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Simple Summary: The precise assessment of pain remains a critical concern in ensuring the welfare of companion animals. Consequently, innovative technologies such as infrared thermography have been investigated. The aim of this study was to evaluate the facial thermal nociceptive response elicited by the administration of cannabidiol (CBD) alone and in combination with meloxicam in female dogs undergoing elective ovariohysterectomy under isoflurane anesthesia. Sixty-four bitches from different breeds were selected and randomly assigned into four groups according to the analgesic treatment. The groups were as follows: G1: Placebo group (n = 16). G2: Group premedicated with meloxicam at 0.2 mg kg−1 IV (n = 16). Postoperatively, this drug was used at 0.1 mg kg−1 every 24 h. G3: Group treated with CBD (n = 16) at a dose of 2 mg kg−1 orally every 12 h. G4: Group medicated with the combination of both treatments (n = 16). The findings revealed that the superficial temperature of the lacrimal gland, upper eyelid and lower eyelid was significantly lower in animals receiving analgesic treatments with meloxicam, CBD or a combination of the two when compared to the placebo group. This reduction correlated with physiological parameters such as heart rate and respiratory rate. Therefore, based on the superficial thermal response, it can be concluded that the use of CBD, either alone or in combination with meloxicam, exhibited comparable analgesic efficacy, effectively modulating nociceptive cardiorespiratory and hemodynamic autonomic responses, with no significant differences in facial thermal patterns observed between treatments. Pain management requires the identification of certain indicators to recognize pain. Various tools have been suggested to achieve an objective evaluation, including infrared thermography (IRT). The objective of this study was to assess the facial thermal nociceptive response produced by the use of cannabidiol (CBD) alone and in combination with meloxicam in female dogs undergoing elective ovariohysterectomy anesthetized with isoflurane. Sixty-four female dogs of different breeds were randomly distributed into four study groups according to the treatment received. G1: Placebo group (n = 16); G2: Group receiving intravenous meloxicam as premedication (0.2 mg Kg−1) and every 24 h postoperatively 0.1 mg Kg−1 (n = 16); G3: Group treated with CBD (n = 16) at a dose of 2 mg kg−1 orally every 12 h; and G4: Group medicated with the combination of both treatments (n = 16). All treatments were administered for 48 h postoperatively. After the anesthetic surgical procedure, radiometric images were captured using IRT and physiological parameters during the events EBasal, E30min, E1h, E2h, E3h, E4h, E8h, E12h, E24h and E48h. Overall, it was found that the high, medium and low temperatures of the thermal windows of the eye, upper eyelid and lower eyelid, as well as the average temperature of the lacrimal gland in G1 between events, were significantly lower at E30min, E1h and E2h compared to EBasal (p = 0.01). Among treatments, a significantly higher temperature was observed in groups G2, G3 and G4 compared to G1 (p = 0.001) in the thermal windows of the upper eyelid, lower eyelid, lacrimal gland and ocular areas. Regarding physiological parameters, heart rate (HR) was higher in G1 compared to the animals in G2, G3 and G4 (p = 0.03). The respiratory rate (RR) was significantly lower in all four study groups during the postoperative events compared to their respective EBasal (p < 0.05), while among treatments, G2, G3 and G4 had a lower RR compared to G1 (p = 0.03). Mild hypothermia was observed in all study groups at E30min and E1h compared to EBasal (p = 0.001). No significant correlation was found between the temperatures of the assessed thermal regions and the physiological traits. In conclusion, CBD, whether administered alone or in combination with meloxicam, demonstrated comparable analgesic efficacy, which could control nociceptive cardiorespiratory and hemodynamic autonomic responses, as there were no significant changes in the facial thermal response between treatments G2, G3 and G4. [ABSTRACT FROM AUTHOR]

