases, BEF, which reached 54% of the total cases during 2023.

Sensitivity of dairy calf Salmonella enterica serotype Cerro isolates to infection-relevant stressors.

Salmonella enterica serotype Cerro (S. Cerro) is an emerging Salmonella serotype isolated from cattle, but the association of S. Cerro with disease is not well understood. While comparative genomic analyses of bovine S. Cerro isolates have indicated mutations in elements associated with virulence, the correlation of S. Cerro fecal shedding with clinical disease in cattle varies between epidemiologic studies. The primary objective of this study was to characterize the infection-relevant phenotypes of S. Cerro fecal isolates obtained from neonatal calves born on a dairy farm in Wisconsin, USA. The S. Cerro isolates varied in biofilm production and sensitivity to the bile salt deoxycholate. All S. Cerro isolates were sensitive to sodium hypochlorite, hydrogen peroxide, and acidic shock. However, S. Cerro isolates were resistant to nitric oxide stress. Two S. Cerro isolates were unable to compete with S. Typhimurium during infection of calf ligated intestinal loops, indicating decreased fitness in vivo. Together, our data suggest that S. Cerro is sensitive to some innate antimicrobial defenses present in the gut, many of which are also used to control Salmonella in the environment. The observed phenotypic variation in S. Cerro isolates from a single farm suggest phenotypic plasticity that could impact infectious potential, transmission, and persistence on a farm.IMPORTANCESalmonella enterica is a zoonotic pathogen that threatens both human and animal health. Salmonella enterica serotype Cerro is being isolated from cattle at increasing frequency over the past two decades; however, its association with clinical disease is unclear. The goal of this study was to characterize infection-relevant phenotypes of S. Cerro isolates obtained from dairy calves from a single farm. Our work shows that there can be variation among temporally related S. Cerro isolates and that these isolates are sensitive to killing by toxic compounds of the innate immune system and those used for environmental control of Salmonella. This work contributes to our understanding of the pathogenic potential of the emerging pathogen S. Cerro.

Identification of DNA methylation markers for age and Bovine Respiratory Disease in dairy cattle: A pilot study based on Reduced Representation Bisulfite Sequencing

Methylation profiles of animals are known to differ by age and disease status. Bovine respiratory disease (BRD), a complex infectious disease, primarily affects calves and has significant impact on animal welfare and the cattle industry, due to production losses, increased veterinary costs as well as animal losses. BRD susceptibility is multifactorial, influenced by both environmental and genetic factors. We have performed a pilot study to investigate the epigenetic profile of BRD susceptibility in six calves (three healthy versus three diagnosed with BRD) and age-related methylation differences between healthy calves and adult dairy cows (three calves versus four adult cows) using Reduced Representation Bisulfite Sequencing (RRBS). We identified 2537 genes within differentially methylated regions between calves and adults. Functional analysis revealed enrichment of developmental pathways including cell fate commitment and tissue morphogenesis. Between healthy and BRD affected calves, 964 genes were identified within differentially methylated regions. Immune and vasculature regulatory pathways were enriched and key candidates in BRD susceptibility involved in complement cascade regulation, vasoconstriction and respiratory cilia structure and function were identified. Further studies with a greater sample size are needed to validate these findings and formulate integration into breeding programmes aiming to increase animal longevity and disease resistance.

Hot topic: Avian influenza subtype H5N1 in US dairy—A preliminary dairy foods perspective

In February and March of 2024, an unusual illness began affecting dairy herds primarily in Texas and neighboring states. The causative agent of this illness was ultimately confirmed in late March 2024 to be a strain of highly pathogenic avian influenza H5N1 belonging to clade 2.3.4.4b. In the months following the emergence of this viral disease in cattle, infections have spread to at least 191 herds in 13 states at the time of this writing in August 2024, primarily through cattle and human movement. Surprisingly, early examination of raw milk samples from clinically affected animals indicated that the virus had an affinity for the mammary tissue, and viral shedding into raw milk occurred at high levels, exceeding 108 log10 50% tissue culture infectious dose (TCID50) in some cases. These high viral loads coupled with evidence that farm cats who consumed raw milk from clinically ill animals were infected and exhibited high mortality rates, raised concerns about the safety of the US milk supply for human consumption. To date, 4 cow-associated human infections have been reported, all from farm employees with direct contact with infected animals. Several parameters ultimately affect the theoretical public health risk from consumption of dairy products manufactured from a milk supply containing H5N1, namely (1) initial viral load, (2) persistence of H5N1 in raw milk, (3) viral inactivation through processing practices including pasteurization, and (4) human susceptibility and infectious dose. In the short period since the emergence of this disease in dairy cattle in the United States, research has begun to answer these critical questions, although our knowledge is still quite limited at this time. Here we review the literature available from the current H5N1 outbreak in US dairy cattle, as well as selected relevant literature from previous research in other animal agriculture sectors, that affect our current understanding of the parameters associated with the food safety risk of this disease in the US dairy supply chain.

