Cryptosporidium parvum is recognized as a major cause of diarrheal disease in neonatal bovine calves. In addition, this protozoan parasite has emerged as an important cause of disease in both immunocompromised and immunocompetent humans. Despite years of research, no consistently effective means of prevention or treatment are readily available for cryptosporidiosis in any species. Infection through ingestion of contaminated water has been widely documented; C. parvum was reported to be responsible for the largest waterborne outbreak of infectious disease in US history. In addition to its role as a primary disease agent, C. parvum has potential to initiate or exacerbate other gastrointestinal disorders, such as inflammatory bowel disease. Thus, control of C. parvum infection in both animals and humans remains an important objective. Research in our laboratory has focused on understanding mechanisms of resistance to C. parvum. We have demonstrated that acquisition of intestinal flora increases resistance to C. parvum. Substances present in the intestinal mucosa of adult animals can transfer resistance when fed to susceptible infants. Both expression of intestinal enzymes and rate of proliferation of epithelial cells may be altered following C. parvum infection. These and other changes may have profound effects on host resistance to C. parvum.

American canine hepatozoonosis is an emerging, tick-transmitted infection of domestic dogs caused by a recently recognized species of apicomplexan parasite, Hepatozoon americanum. The known definitive host of the protozoan is the Gulf Coast tick, Amblyomma maculatum. Presently recognized intermediate hosts include the domestic dog and the coyote, Canis latrans. Laboratory-reared larval or nymphal A. maculatum can be infected readily by feeding to repletion on a parasitemic intermediate host; sporogony requires 35–40 days. Transmission of infection to the dog has been produced experimentally by oral administration of mature oocysts or oocyst-containing ticks. Canine disease follows experimental exposure in 4–6 weeks and is characterized by systemic illness, extreme neutrophilic leukocytosis, muscle and bone pain, and proliferation of periosteal bone. Histopathological findings include multifocal skeletal and cardiac myositis associated with escape of mature merozoites from within the host-cell environment. There is also rapid onset of periosteal activation and osteogenesis and, less frequently, glomerulopathy and amyloidosis. Sequential stages of development of H. americanum in both the dog and the tick have been elucidated. Gamonts potentially infectious to ticks have been observed in peripheral blood leukocytes of the dog in as few as 28 days after exposure to oocysts. Young coyotes experimentally exposed to a canine strain of H. americanum acquired disease indistinguishable from that of similarly exposed young dogs.

Levels and seasonal patterns of parasite challenge to livestock are likely to be affected by climate change, through direct effects on life cycle stages outside the definitive host and through alterations in management that affect exposure and susceptibility. Net effects and options for adapting to them will depend very strongly on details of the system under consideration. This short paper is not a comprehensive review of climate change effects on parasites, but rather seeks to identify key areas in which detail is important and arguably under-recognized in supporting farmer adaptation. I argue that useful predictions should take fuller account of system-specific properties that influence disease emergence, and not just the effects of climatic variables on parasite biology. At the same time, excessive complexity is ill-suited to useful farm-level decision support. Dealing effectively with the ‘devil of detail’ in this area will depend on finding the right balance, and will determine our success in applying science to climate change adaptation by farmers.