Simple Summary: In humans, it is suggested that facial expressions reflect the emotional state of the individual but can also serve as a communicative signal. Chimpanzees, orangutans, and gorillas are the species closest to humans. Therefore, studying if nonhuman primate facial expression changes according to the affective state is relevant for research focused on the emotional responses of animals. The present review aims to discuss the neural correlates and anatomical components of emotional facial expression in great apes. It will focus on the use of Facial Action Coding Systems (FACSs) and the movements of the facial muscles (AUs) of chimpanzees, orangutans, and gorillas and their possible association with the affective state of great apes. The Facial Action Coding System (FACS) is an anatomically based system to study facial expression in humans. Currently, it is recognized that nonhuman animals, particularly nonhuman primates, have an extensive facial ethogram that changes according to the context and affective state. The facial expression of great apes, the closest species to humans, has been studied using the ChimpFACS and OrangFACS as reliable tools to code facial expressions. However, although the FACS does not infer animal emotions, making additional evaluations and associating the facial changes with other parameters could contribute to understanding the facial expressions of nonhuman primates during positive or negative emotions. The present review aims to discuss the neural correlates and anatomical components of emotional facial expression in great apes. It will focus on the use of Facial Action Coding Systems (FACSs) and the movements of the facial muscles (AUs) of chimpanzees, orangutans, and gorillas and their possible association with the affective state of great apes. [ABSTRACT FROM AUTHOR]

Simple Summary: This review aims to discuss the hypothalamic control of hyperthermia in livestock, including the main physiological and behavioral changes that animals adopt to maintain their thermal stability. This review analyzes the main changes that can be observed in livestock when exposed to intense heat. Vasodilation, sweating, and behavioral modifications (e.g., standing posture, shade seeking, feed intake, among others) are the results of neuronal projections from peripheral thermoreceptors to the preoptic area of the hypothalamus and effector neurons. Understanding these mechanisms can help to visualize their effect to restore thermal neutrality in livestock. Hyperthermia elicits several physiological and behavioral responses in livestock to restore thermal neutrality. Among these responses, vasodilation and sweating help to reduce core body temperature by increasing heat dissipation by radiation and evaporation. Thermoregulatory behaviors such as increasing standing time, reducing feed intake, shade-seeking, and limiting locomotor activity also increase heat loss. These mechanisms are elicited by the connection between peripheral thermoreceptors and cerebral centers, such as the preoptic area of the hypothalamus. Considering the importance of this thermoregulatory pathway, this review aims to discuss the hypothalamic control of hyperthermia in livestock, including the main physiological and behavioral changes that animals adopt to maintain their thermal stability. [ABSTRACT FROM AUTHOR]

Simple Summary: Buffaloes are typically raised in tropical, flood-prone zones, thus exposed to conditions conducive to the growth of disease-causing pathogens and their vectors. They generally share the habitat with cattle, representing sanitary problems because viral agents can transmit between both species; many are zoonotic and public health concerns. The mobilization and introduction of buffaloes and their biological products from one continent or country to another pose a risk of spreading viral diseases considered exotic in certain regions. This underscores the critical need for rigorous epidemiological surveillance of infectious diseases within buffalo herds. Additionally, it highlights the potential implications and risks these diseases pose to other livestock species and public health in newly inhabited regions. This review discusses the more reported viral diseases in water buffaloes, their characteristics, epidemiology, disease behavior, and interaction with other species, vectors, and pathogens. The epidemiology of buffalo viral diseases must be continuously reconsidered and updated to obtain better prevention and control programs. The water buffalo (Bubalus bubalis) has great adaptability to rustic environments and more variable conditions than cattle, who generally share the habitat. Diseases carried by buffaloes are relatively unknown and ignored and could be transmissible; an imbalance occurs between pathogens, environment, and susceptible hosts, generating a severe animal health problem. Also relevant is the effect of climate change on the populations of vectors that transmit viral diseases. The discovery of new virus variants that can pass from bovine (Bos) to buffalo or vice versa or to humans has highlighted the relevance of viruses crossing the host barrier. This review discusses the clinical viral diseases most reported in the water buffalo, characteristics, epidemiology, and recent findings about disease behavior, interaction with other species, the host, vectors, and pathogens. Diseases reviewed include Foot and Mouth Disease, Rinderpest, Malignant Catarrhal Fever, Infectious Bovine Rhinotracheitis, Bovine Viral Diarrhea, and Rabies. Also, vector-borne diseases include Lumpy Skin Disease, Ephemeral Fever, and Blue Tongue. The review also considers emerging viruses such as Buffalo Pox and Schmallenberg and, finally, other viruses such as papillomatosis. The knowledge and epidemiology of buffalo viral diseases must be constantly reconsidered and updated for adequate prevention and control programs. [ABSTRACT FROM AUTHOR]