Risk factors for introduction of BVDV in the context of a mandatory control program in Dutch dairy herds.

Bovine Viral Diarrhea Virus (BVDV) is a common viral disease in cattle, causing economic losses in naive herds where the virus is introduced. In the Netherlands, a BVDV control program has been in place since 1998, evolving from voluntary to mandatory participation for dairy herds since April 2018. Participation in the BVDV control program is not mandatory for non-dairy farms. The aim of this study was to determine risk factors for new introduction of BVDV into certified BVDV-free herds in the context of a national BVDV control program in dairy herds. In this retrospective case-control study, survey data were collected from 149 dairy farms that lost their BVDV-free status (case herds) and 148 matched dairy farms that maintained their BVDV-free status (control herds) between 2018 and 2021. The survey captured information about potential risk factors and herd characteristics in the 2 years leading up to the loss of BVDV-free status (case herds, virus detection in at least one animal or when seroconversion was detected) or remaining BVDV-free (control herds). Descriptive statistics and logistic regression with a backward selection and elimination procedure were used to identify potential risk factors associated with losing BVDV-free status. Risk factors were quantified as an Odds Ratio (OR) with the associated 95% confidence interval (CI). The risk factor with the highest OR for losing BVDV-free status was purchasing cattle from herds without BVDV-free status (OR 1.25, CI 1.10-1.41), followed by the farmer having another profession that resulted in contact with other cattle (OR 1.25, CI 1.06-1.47), housing young calves and adult cows in the same barn (OR 1.22, CI 1.08-1.38), having a permanent employee on the farm (OR 1.17, CI 1.04-1.31), having a group calving pen (OR 1.16, CI 1.03-1.32), escaped cattle from other farms that mingled with own cattle (OR 1.16, CI 1.01-1.33), and nearest distance to a non-dairy farm (OR 1.15, CI 1.03-1.28). Although the BVDV status of most dairy herds can be checked in an open register, approximately half of the farmers indicated that they purchased cattle from BVDV-free herds while they were actually purchasing from non-BVDV-free farms. Farmers should be stimulated to actively check the true BVDV status of the herd from which cattle are purchased to further reduce the risk of introduction. In addition, indirect contact with cattle from other farms through either the farmer or other on-farm staff should be avoided. It is strongly advised to work in these situations with proper biosecurity measures such as changing boots and coveralls. The results can be used to improve BVDV control programs to further decrease the prevalence.

The politics of rinderpest control on the Kenya–Tanganyika border, c. 1920–1940

ABSTRACT During the interwar period, Kenyan and Tanganyikan veterinarians sought to control rinderpest, Africa’s most dangerous cattle disease, with competing methods of vaccination. Tanganyikans used blood serums and quarantines, aiming to eradicate the virus, increase African herds, and above all protect the cattle of southern African settlers. Kenyan veterinarians, favoring settler cattle, used live virus alongside serums, believing that rinderpest in African reserves could not be eliminated because of proximity to wildlife carriers and an uncontrolled northern border. While Maasai pastoralists along the inter-territorial border preferred the Kenyan approach as less threatening to their livestock, they were forced to accommodate divergent methods of rinderpest control. Severe drought and historic claims to Tanganyikan pastures brought some Kenyan Maasai and their cattle across the border, undermining rinderpest controls and Tanganyikan Maasai land rights – sparking rinderpest epidemics that challenged Tanganyikan eradication measures. Vaccine breakthroughs after 1930 failed to stanch rinderpest, often carried by wildlife, while perceptions of an emergent Dust Bowl made some key officials sympathetic to cattle culling through disease. Drawing on archival sources, the article shows that despite protocols emphasizing cooperation, political disagreements and territorial disputes between British colonies frustrated the eradication of rinderpest in East Africa for another generation.