Cannabis is used in the treatment of several human conditions; however, its use is still less explored in veterinary medicine. This systematic review aims to summarize the evidence of efficacy and safety of the use of cannabis for the treatment of animal disease. A literature search was performed for studies published until 16 March 2021 in five databases. Randomized clinical trials (RCTs) that reported the efficacy or safety of cannabis in the treatment of animal disease were included. The RoB 2 Tool was used to assess the risk of bias. A total of 2427 records were identified, of which six studies fully met the eligibility criteria. RCTs were conducted in dogs with osteoarthritis (n = 4), with epilepsy (n = 1), and with behavioral disorders (n = 1). All studies used cannabidiol (CBD) oil in monotherapy or in combination with other drugs. Studies used CBD at 2 or 2.5 mg kg−1 twice daily (n = 4), orally (n = 5), during 4 or 6 weeks (n = 3), and compared CBD with placebo (n = 5). CBD significantly reduced pain and increased activity in dogs with osteoarthritis (n = 3). Moreover, CBD significantly reduced the frequency of seizures in dogs with epilepsy (n = 1) and the aggressive behavior of dogs (n = 1). Although promising results were identified, studies were heterogeneous and presented risks of bias that required caution in the interpretation of findings. Therefore, there was some evidence to support the use of CBD in dogs with osteoarthritis to reduce pain and increased activity, but limited evidence against epilepsy and behavioral problems. In addition, CBD was well tolerated with mild adverse effects. More RCTs with high quality of evidence are needed, including greater numbers of animal subjects, additional species, and clear readout measures to confirm these findings.

Sepsis is a complex clinical syndrome triggered by an inflammatory host response to an infection. It is usually complicated to detect and diagnose, and has severe consequences in human and veterinary health, especially when treatment is not started early. Therefore, efforts to detect sepsis accurately are needed. In addition, its proper diagnosis could reduce the misuse of antibiotics, which is essential fighting against antimicrobial resistance. This case is a particular issue in farm animals, as antibiotics have been traditionally given massively, but now they are becoming increasingly restricted. When sepsis is suspected in animals, the most frequently used biomarkers are acute phase proteins such as C-reactive protein, serum amyloid A and haptoglobin, but their concentrations can increase in other inflammatory conditions. In human patients, the most promising biomarkers to detect sepsis are currently procalcitonin and presepsin, and there is a wide range of other biomarkers under study. However, there is little information on the application of these biomarkers in veterinary species. This review aims to describe the general concepts of sepsis and the current knowledge about the biomarkers of sepsis in pigs, horses, and cattle and to discuss possible advances in the field.

The clinical syndrome of bovine respiratory disease (BRD) continues to be a major challenge in bovine production systems. We are challenged by our ability to predict morbidity in groups of cattle, our ability to accurately diagnose and provide a prognosis for individual cases, and our ability to evaluate the results of preventive and therapeutic interventions in the field when production system data are the sole basis for analysis. However, we are fortunate to have perhaps the highest quantity and quality of negative-controlled, prospective, randomized, and masked clinical trial data for any disease in veterinary medicine. It is nevertheless important to recognize that case definitions in these studies may not be consistent or necessarily externally relevant, and that production data in these studies are often missing.

The benefits of using plant-based oral vaccines are discussed. Transgenic maize expressing an antigen of transmissible gastroenteritis virus (TGEV) is reported as a model to demonstrate efficacy. Young pigs that were fed the TGEV corn orally were protected against challenge with virulent TGEV. Additional parameters important in providing a reliable and consistent supply of plant-based vaccines are discussed. Finally, vaccines developed in maize are evaluated for their potential to contaminate either the food supply or the environment.

Vitamin D (VD) has been reported to play multiple and significant roles in improving pig health via modulating calcium and phosphorus homeostasis, skeletal muscle development and the immune system. Apart from food, photochemical action of 7-dehydrocholesterol in the skin is the main source of this molecule for pigs. The VD from dietary intake or photosynthesized via skin can be absorbed into the liver for hydroxylation, and further hydroxylated into the hormone form of VD (1,25-dihydroxyvitamin D3 or 1,25(OH)2D3) in the kidney. As a sterol hormone, 1,25(OH)2D3 is able to bind with the VD receptor (VDR), and this ligand-receptor complex (VDR/retinoic X receptor) translocates from the cytoplasm into the nucleus to regulate gene expression, thus modulating metabolism. In this review, we summarized the recent studies regarding the non-skeletal health benefits of VD for pigs, and focused on the recent advances in the cellular and molecular mechanisms of VD that affects the immune system and reproductive health. This review provides a reference for future research and application of VD in pigs.