Simple Summary: This review aims to analyze the application of IRT in the evaluation of gait, the recognition of lameness, the evaluation of the effectiveness of the therapy, and the superficial thermal response in veterinary medicine during the rehabilitation of patients. Due to the ability of infrared thermography to detect changes in the local temperature of several body regions, this tool might help identify and monitor the progress of musculoskeletal injuries in veterinary patients. Infrared Thermography (IRT) has become an assistance tool in medicine and is used to noninvasively evaluate heat elimination during and after inflammatory processes or during the recovery period. However, its application in veterinary patients undergoing physiotherapy is a field that requires deep research. This review aims to analyze the application of IRT in the monitoring of animal physiotherapy, using the thermal changes that are present in patients undergoing gait or lameness issues (e.g., inflammation, pain, increased local temperature) as a neurobiological basis. Rehabilitation techniques such as acupuncture, physical therapies, thermotherapy, photo-biomodulation, and electrostimulation have been reported to have an anti-inflammatory effect that decreases the amount of local heat production, which is heat that can be recorded with IRT. Therefore, IRT could be used as a complementary tool to evaluate the effectiveness of the therapy, and it is suggested that further studies evaluate the accuracy, sensibility, and sensitivity of IRT. [ABSTRACT FROM AUTHOR]

Simple Summary: Due to anatomical differences in the skull of the water buffalo (Bubalus bubalis), the currently applied mechanical stunning methods in cattle (genus Bos) have shown to be ineffective in buffaloes by not damaging vital cerebral structures associated with consciousness. The present review analyzes these anatomical particularities of water buffaloes to discuss the importance of selecting a stunning method suitable for the species to avoid pain and suffering. Potential pain-related processes such as hyperalgesia and sensitization are also addressed. In addition, the signs to assess stun quality and return to consciousness are discussed to elucidate the importance of recognizing these indicators and prevent physiological consequences and affectation to water buffaloes' welfare and quality of death. The slaughter process in livestock is considered a stressor where the transport and handling of animals, as well as the selected stunning and bleeding methods, can cause acute pain, distress, and suffering. In water buffaloes, although stunning is known to be performed before bleeding to induce unconsciousness, no emphasis is made on the nociceptive events during this process. Particularly, current mechanical stunning methods applied to cattle are unsuitable for water buffaloes due to anatomical differences in the skull from other large ruminants. Furthermore, although very high-pressure pneumatic (200–220 psi) may be effective in the frontal position for lighter-weight water buffalos, for heavier animals, it is less likely to be effective. The present review aims: (1) to analyze the anatomical particularities of water buffaloes to discuss the importance of selecting a stunning method suitable for buffaloes, and (2) to revise the potential pain-related consequences, such as hyperalgesia and sensitization, and the signs to assess the stun quality and death to comprehend the relevance of a proper technique according to the species. [ABSTRACT FROM AUTHOR]

