Antimicrobial resistance (AMR) is a global threat, and responsible antimicrobial use (AMU) in animals is crucial. However, AMR development is influenced by numerous factors. This scoping review aims to describe the association between AMR, AMU, and other risk factors in European livestock farms. Understanding the impact of different risk factors is essential for mitigating AMR. The results confirm that the AMR prevalence varies between livestock farms and that AMU affects this prevalence. At herd level, factors related to infection pressure and AMU have been predominantly studied and are often associated with AMR. Only a few other factors such as temperature and metals or disinfectants in the farm environment have been investigated. Overall, the associations between AMR and the studied farm level. Risk factors, including AMU, were variable and complex. The studies varied in their methodological approaches. Different AMR indicators were used, with phenotypic resistance in indicator Escherichia coli being most common, and resistome characterisation gaining interest in recent years. Some studies did not include AMU data or had insufficiently detailed data, while some calculated treatment incidences in different ways. Standardised measures for risk factors and outcome variables would facilitate comparisons between studies and meta-analyses. For deeper insights into resistance dynamics, resistome characterisation is preferable, whereas phenotypic characterisation of pathogenic bacteria is more appropriate for developing clinical guidelines, and resistance profiles in indicator bacteria are useful for monitoring. In conclusion, farm-level risk factors are complex and risk factor studies including AMU, using validated methods, sufficient sample sizes, and sound statistical analyses are still needed.
Thelaziasis, also known as thelaziosis, is a neglected vector-borne disease caused by parasitic nematodes from the genus Thelazia, belonging to the family Thelaziidae. The disease is transmitted biologically by various fly species, including the genus Musca (family Muscidae), Phortica (family Drosophilidae), and Fannia (family Fanniidae). These flies act as intermediate hosts (IHs) by depositing infective third-stage larvae (L3) during their tear feeding. Thelazia spp., such as T. gulosa, T. skrjabini, and T. rhodesi, inhabit the ocular regions of various animals, including humans and birds. Adult Thelazia worms are slender and creamy-white, measuring between 8-12 mm in males and 12-21 mm in females, with females releasing live larvae into the host's tear secretions. The presence of these parasites can lead to serious ocular conditions such as keratitis, conjunctivitis, and even blindness. Diagnosis typically involves identifying the adult nematodes in the conjunctival sac, where they appear as active, slender, creamy-white organisms. Management of the infection can include the physical removal of the parasites and the use of effective anthelmintics like Eprinomectin, Doramectin, Ivermectin and Levamisole, administered either subcutaneously or intramuscularly. Regular deworming and treatment of infected animals are essential practices in areas where the disease is endemic, and effective prevention and control strategies are necessary to mitigate its impact. Hence, this comprehensive review has provided updated information about the oldest known but neglected and re-emerging parasitic disease in bovines worldwide.
Veterinary Teaching Hospitals (VTHs) represent complex environments that integrate clinical care, education, and research, posing unique biosecurity challenges. In response to increasing scrutiny from accreditation bodies such as the European Association of Establishments for Veterinary Education (EAEVE), there is a growing need for rigorous, evidence-based biosecurity protocols. This review critically analyses internationally recognised protocols - including those of the University of Liège, the American Association of Equine Practitioners (AAEP), and leading small animal institutions - as well as scientific literature addressing best practices in infection control. We identify key components of successful biosecurity programmes, including risk-based patient classification systems, standardised hygiene and disinfection protocols, and the mandatory training for staff and students. Particular emphasis is placed on the difficulties encountered in teaching contexts, where high human-animal interaction increases the risk of zoonoses and nosocomial infections. A comprehensive set of recommendations is presented to support the development of scalable and institutionally adapted biosecurity protocols, with the aim of ensuring the safety of patients, staff, students, and visitors in VTHs while meeting international accreditation standards.
African swine fever (ASF) is a highly contagious animal disease caused by African swine fever virus (ASFV). It is listed by the World Organization for Animal Health (WOAH) as an animal disease subject to statutory reporting. ASFV, a large, enveloped double-stranded DNA virus with high genomic complexity, exhibits a case fatality rate of up to 100%, posing a significant threat to the global pig industry and food safety. To date, the absence of a safe commercial ASFV vaccine primarily stems from challenges in identifying immunogenic viral antigens, insufficient characterization of ASFV pathogenesis, and limited understanding of the virus's immune evasion mechanisms. Here, we review the pathogenic characteristics (morphological structure, clinical symptoms, and epidemiological characteristics), molecular biological characteristics, and infection mechanism of ASFV, as well as the immune response mechanism, vaccine research, and the latest information on ASFV in other areas. This review will be in favour of understanding the current state of knowledge of ASF and developing effective vaccines to control this disease.