Dietary fiber (DF) is receiving increasing attention, and its importance in pig nutrition is now acknowledged. Although DF for pigs was frowned upon for a long time because of reductions in energy intake and digestibility of other nutrients, it has become clear that feeding DF to pigs can affect their well-being and health. This review aims to summarize the state of knowledge of studies on DF in pigs, with an emphasis on the underlying mode of action, by considering research using DF in sows as well as suckling and weaned piglets, and fattening pigs. These studies indicate that DF can benefit the digestive tracts and the health of pigs, if certain conditions or restrictions are considered, such as concentration in the feed and fermentability. Besides the chemical composition and the impact on energy and nutrient digestibility, it is also necessary to evaluate the possible physical and physiologic effects on intestinal function and intestinal microbiota, to better understand the relation of DF to animal health and welfare. Future research should be designed to provide a better mechanistic understanding of the physiologic effects of DF in pigs.

Inflammation is a process consisting of a complex of cytological and chemical reactions which occur in and around affected blood vessels and adjacent tissues in response to an injury caused by a physical, chemical or biological insult. Much work has been performed in the past several years investigating inducible nitric oxide synthase (NOS, EC 1.14.13.39) and nitric oxide in inflammation. This has resulted in a rapid increase in knowledge about iNOS and nitric oxide. Nitric oxide formation from inducible NOS is regulated by numerous inflammatory mediators, often with contradictory effects, depending upon the type and duration of the inflammatory insult. Equine medicine appears to have benefited the most from the increased interest in this small, inflammatory mediator. Most of the information on nitric oxide in traditional veterinary species has been produced using models or naturally occurring inflammatory diseases of this species.

The heritability estimates for resistance and/or susceptibility to bovine respiratory disease (BRD) are small, suggesting response to direct selection will be slow. The number of mammalian genetic markers associated with resistance to specific pathogens or improved immunity is increasing and will provide additional information for developing selection criteria for producing animals with an innate resistance to BRD. Environmental and management factors play significant roles in the prevalence of BRD and must be considered in a holistic approach to reducing BRD. Although no single solution for preventing BRD is likely to be discovered in the immediate future, the long-term outlook appears very promising.

A systematic review and network meta-analysis were conducted to assess the relative efficacy of antimicrobial therapy for clinical mastitis in lactating dairy cattle. Controlled trials in lactating dairy cattle with natural disease exposure were eligible if they compared an antimicrobial treatment to a non-treated control, placebo, or a different antimicrobial, for the treatment of clinical mastitis, and assessed clinical or bacteriologic cure. Potential for bias was assessed using a modified Cochrane Risk of Bias 2.0 tool. From 14775 initially identified records, 54 trials were assessed as eligible. Networks were established for bacteriologic cure by bacterial species group, and clinical cure. Disparate networks among bacteriologic cures precluded meta-analysis. Network meta-analysis was conducted for trials assessing clinical cure, but lack of precision of point estimates resulted in wide credibility intervals for all treatments, with no definitive conclusions regarding relative efficacy. Consideration of network geometry can inform future research to increase the utility of current and previous work. Replication of intervention arms and consideration of connection to existing networks would improve the future ability to determine relative efficacy. Challenges in the evaluation of bias in primary research stemmed from a lack of reporting. Consideration of reporting guidelines would also improve the utility of future research.

Castration of male piglets in the United States is conducted without analgesics because no Food and Drug Administration (FDA) approved products are labeled for pain control in swine. The absence of approved products is primarily due to a wide variation in how pain is measured in suckling piglets and the lack of validated pain-specific outcomes individually indistinct from other biological responses, such as general stress or inflammation responses with cortisol. Simply put, to measure pain mitigation, measurement of pain must be specific, quantifiable, and defined. Therefore, given the need for mitigating castration pain, a consortium of researchers, veterinarians, industry, and regulatory agencies was formed to identify potential animal-based outcomes and develop a methodology, based on the known scientific research, to measure pain and the efficacy of mitigation strategies. The outcome-based measures included physiological, neuroendocrine, behavioral, and production parameters. Ultimately, this consortium aims to provide a validated multimodal methodology to demonstrate analgesic drug efficacy for piglet castration.