Simple Summary: Although ruminant newborns are a precocial species, they are susceptible to hypothermia and neonatal mortality during the first hours of life due to intrinsic and extrinsic factors that challenge their thermostability. Several mechanisms are activated when the organism perceives a temperature decrease, such as vasoconstriction, shivering, and non-shivering thermogenesis. These have been widely studied in lambs, goats, and cattle. However, for water buffalo, a relevant, productive species, the investigation of thermoregulation in the neonate immediately after calving, and of the tools to assess their thermal state, is limited. This review aims to analyze behavioral, morphological, and physiological strategies in newborn water buffaloes facing thermal stressors and discuss the role of infrared thermography in monitoring hypothermic states. Hypothermia is one of the principal causes of perinatal mortality in water buffaloes and can range from 3% to 17.9%. In ruminants, factors affecting hypothermia in newborns may be of intrinsic (e.g., level of neurodevelopment, birth weight, vitality score, amount of brown fat, skin features) or extrinsic origin (e.g., maternal care, environmental conditions, colostrum consumption). When newborn buffaloes are exposed to cold stress, thermoregulatory mechanisms such as peripheral vasoconstriction and shivering and non-shivering thermogenesis are activated to prevent hypothermia. Due to the properties of infrared thermography (IRT), as a technique that detects vasomotor changes triggered by a reduction in body temperature, evaluating the central and peripheral regions in newborn buffaloes is possible. This review aims to analyze behavioral, physiological, and morphological strategies and colostrum consumption as thermal compensation mechanisms in newborn water buffalo to cope with environmental changes affecting thermoneutrality. In addition, the importance of monitoring by IRT to identify hypothermia states will be highlighted. Going deeper into these topics related to the water buffalo is essential because, in recent years, this species has become more popular and is being bred in more geographic areas. [ABSTRACT FROM AUTHOR]

Simple Summary: Current acute pain assessment protocols in domestic animals require the use of a suite of methods to evaluate the multidimensional components of pain. Thermal imaging is a method that assesses the physiological response, via heat production, to a noxious stimulus. This may correlate with the affective experience of acute pain. Since the use of the method as a pain assessment tool is still in its relative infancy and has yet to be fully evaluated empirically, the present review brings together current knowledge on the use of infrared thermography to evaluate acute pain in animals. We also propose future directions in this area of research. Pain assessment in domestic animals has gained importance in recent years due to the recognition of the physiological, behavioral, and endocrine consequences of acute pain on animal production, welfare, and animal model validity. Current approaches to identifying acute pain mainly rely on behavioral-based scales, quantifying pain-related biomarkers, and the use of devices monitoring sympathetic activity. Infrared thermography is an alternative that could be used to correlate the changes in the superficial temperature with other tools and thus be an additional or alternate acute pain assessment marker. Moreover, its non-invasiveness and the objective nature of its readout make it potentially very valuable. However, at the current time, it is not in widespread use as an assessment strategy. The present review discusses scientific evidence for infrared thermography as a tool to evaluate pain, limiting its use to monitor acute pain in pathological processes and invasive procedures, as well as its use for perioperative monitoring in domestic animals. [ABSTRACT FROM AUTHOR]

Simple Summary: Caffeine is a stimulant used in humans and animals to improve newborns' respiratory and neurological responses. The use of caffeine after birth could increase neonate survival. However, due to the immature systems of animals at birth, caffeine use can have different results. This review aims to understand caffeine's effects on respiratory and neurological systems in neonate animal models (rat and mouse pups, goat kids, lambs, and piglets). Caffeine is widely used to improve neonatal health in animals with low vitality. Due to its pharmacokinetics and pharmacodynamics, caffeine stimulates the cardiorespiratory system by antagonism of adenosine receptors and alteration in Ca+2 ion channel activity. Moreover, the availability of intracellular Ca+2 also has positive inotropic effects by increasing heart contractibility and by having a possible positive effect on neonate vitality. Nonetheless, since neonatal enzymatic and tissular systems are immature at birth, there is a controversy about whether caffeine is an effective therapy for newborns. This review aims to analyze the basic concepts of caffeine in neonatal animal models (rat and mouse pups, goat kids, lambs, and piglets), and it will discuss the neuroprotective effect and its physiological actions in reducing apnea in newborns. [ABSTRACT FROM AUTHOR]