Preventing neonatal calf diarrhea (NCD) and bovine respiratory disease (BRD) in cow-calf herds is essential to optimizing calfhood health. Disease control can prevent morbidity and mortality; however, evidence concerning the effectiveness of practices to achieve this is limited. The objective of this systematic review was to assess and summarize the evidence on the effectiveness of management practices to prevent calf morbidity and mortality from NCD and BRD in beef cow-calf herds. The population of interest was preweaned beef calves. The outcomes were calf morbidity and mortality caused by NCD and BRD. Only studies reporting naturally occurring diseases were included. Seventeen studies were deemed relevant, 6 studies of which were controlled trials or randomized controlled trials (RCTs), and 11 were observational studies. Most management practices had some evidence to support their use; however, the certainty of the findings was low to very low. Most of the practices were shown to impact both NCD and BRD. Yet, the different levels of consistency in the directionality of the findings suggest that some outcomes are more affected by some practices than others. More well-designed RCTs and cohort studies are required to provide reliable estimates to support recommended practices for cow-calf herds.
Our analysis covers 122 scientific publications about health issues in free-ranging Neotropical ungulates produced between 1990 and 2022, with an emphasis on the epidemiology of infectious diseases and parasites. Most studies focus on parasitology (43.4%) and bacteriology (15.6%), while body condition (0.8%), toxicology (1.6%), virology (6.6%), and health assessments (6.6%) are less studied. Brocket deer (Mazama americana and M. gouazoubira), followed by peccaries (Pecari tajacu and Tayassu pecari), and the lowland tapir (Tapirus terrestris) were the most frequent species surveyed (61.4% of all publications). We detected considerably higher numbers of studies and health topics covered in Brazil (n = 64; 52.5% of the total) compared to other Latin American countries. We emphasize the need for further research focused on poorly known health aspects of Neotropical ungulates that have received little attention in the past, especially the Chacoan peccary (Catagonus wagneri), taruca deer (Hippocamelus antisensis), Northern pudu (Pudu mephistopheles), and the least known Mazama species. Ecotoxicology and pathology studies are necessary to evaluate the impact of agrochemicals and other human disturbances on Neotropical ungulate populations in the wild. We encourage further research on the human impacts and trends of change in the epidemiology of infectious diseases, parasites, and health status of Neotropical wild ungulate populations.
This study aimed to highlight the roles of different minerals, serum metabolites, and hormones related to reproductive health of cattle as these have a significant role in cattle production and reproduction. Minerals are known for their contribution to several physiological processes such as cell formation and are paramount for physiological functions of vitamins, enzymes, and hormones. Evaluations of serum metabolites are good indicators of disease diagnosis and nutritional status in animals. Hormonal imbalance before and during pregnancy can negatively impact an overall bovine reproductive health. Minerals are important for reproduction, serum metabolites are a reliable indicator as their changes have been related to many disorders in reproduction, and hormones are significant indicators in cows presenting different reproductive conditions.
Anti-Müllerian hormone (AMH) is a dimeric glycoprotein belonging to the superfamily of the transforming growth factor-β. Due to the discovery of AMH functions, relative to the ovarian function, it is being postulated as being a highly important marker in studies on mammalian reproduction. Therefore, the objective of this review was to describe the role of this hormone in different reproductive aspects of female mammals, taking women, cows, and mares as reference species. The relationship between ovarian reserve and AMH was analysed, and it has been verified that there is a relationship between the latter, the antral follicle count, and the number of primary follicles. AMH concentration has been associated with parameters like the age of the individual, fertility, superovulation treatments and embryo production, and to the reproductive hormone concentration. Also, an association between AMH and female reproduction system diseases, and the fact that AMH is a heritable feature in the cow have also been proven. Recent studies have analysed the role of AMH receptor type 2 since it appears that, together with gonadotropin-releasing hormone, it controls the secretion of gonadotropins. Despite the considerable amount of bibliography on AMH, more studies are needed to complete the information that we have on it, in order to reveal the unknown elements in its action mechanisms.