Measurable outcomes were selected based on published studies suggesting their validity, reliability, and sensitivity for the direct or indirect measurement of pain associated with surgical castration in piglets. Outcomes to be considered are observation of pain behaviors (i.e. ethogram defined behaviors and piglet grimace scale), gait parameters measured with a pressure mat, infrared thermography of skin temperature of the cranium and periphery of the eye, and blood biomarkers. Other measures include body weight and mortality rate.

This standardized measurement of the outcome variable's primary goal is to facilitate consistency and rigor by developing a research methodology utilizing endpoints that are well-defined and reliably measure pain in piglets. The resulting methodology will facilitate and guide the evaluation of the effectiveness of comprehensive analgesic interventions for 3- to 5-day-old piglets following surgical castration.

The costs of bovine respiratory disease (BRD) to the beef producer can be estimated by identifying and summing the direct and indirect costs associated with the disease. The major direct costs are attributable to the cost of the feeder, production costs and carcass disposal. The indirect costs are mainly associated with infrastructure and labour.

Increased antimicrobial resistance in bovine respiratory bacterial pathogens poses a threat to the effective control and prevention of bovine respiratory disease (BRD). As part of continued efforts to develop antimicrobial alternatives to mitigate BRD, the microbial community residing within the respiratory tract of feedlot cattle has been increasingly studied using next-generation sequencing technologies. The mucosal surfaces of upper and lower respiratory tracts of cattle are colonized by a diverse and dynamic microbiota encompassing commensal, symbiotic, and pathogenic bacteria. While a direct causal relationship between respiratory microbiota and the development of BRD in feedlot cattle has not been fully elucidated, increasing evidence suggests that the microbiota contributes to respiratory health by providing colonization resistance against pathogens and maintaining homeostasis. Certain management practices such as weaning, transportation, feed transition, and antibiotic application can disrupt the respiratory microbiota, potentially altering pathogen colonization. Microbiota-based approaches, including bacterial therapeutics that target restoring the normal respiratory microbiota, may provide new methods for mitigating BRD in feedlot cattle in place of antibiotics. In addition, the distinct bacterial respiratory microbial communities observed in BRD-affected and healthy feedlot cattle may allow for future application of microbiota-based techniques used in the diagnosis of BRD.

With more than half of the global population living in cities, the urban areas are also teeming with animals, including peridomestic wildlife, pets, and livestock. Urban animals may carry zoonotic pathogens, and crowded conditions in cities can increase the risk for the human population. We used a systematic approach to screen two publication databases as well as gray literature, and quantified the studies conducted on zoonoses in urban animals with respect to the geographic distribution, the host animal and pathogens. Out of 876 references found, 93 were included into final data extraction. Few studies were from the rapidly expanding cities in low- and middle-income countries where urban livestock-keeping is far more prominent than in high-income countries. Most studies were performed in peridomestic wildlife and pets, less in livestock. The most common category of pathogens studied were gastrointestinal parasites followed by gastrointestinal bacteria, whereas studies on some other zoonoses internationally recognized as critical for public health were few or absent. In conclusion, to mitigate the risks of emergence of zoonoses from urban animals this review highlights the research gaps on zoonoses, particularly in livestock in rapidly growing tropical cities and a more comprehensive inclusion of pathogens prioritized by WHO and OIE.