Simple Summary: Vitality is a characteristic that in newborn animals demonstrates their vigor and their general state of health (heart rate, respiratory rate, skin color, time that they take to stand up) during the first hours of life. It can be measured by numerical scores based on some scales made for babies and then adapted for various animals. Vitality can be affected by several factors. The objective of this review is to analyze pharmacological and physical therapies used to increase vitality in newborn farm animals, as well as understand the factors affecting their vitality, such as hypoxia, depletion of glycogen, birth weight, dystocia, neurodevelopment, hypothermia, and finally, the physiological mechanism to achieve thermostability. It is essential to evaluate vitality in newborns because it can contribute to implementing interventions to reduce newborn mortality. Vitality is the vigor newborn animals exhibit during the first hours of life. It can be assessed by a numerical score, in which variables, such as heart rate, respiratory rate, mucous membranes' coloration, time the offspring took to stand up, and meconium staining, are monitored. Vitality can be affected by several factors, and therapies are used to increase it. This manuscript aims to review and analyze pharmacological and physical therapies used to increase vitality in newborn farm animals, as well as to understand the factors affecting this vitality, such as hypoxia, depletion of glycogen, birth weight, dystocia, neurodevelopment, hypothermia, and finally, the physiological mechanism to achieve thermostability. It has been concluded that assessing vitality immediately after birth is essential to determine the newborn's health and identify those that need medical intervention to minimize the deleterious effect of intrapartum asphyxia. Vitality assessment should be conducted by trained personnel and adequate equipment. Evaluating vitality could reduce long-term neonatal morbidity and mortality in domestic animals, even if it is sometimes difficult with the current organization of some farms. This review highlights the importance of increasing the number of stock people during the expected days of parturitions to reduce long-term neonatal morbidity and mortality, and thus, improve the farm's performance. [ABSTRACT FROM AUTHOR]

Simple Summary: Euthanasia is a common procedure performed by veterinary professionals, which carries important ethical, moral, and legal challenges. In the case of dogs with chronic and terminal illnesses, the decision is highly influenced by owner-related perspectives, financial constraints, caregiver burden, and emotional attachment. Likewise, although the current legal framework in different countries states that euthanasia should be applied as a last alternative in those animals with incurable pain and suffering, the veterinarian must comply with both legal and social responsibilities. The present review explores the ethical and legal implications of euthanasia in canine patients, highlighting the importance of effective communication, ethical knowledge, and consideration of euthanasia as a multimodal resolution. Euthanasia is commonly performed in veterinary medicine to humanely induce the death of an animal when its quality of life is affected by pain or chronic degenerative diseases. The choice of euthanasia is a bilateral decision that represents a challenge for both the veterinarian and the owner of the animal due to the close emotional human–animal bond. Currently, there is legislation that can orient veterinarians concerning euthanasia and the causes that would justify this resolution. However, it is still controversial, and deciding it as the last available resort requires considering it from a medical, legal, and moral perspective. Therefore, this review aims to explore the ethical and legal implications of euthanasia in canine patients. It will analyze the reason that can justify euthanasia in animals with pain or terminal and chronic degenerative diseases, highlighting the importance of effective communication, ethical knowledge, and consideration of euthanasia as a multimodal resolution. [ABSTRACT FROM AUTHOR]

Simple Summary: The present review highlights and examines the importance of animal models in relevant topics concerning current human and animal health. Over the past five years, different animal species have been used to study pandemics, such as the 2019 Coronavirus, diabetes, and obesity. Through murine, primate, porcine, and even aquatic models (e.g., zebrafish), several neurological, behavioral, cardiovascular, and oncological disorders are being understood while developing new therapeutic approaches. Nematodes and arthropods are some of the new alternatives for biomedical science; however, regardless of the species, many animal research studies show the vital role of animal models in advancing biomedical research. Animal research is considered a key element in advance of biomedical science. Although its use is controversial and raises ethical challenges, the contribution of animal models in medicine is essential for understanding the physiopathology and novel treatment alternatives for several animal and human diseases. Current pandemics' pathology, such as the 2019 Coronavirus disease, has been studied in primate, rodent, and porcine models to recognize infection routes and develop therapeutic protocols. Worldwide issues such as diabetes, obesity, neurological disorders, pain, rehabilitation medicine, and surgical techniques require studying the process in different animal species before testing them on humans. Due to their relevance, this article aims to discuss the importance of animal models in diverse lines of biomedical research by analyzing the contributions of the various species utilized in science over the past five years about key topics concerning human and animal health. [ABSTRACT FROM AUTHOR]