Atypical porcine pestivirus (APPeV) is a pestivirus affecting pigs, notably causing high mortality in piglets due to neurological issues that impair suckling. This study reviews global literature from 2015 to March 2024, assessing APPeV prevalence. Analysing 40 relevant articles, it finds APPeV widely distributed across Europe, South America, North America, and Asia, with minimal presence in Africa and Australia. The scarcity in these regions might be due to geographical isolation, environmental factors, limited surveillance, diagnostics, or under-reporting. China leads in APPeV prevalence reports, followed by the USA, Germany, Sweden, and other countries. The main diagnostic methods are quantitative reverse transcription polymerase chain reaction (RT-qPCR) and RT-PCR, using tissue and serum samples. APPeV detection in the serum of boars and wild boars suggests possible persistent infections, indicating their role in APPeV epidemiology. Given the global outbreaks, particularly of congenital tremor (CT), the study calls for expanded research, especially in under-studied regions like Africa and Australia, focusing on healthy pigs, CT-affected piglets, and boars to better understand APPeV transmission dynamics.
Calves sold at weaning are the main source of income for cow-calf operations, and their survival should be a priority. Given this, the effective use of management practices for pregnant dams and calves to prevent calf mortality is essential; however, decision-makers often do not have access to information about the effectiveness of many management practices. A systematic review was conducted to summarize the evidence of the effectiveness of biosecurity, vaccination, colostrum management, breeding and calving season management, and nutritional management practices for preventing preweaned beef calf mortality. The population of interest was preweaned beef calves from birth until at least 3 months of age. The outcome of interest was general preweaning calf mortality with stillbirths excluded. Eleven studies were deemed relevant. Ten were observational cross-sectional studies, and one was a randomized controlled trial (RCT). The practices that were statistically significantly associated with calf mortality were intervening with colostrum in case a calf had not nursed from its dam or was assisted at calving, timing and length of the calving season, and injecting selenium and vitamin E at birth. More well-executed RCTs and cohort studies are needed to provide evidence of effectiveness and help support implementation of recommended practices in herds.
Due to the increasing demand for antibiotic-free livestock products from the consumer side and the ban on the use of antibiotic growth promoters, the poultry feed industry is increasingly interested in developing more alternatives to cope with this problem. Organic acids (butyric acid) have many beneficial effects on poultry health, performance, and egg quality when used in their diet, thus they can be considered for the replacement of antibiotics in livestock production systems. Butyric acid is most efficacious against pathogenic bacteria such as Salmonella spp. and Escherichia coli, and stimulates the population of beneficial gut bacteria. It is a primary energy source for colonocytes and augments the differentiation and maturation of the intestinal cells. Collectively, butyric acid should be considered as an alternative to antibiotic growth promoters, because it reduces pathogenic bacteria and their toxins, enhancing gut health thereby increasing nutrient digestibility, thus leading to improved growth performance and immunity among birds. The possible pathways and mechanisms through which butyric acid enhances gut health and production performance are discussed in this review. Detailed information about the use of butyric acid in poultry and its possible benefits under different conditions are also provided, and the impacts of butyric acid on egg quality and osteoporosis are noted.
Animal husbandry is increasingly under pressure to meet world food demand. Thus, strategies are sought to ensure this productivity increment. The objective of this review was to gather advances in the use of bacterial probiotics in animal production. Lactobacilli correspond to the most used bacterial group, with several beneficial effects already reported and described, as well as the Enterococcus and Pediococcus genera - being the latter expressively used in aquaculture. Research on the Bifidobacterium genus is mostly focused on human health, which demonstrates great effects on blood biochemical parameters. Such results sustain the possibility of expanding its use in veterinary medicine. Other groups commonly assessed for human medicine but with prospective expansion to animal health are the genera Leuconostoc and Streptococcus, which have been demonstrating interesting effects on the prevention of viral diseases, and in dentistry, respectively. Although bacteria from the genera Bacillus and Lactococcus also have great potential for use in animal production, a complete characterization of the candidate strain must be previously made, due to the existence of pathogenic and/or spoilage variants. It is noteworthy that a growing number of studies have investigated the genus Propionibacterium, but still in very early stages. However, the hitherto excellent results endorse its application. In this way, in addition to the fact that bacterial probiotics represent a promising approach to promote productivity increase in animal production, the application of other strains than the traditionally employed genera may allow the exploitation of novel mechanisms and enlighten unexplored possibilities.