Article Review: The Role of Blood-sucking Insect Vectors in the Spread of Jembrana Disease in Bali Cattle

ABSTRACT. Jembrana disease is a contagious disease in cattle and causes enormous economic losses for farmers. This disease, known as bovine lentivirus, was first reported in 1964 in Jembrana District. Jembrana disease specifically attacks Bali cattle at various ages. The cause of this disease is a lentivirus from the Retoviridae family. Jembrana disease transmission occurs by direct contact and is mediated by blood-sucking insect vectors. Not all blood-sucking insects can be vectors for Jembrana disease. Some blood-sucking insects capable of spreading Jembrana disease are Tabanus rubidus flies Culicoides sp mosquitoes, and Aedes lineatopennis, which act as mechanical vectors. As for the Boophilus microplus tick, it is suspected that it acts as a biological vector. Even after re-testing the tick, it could not prove its role as a biological vector for JDV. Prevention and control of this disease can be carried out by vaccination, biosecurity, biosafety, administration of vitamins, isolation of infected livestock, and control of blood-sucking insect vectors by administering insecticides to cages.

Ethno veterinary practices for cattle amongst traditional veterinary health care practitioners in palayamkottai, tirunelveli, tamilnadu

In the Palayamkottai, tirunelveli in tamilnadu, people make extensive use of medicinal plants to treat a number of diseases in cattle. The aim of the study was to identify the medicinal plants used to treat various ailments in cattle. Ethno veterinary survey was carried out using questionnaire and individual interviews from June to July 2024 in Palayamkottai, Tirunelveli district, Tamilnadu. The study identified total of 53 plants species divided into 31 families used in the various cattle ailments such as Foot and Mouth Disease, Dysentery, Mastitis, wound, bleeding horns, abscess, to improve milk production, pain and contusion due to trauma in Cattle by traditional veterinary health care practitioners. 16 internal and external applications are prepared by using these species. Species from the Fabaceae, Poaceae and Lamiaceae families are the most widely represented. Leaves, seeds, fruits and roots are the most commonly used parts. The results of the study provided all relevant information, particularly Ingredients, mode of preparation and route of administration.

How control and eradication of BVDV at farm level influences the occurrence of calf diseases and antimicrobial usage during the first six months of calf rearing

BackgroundBovine viral diarrhoea (BVD) is one of the major cattle diseases causing economic losses worldwide. Nowadays the disease manifests mainly as virus-induced immunosuppression and early embryonic death, impacting overall herd performance and contributing to increased antibiotic usage in calf rearing.MethodsIn our study we investigated the effect of rapid BVDV control measures on calf diseases and antimicrobial usage after weaning on a large industrial dairy farm. Persistently infected (PI) animals were identified and removed from the herd within a short period of time, and all susceptible animals were vaccinated against BVDV. Recorded herd parameters and AB usage were monitored retrospectively and compared with data collected after starting the BVD control program.Results and discussionThe programme began in January 2023 with identifying and eliminating PI animals from the farm. Twenty-one PI animals were found by using RT-qPCR testing of blood sera out of the 1571 animals tested (1.33%). Subsequent testing (January and December 2023) identified further 28 PI animals amongst the 542 calves tested shortly after birth, and all were instantly removed from the farm. In parallel with the BVDV eradication measures, AB usage dropped by more than 50% compared to previous years. Calf mortality also decreased from 7.45 to 4.38% as the control program progressed. Correspondingly, both the number of respiratory and diarrhoea cases decreased dramatically on the farm while the eradication measures were in place.ConclusionOur study clearly demonstrated the positive effects of BVDV eradication on the improvement of calf health and importantly, a reduction of AB usage, contributing to the One Health perspective of farm animal production.

Epidemiology, genetic characterization and population structure analysis of lumpy skin disease virus from North India.