Simple Summary: Oxytocin is one of the most important hormones in birth and lactation. Its importance lies in the fact that it is also involved in various bodily functions around parturition and establishing maternal behavior. We aimed to analyze all the facts involving oxytocin regulation and participation in different peripartum situations in domestic mammals. In addition, the authors examined the impact of altering normal plasma oxytocin values on maternal behavior and care, productive parameters, and imprinting. Oxytocin (OXT) is one of the essential hormones in the birth process; however, estradiol, prolactin, cortisol, relaxin, connexin, and prostaglandin are also present. In addition to parturition, the functions in which OXT is also involved in mammals include the induction of maternal behavior, including imprinting and maternal care, social cognition, and affiliative behavior, which can affect allo-parental care. The present article aimed to analyze the role of OXT and the neurophysiologic regulation of this hormone during parturition, how it can promote or impair maternal behavior and bonding, and its importance in lactation in domestic animals. [ABSTRACT FROM AUTHOR]

Simple Summary: Newborns experience a significant thermal change at birth, leading their bodies to adjust and reduce their metabolism to survive. In this study, newborn puppies' weights and their temperatures in different body areas and at different measure times were evaluated to determine if there is a relationship between weight and their ability to reach thermostability. It was observed that there is a positive relationship between the weight of the puppies and their thermoregulatory capacity. Hypothermia, a factor associated with neonatal mortality, can occur immediately after birth as a protective mechanism to prevent hypoxic damage in neonates, or to reduce the metabolic rate to improve the chances of survival in the first hours of life. The heat interchange through the superficial temperature of animals can be evaluated with infrared thermography (IRT). However, to date, there is no information on thermal windows in puppies. This study aimed to evaluate, with the use of IRT, the microcirculatory alterations in 8 different thermal windows identified at 7 different times in 289 newborn puppies assigned to different groups. Three thermograms were taken from four zones of each puppy: the facial, frontal, right lateral, and left lateral regions. Newborn puppies were grouped in 4 quartiles according to their weight: Q1 (126–226 g) n = 73, Q2 (227–330 g) n = 72, Q3 (331–387 g) n = 74, and Q4 (388–452 g) n = 70. A total of 8 thermal windows were considered at 7 evaluation times from Wet at birth until 24 h after birth (AB). Two-way mixed ANOVA within and between subjects' design for each thermal window (eight models) was performed. Results revealed a positive correlation between the puppy's weight and its ability to achieve thermostability in all the evaluated thermal windows. Statistically significant differences (p < 0.0001) between the 4 quartiles (Q1, Q2, Q3, and Q4) were found. The lowest temperatures were recorded when the pups were still wet and the highest at 24 h AB. Thermal windows with the highest temperatures were abdominal (34.234 ± 0.056 °C), thoracic (33.705 ± 0.049 °C), nasal (30.671 ± 0.110 °C), and upper left palpebral (34.066 ± 0.052 °C), while the lowest were thoracic limb brachial biceps (27.534 ± 0.051 °C), thoracic limb elbow (27.141 ± 0.049 °C), thoracic limb metacarpal (27.024 ± 0.062 °C), and femoral pelvic limb (27.654 ± 0.055 °C). Assessing the thermal response in newborn puppies can help identify drastic temperature reductions or deficient thermoregulatory compensation during the first hours of life, preventing the consequences of hypothermia. [ABSTRACT FROM AUTHOR]