Ectoparasites are important to the one health concept because their parasitism can result in the transmission of pathogens, allergic reactions, the release of toxins, morbidity, and even death of the host. Ectoparasites can affect host physiology, as reflected in immune defenses and body condition as well as hematological and biochemical parameters. Thus, evidence that ectoparasites influence host hematological parameters was systematically reviewed, and the methodological quality of these studies was analyzed. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed, and the studies included were limited to those that evaluated changes in hematological tests in ectoparasite-infested and non-infested animals, and bias and methodological quality were evaluated using the Animal Research: Reporting of In Vivo Experiments guideline. Thirty-four studies were selected and information about the host, ectoparasite infestation, blood collection, and analysis was collected and compared whenever possible. In this review, the presence of ectoparasites influenced both the red series and the white series of hematological parameters. Among the main parameters analyzed, hematocrit, red blood cells, hemoglobin, and lymphocytes showed reductions, probably due to ectoparasite blood-feeding, while including eosinophils, neutrophils, and basophils increased in infested animals due to the host immune response. However, methodologic improvements are needed to reduce the risk of bias, enhance the reproducibility of such studies, and ensure results aligned with the mechanisms that act in the ectoparasite-host relationship.
Antibiotic resistance has become a major health concern globally, with current predictions expecting deaths related to resistant infections to surpass those of cancer by 2050. Major efforts are being undertaken to develop derivative and novel alternatives to current antibiotic therapies in human medicine. What appears to be lacking however, are similar efforts into researching the application of those alternatives, such as (bacterio)phage therapy, in veterinary contexts. Agriculture is still undoubtedly the most prominent consumer of antibiotics, with up to 70% of annual antibiotic usage attributed to this sector, despite policies to reduce their use in food animals. This not only increases the risk of resistant infections spreading from farm to community but also the risk that animals may acquire species-specific infections that subvert treatment. While these diseases may not directly affect human welfare, they greatly affect the profit margin of industries reliant on livestock due to the cost of treatments and (more frequently) the losses associated with animal death. This means actively combatting animal infection not only benefits animal welfare but also global economies. In particular, targeting recurring or chronic conditions associated with certain livestock has the potential to greatly reduce financial losses. This can be achieved by developing novel diagnostics to quickly identify ill animals alongside the design of novel therapies. To explore this concept further, this review employs Johne's disease, a chronic gastroenteritis condition that affects ruminants, as a case study to exemplify the benefits of rapid diagnostics and effective treatment of chronic disease, with particular regard to the diagnostic and therapeutic potential of phage.
Several countries have shown an increased prevalence of drug resistance in animal production due to the indiscriminate use of antibiotics and antiparasitics in human and veterinary medicine. This article aims to review existing methods using naturally occurring essential oils (EOs) and their isolated compounds (EOCs) as alternatives to antimicrobials and antiparasitic compounds in animal production and, consequently, to avoid resistance. The most-reported mechanism of action of EOs and EOCs was cell membrane damage, which leads to the leakage of cytoplasmic content, increased membrane permeability, inhibition of metabolic and genetic pathways, morphologic changes, antibiofilm effects, and damage to the genetic material of infections. In parasites, anticoccidial effects, reduced motility, growth inhibition, and morphologic changes have been reported. Although these compounds regularly show a similar effect to those promoted by traditional drugs, the elucidation of their mechanisms of action is still scarce. The use of EOs and EOCs can also positively influence crucial parameters in animal production, such as body weight gain, feed conversion rate, and cholesterol reduction, which also positively impact meat quality. The application of EOs and EOCs is enhanced by their association with other natural compounds or even by the association with synthetic chemicals, which has been found to cause synergism in their antimicrobial effect. By reducing the effective therapeutical/prophylactic dose, the chances of off-flavors – the most common issue in EO and EOC application – is greatly mitigated. However, there is very little work on the combination of EOs and EOCs in large in vivo studies. In addition, research must apply the correct methodology to properly understand the observed effects; for example, the use of only high concentrations may mask potential results obtained at lower dosages. Such corrections will also allow the elucidation of finer mechanisms and promote better biotechnologic use of EOs and EOCs. This manuscript presents several information gaps to be filled before the use of EOs and EOCs are fully applicable in animal production.