Lumpy skin disease (LSD) is a transboundary, viral disease of cattle with a significant economic impact on the livestock industry. This study describes the epidemiological investigations of outbreaks of LSD that occurred in 2022 in three Indian states viz., Haryana, Himachal Pradesh and Rajasthan and the genetic characterization of Lumpy skin disease viruses (LSDVs). Also, the population structure analysis of LSDVs was carried out. Out of 138 scab samples tested from suspected cattle for LSDV, 106 were found positive. Of these, nine representative scab samples were further genetically characterized. Phylogenetic analysis based on the P32 and EEV gene sequences depicted that the LSDV strains of the present study had nucleotide identity of 100% and 99.10-99.45%, respectively with the LSDV/2019 field strains of India. Multiple sequence alignment of the EEV glycoprotein gene sequences revealed nucleotide polymorphisms at three positions viz., G178A, G253A and A459G in circulating LSDV/2022 field strains. Based on the median joining network analysis of the EEV gene, 12 haplotypes were identified among the LSDV populations. Population structure analysis corresponding to the EEV gene revealed high haplotype (0.8486 ± 0.026) and low nucleotide diversities (0.00636 ± 0.0006) and negative values for neutrality indices, indicating a high number of closely related haplotypes and the studied population may have undergone a recent expansion. The findings will help in understanding the distribution and dynamics of LSDV populations, which will prove pivotal in designing and implementing effective management and control strategies.

Genome-Wide Association Study (GWAS) for Left Displaced Abomasum in Highly Productive Russian Holstein Cattle.

Left displaced abomasum (LDA) is a multifactorial disease of cattle that occurs mainly during the transition postpartum period and is characterized by a decrease in milk production and an increased risk of culling. Several studies have been conducted confirming the hereditary nature of predisposition to this disease. The aim of our study is to identify genetic associations characterizing the genomic variability of susceptibility to LDA in Holstein cattle of the Leningrad region of the Russian Federation. The objects of this study were 360 highly productive dairy cows divided into two groups: animals with LDA, and healthy ones (control). Runs of homozygosity analysis revealed one ROH on BTA13 that was found to be significantly more prevalent in the group of animals with LDA than in the healthy group. Fourteen candidate SNPs were found to be nominally associated with left displacement of the abomasum (p-value < 1 × 10-4). When performing functional annotation of genes containing associated polymorphisms or located close to them, candidate genes presumably associated with the development of LDA were identified: ABCB11, SRP72, RGS18, SOX4, GSG1L, FBXL19, and PNPLA4.

PSLBI-15 Effects of heat shock protein 70 on cell viability and protective capacity of serum against histone cytotoxicity

Abstract Bovine respiratory disease (BRD) is the most significant health problem associated with newly received cattle in the beef industry. Serum concentrations of extracellular histones increase in a variety of diseases and histones are known to be cytotoxic to mammalian cells. Work in our lab indicated that failure to protect against cytotoxic effects of extracellular histones may be a component of severe cases of respiratory disease in cattle. The mechanisms or proteins that neutralize cytotoxic effects of extracellular histones are not fully elucidated, but C-reactive protein and complement activity have been associated with a reduced cytotoxic effect of extracellular histones. Work in the literature suggests that heat shock protein 70 (HSP70) concentrations in the serum is increased in disease and may directly activate complement. Unpublished observations in our lab indicated that HSP70 potentially interacts with histones to exacerbate cytotoxicity leading to our hypothesis that increased concentrations of HSP70 will decrease the protective capacity against histone cytotoxicity. Therefore, the objectives of the current study were to evaluate serum concentrations of HSP70 in weaned bulls entering the feedlot and the effects of increasing HSP70 concentrations on histone cytotoxicity in vitro. Weaned seedstock bulls (n = 130) composed of various breeds were fed using the GrowSafe System at the Tucumcari Bull Test for 122 d. At receiving, blood samples were obtained via coccygeal venipuncture, centrifuged, and serum immediately frozen on dry ice. Serum was analyzed for complement activity (CH50 assay) and protective capacity against extracellular histones using our novel histone toxicity assay. The ratio value of histone toxicity to CH50 was used to separate a subset of bulls as protective (n = 10) and non-protective (n = 10). Concentrations of HSP70 were quantified utilizing a commercially available ELISA kit. Data were analyzed using the GLM procedure of SAS. Serum concentrations of HSP70 were similar (P &amp;gt; 0.10) for protective and non-protective bulls. To test the responses to increased concentrations of HSP70 to mimic disease, protective and non-protective serum was tested against histones alone and in combination with 0.5 or 40 ng/mL recombinant bovine HSP70. Complement activity from protective and non-protective bulls was not influenced (P &amp;gt; 0.10) in the presence and absence of recombinant bovine HSP70. Exogenous HSP70 at 0.5 or 40 ng/mL did not influence protective capacity in non-protective animals (P = 0.95). However, HSP70 at 0.5 ng/mL did not (P = 0.18) reduce protective capacity and reduced protective capacity (P &amp;lt; 0.01) at 40 ng/mL in serum from bulls that were assigned to the protective group. Results indicate that weaned bulls entering the feedlot display varied capacity to protect against histone toxicity and increased concentrations of HSP70 can reduce the protective capacity indicating that circulating HSP70 may play a role in bovine respiratory disease pathogenesis.