Swine vesicular disease is a highly contagious disease of pigs that is caused by an enterovirus of the family Picornaviridae. The virus is a relatively recent derivative of the human coxsackievirus B5, with which it has high molecular and antigenic homology. The disease is not severe, and affected animals usually show moderate general weakening and slight weight loss that is recovered in few days, as well as vesicular lesions in the mucosa of the mouth and nose and in the interdigital spaces of the feet. However, the similarity of these lesions to those caused by foot-and-mouth disease virus has led to the inclusion of this virus in list A of the Office International des Epizooties. The disease has been eradicated in the European Union except in Italy, where it is considered endemic in the south. Nevertheless, as occasional outbreaks still appear and must be eliminated rapidly, European countries are on the alert and farms are monitored routinely for the presence of the virus. This circumstance has led to a considerable effort to study the pathology of the disease and the molecular biology and antigenicity of the virus, and to the development of optimized methods for the diagnosis of the infection.

Recent technological advances has led to the generation, storage, and sharing of colossal sets of information (‘big data’), and the expansion of ‘omics’ in science. To date, genomics/metagenomics, transcriptomics, proteomics, and metabolomics are arguably the most ground breaking approaches in food and public safety. Here we review some of the recent studies of foodborne pathogens (Campylobacter spp., Salmonella spp., and Escherichia coli) in poultry using big data. Genomic/metagenomic approaches have reveal the importance of the gut microbiota in health and disease. They have also been used to identify, monitor, and understand the epidemiology of antibiotic-resistance mechanisms and provide concrete evidence about the role of poultry in human infections. Transcriptomics studies have increased our understanding of the pathophysiology and immunopathology of foodborne pathogens in poultry and have led to the identification of host-resistance mechanisms. Proteomic/metabolomic approaches have aided in identifying biomarkers and the rapid detection of low levels of foodborne pathogens. Overall, ‘omics' approaches complement each other and may provide, at least in part, a solution to our current food-safety issues by facilitating the development of new rapid diagnostics, therapeutic drugs, and vaccines to control foodborne pathogens in poultry. However, at this time most ‘omics' approaches still remain underutilized due to their high cost and the high level of technical skills required.

Endothelial cells were once viewed as relatively inert cells lining the vasculature. They are now recognized as active and responsive regulators of coagulation, platelet adhesion, fluid homeostasis, wound healing, leukocyte extravasation and vascular tone. Endothelial cells play a key role in the host response to infectious agents by regulating leukocyte trafficking, producing inflammatory cytokines and presenting antigen in association with major histocompatibility class II (MHC II) molecules. A number of infectious agents have a tropism for endothelial cells. Infection of endothelial cells can promote thrombosis, vascular leakage, and increased adherence and emigration of leukocytes. Furthermore, activation of a systemic inflammatory response, in the absence of direct endothelial cell infection, can also lead to endothelial cell dysfunction. The purpose of this review is to highlight the interactions between endothelial cells and infectious or inflammatory agents that contribute to coagulation disturbances, vasculitis and edema. A select group of viral and bacterial pathogens will be used as examples to demonstrate how endothelial cell dysfunction contributes to the pathogenesis of infectious and inflammatory disorders.

Wild birds have been the focus of a great deal of research investigating the epidemiology of zoonotic bacteria and antimicrobial resistance in the environment. While enteric pathogens (e.g. Campylobacter, Salmonella, and E. coli O157:H7) and antimicrobial resistant bacteria of public health importance have been isolated from a wide variety of wild bird species, there is a considerable variation in the measured prevalence of a given microorganism from different studies. This variation may often reflect differences in certain ecological and biological factors such as feeding habits and immune status. Variation in prevalence estimates may also reflect differences in sample collection and processing methods, along with a host of epidemiological inputs related to overall study design. Because the generalizability and comparability of prevalence estimates in the wild bird literature are constrained by their methodological and epidemiological underpinnings, understanding them is crucial to the accurate interpretation of prevalence estimates. The main purpose of this review is to examine methodological and epidemiological inputs to prevalence estimates in the wild bird literature that have a major bearing on their generalizability and comparability. The inputs examined here include sample type, microbiological methods, study design, bias, sample size, definitions of prevalence outcomes and parameters, and control of clustering. The issues raised in this review suggest, among other things, that future prevalence studies of wild birds should avoid opportunistic sampling when possible, as this places significant limitations on the generalizability of prevalence data.