Prevalence of lumpy skin disease in cattle at Netrokona sadar in Bangladesh

Cattle farming is a significant contributor to the socio-economic development of Bangladesh. However, infectious diseases continuously challenge cattle farming, causing tremendous losses to farmers. Among the diseases, Lumpy Skin Disease (LSD) has become a major burden in recent years. This study was conducted to reveal the prevalence of LSD in cattle in Netrokona Sadar Upazila. Data were collected directly from the cattle farmers at Upazila Veterinary Hospital (UVH), by visiting farms, and retrospectively from the register book of UVH from November 2022 to October 2023. Of the total of 2511 observed cattle, the prevalence of LSD was the second highest (16.97%). We further investigated the prevalence of LSD according to age, sex, breed, season, vaccination status, nutrition, hygiene, and deworming. LSD was more prevalent in young (17.67%), females (18.25%), cross-breed (23.96%), and non-vaccinated (17.28%) cattle. A higher prevalence was also found in the summer (38.77%) than in other seasons. Furthermore, we found more prevalence in cattle provided with traditional diets (18.22%), in unhygienic management (17.33%), and non-dewormed (18.63%) cattle. The findings illustrated that sex, immunization status, season of the year, and diet were significantly (p&lt;0.01) associated with the prevalence of LSD. The study will aid stakeholders in evaluating the current state of LSD in the area and developing effective control strategies against it. Res. Agric. Livest. Fish. Vol. 11, No. 2, August 2024: 137-147

Prevalence of camel trypanosomosis and herders’ knowledge, attitude, and practices towards the disease in the pastoral area of southern Ethiopia

BackgroundSurra is a parasitic disease caused by Trypanosoma evansi that threatens the health and productivity of camels. Despite its significant impact on camels in Ethiopia, surra has not received as much attention as diseases in cattle and other domestic animals. The objective of the study was to estimate the prevalence of surra, identify the potential risk factors and assess the traditional knowledge, attitude and practices of camel herders towards the disease.MethodsThe study used a parasitological and participatory epidemiological (PE) approach. Between February and July 2022, a total of 335 blood samples were collected from camels across three districts and tested using the buffy coat technique. The PE investigation involved six key informant groups consisting of 8 to 12 key persons, and used a semi-structured interview and various PE tools and principles.ResultThe study found that the prevalence of surra among examined camels was 3.9% (95% CI: 2.1–6.5). The prevalence was significantly higher in camels with a poor body condition score (BCS) (OR = 9.3; 95% CI: 1.8–47.5; p = 0.008) compared with camels with a good BCS. However, district, age, sex, and ethnicity had no effect on the prevalence of surra (p > 0.05). The study also found that the packed cell volume (PCV) was significantly lower (p < 0.0001) in parasitaemic animals (18.92 ± 2.63) than in aparasitaemic animals (25.13 ± 4.56). Camels with poor BCS (22.7 ± 3.5) had a significantly (p < 0.001) lower mean PCV than camels with good BCS (26.2 ± 5.0). The PE investigation showed that all the camel herders were well aware of surra, known locally as Dhukana. The clinical symptoms, the season of high incidence, routes of transmission, impact on production, and control methods were accurately described. Moreover, this study emphasized that surra is the primary disease affecting camel health and productivity.ConclusionThe study identified a moderate prevalence of surra in the research area. To reduce surra incidence and associated losses, enhancing veterinary services and providing support for proper camel husbandry practices in the region is recommended. Additionally, future studies should consider using more sensitive and specific techniques like serological and molecular assays, as this study relied on microscopy only.

Lumpy skin disease virus isolation, experimental infection, and evaluation of disease development in a calf

Lumpy skin disease (LSD) is one of the most economically significant viral diseases of cattle caused by the Lumpy Skin Disease Virus (LSDV), classified as a member of the genus Capripoxvirus and belongs to the family Poxviridae. Nodular skin samples were collected from clinically sick cattle in the districts of Amuru and Wara Jarso Ethiopia to isolate LSD virus. The virus was isolated using primary lamb testis and kidney cells. The isolated LSDV was infected into a healthy calf while maintaining the necessary biosecurity measures to generate skin lesions and to assess disease progression using postmortem examinations. On the fourth day after virus inoculation, the calf developed typical LSD skin nodules with increased rectal temperature, which lasted until the 12th day, when they began to decrease. Viral shedding was detected in nasal, oral, and conjunctival swabs from 6 to 14 days after infection using real-time PCR. Post-mortem tissue specimens tested positive for LSD virus using real-time PCR and virus isolation. This study showed that LSDV were responsible for the LSD outbreaks, and the appearance of typical skin nodules accompanied by fever (> 39.5 °C) defined the virus’s virulent status. The experimental infection with the isolated infectious LSDV could serve as a platform for future vaccine evaluation study using an LSDV challenge model.

Multiplex reverse transcription recombinase polymerase amplification combined with lateral flow biosensor for simultaneous detection of three viral pathogens in cattle

Bovine viral diarrhea virus (BVDV), bovine epidemic fever virus (BEFV), and bovine respiratory syncytial virus (BRSV) cause respiratory symptoms in cattle. The absence of rapid, precise, and easily accessible diagnostic methods poses difficulties for herders and veterinary epidemiologists during outbreaks of major infectious animal diseases. Considering the mixed infection of viruses, a multiple-detection method, reverse transcription recombinase polymerase amplification (mRT-RPA) combined with a lateral flow biosensor (LFB), was established to simultaneously detect the three pathogens. This technique is based on the specific binding of three differently labeled RT-RPA products (DNA sequences) to antibodies on the three test lines of the LFB, achieving multiplex detection through the presence or absence of coloration on the LFB test lines. The fluorescence values of the LFB test lines are recorded by a test strip reader. The mRT-RPA-LFB assay completes detection at a constant temperature of 41 °C within 33 min. The limits of detection (LODs) for BVDV, BEFV and BRSV were 2.62 × 101, 2.42 × 101 and 2.56 × 101 copies/μL, respectively. No cross-reactivity was observed with the other six bovine viruses. The developed method showed satisfactory intra- and inter-assay precision, and the average coefficients of variation were ranged from 2.92 % to 3.99 %. The diagnostic sensitivity and specificity were 98.11 % and 100 %, respectively, which were highly consistent with the RT-qPCR assay, and the kappa value was 0.988 (95 % confidence interval, CI). In general, the mRT-RPA-LFB assay has the potential to become a powerful tool for rapid screening of cattle diseases because of its advantages such as fast detection speed, convenient operation, strong specificity, and high sensitivity.

Development of polymerase chain reaction-lateral flow dipstick assay for detection of Mycoplasma bovis in cattle

Mycoplasma bovis (M. bovis) is capable of causing a range of diseases in cattle, encompassing calf pneumonia, arthritis, conjunctivitis, meningitis, and mastitis. It is widely recognized as one of the predominant pathogens posing a significant threat to the global cattle industry. Therefore, accurate and sensitive methods are urgently needed to detect M. bovis. This study aims to detect M. bovis by combining colloidal gold with biotin-labeled oligonucleotides to improve detection sensitivity and form a chromogenic detection probe based on signal amplification technology. Here, we developed a sensitive and specific polymerase chain reaction-lateral flow dipstick assay (PCR-LFD) strip for efficient nucleic acid detection of M. bovis. A pair of specific primers with 5’ ends labeled with biotin and digoxigenin probes was designed for PCR experiments. Colloidal gold particles-labeled anti-digoxigenin IgG coated gold-labeled test strip was prepared, streptavidin was used as the detection probe, and nitrocellulose membrane coated goat anti-mouse IgG was used as the control line. Our results showed that the detection limit of the PCR-LFD was 89 fg/µL for the M. bovis DNA. The results from the test strip were highly consistent with those from real-time qPCR. This assay were highly specific for M. bovis, as there were no cross-reactions with other microorganisms tested and the detection sensitivity of the test was also relatively high (97.67%). The novel strips present a promising tool for the cost-effective and sensitive diagnosis of M. bovis.