Simple Summary: Ensuring the welfare of wildlife under human care requires tools to monitor their health and well-being. Infrared thermography is a non-invasive technique for assessing thermal states that measure the radiation emitted from the skin in distinct anatomical areas, known as thermal windows—anatomical regions with abundant capillaries and arteriovenous anastomosis that facilitate heat exchange with the environment. However, thermal windows for wildlife species have not yet been established due to the different characteristics of their skin, coats, fur, or coloring. This review discusses published information on the usefulness of the ocular, nasal, thoracic, abdominal, and podal anatomical regions as thermal windows for evaluating these animals' thermal responses and health status and monitoring habitat design. Another aspect that must be considered for wildlife under human care is the limitations of distinct species due to differences between animals and critical factors. Future studies should focus on establishing a precise application for each thermal window according to the specific characteristics of distinct animal species. Promoting animal welfare in wildlife species under human care requires the implementation of techniques for continuously monitoring their health. Infrared thermography is a non-invasive tool that uses the radiation emitted from the skin of animals to assess their thermal state. However, there are no established thermal windows in wildlife species because factors such as the thickness or color of the skin, type/length of coat, or presence of fur can influence the readings taken to obtain objective, sensitive values. Therefore, this review aims to discuss the usefulness and application of the ocular, nasal, thoracic, abdominal, and podal anatomical regions as thermal windows for evaluating zoo animals' thermal response and health status. A literature search of the Web of Science, Science Direct, and PubMed databases was performed to identify relevant studies that used IRT with wild species as a complementary diagnostic tool. Implementing IRT in zoos or conservation centers could also serve as a method for determining and monitoring optimal habitat designs to meet the needs of specific animals. In addition, we analyze the limitations of using IRT with various wildlife species under human care to understand better the differences among animals and the factors that must be considered when using infrared thermography. [ABSTRACT FROM AUTHOR]

Simple Summary: Meconium aspiration syndrome is a pathology that causes hypoxia, acidosis, and neonatal mortality. The mechanisms behind this rely on physiopathology and the interaction of meconium with pulmonary alveolar cells. The inflammatory response, inactivation of surfactant, and processes such as apoptosis or necrosis of alveolar macrophages, epithelial and endothelial cells also participate in this syndrome. In this review, the physiopathology of meconium aspiration syndrome will be discussed in veterinary medicine to understand the inflammatory response and the cellular and biochemical changes at the alveolar level that cause the main outcomes of this pathology. Meconium Aspiration Syndrome is a condition that causes respiratory distress in newborns due to occlusion and airway inflammation, and surfactant inactivation by meconium. This condition has been described in animal species such as canids, sheep, cattle, horses, pigs, and marine mammals. In its pathogenesis, the pulmonary epithelium activates a limited inflammatory response initiated by cytokines causing leukocyte chemotaxis, inhibition of phagocytosis, and pathogen destruction. Likewise, cytokines release participates in the apoptosis processes of pneumocytes due to the interaction of angiotensin with cytokines and the caspase pathway. Due to these reactions, the prevalent signs are lung injury, hypoxia, acidosis, and pneumonia with susceptibility to infection. Given the importance of the pathophysiological mechanism of meconium aspiration syndrome, this review aims to discuss the relevance of the syndrome in veterinary medicine. The inflammatory processes caused by meconium aspiration in animal models will be analyzed, and the cellular apoptosis and biochemical processes of pulmonary surfactant inactivation will be discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: Infrared thermography is a tool that measures changes in the surface temperature of the skin and has been used in companion animals to determine their health state and to diagnose inflammatory processes, neoplasia, pain, or neuropathies. Body regions such as the face, body, or hind/forelimbs are commonly used for thermography in dogs and cats. However, since there is disagreement about the differences in temperature recorded using this tool, this article analyzes the usefulness of IRT in companion animals (pets) as a complementary diagnostic method for evaluating thermal and circulatory changes. It analyzes the recent scientific evidence on the use of facial, body, and appendicular thermal windows in dogs and cats under different clinical conditions. Infrared thermography (IRT) has been proposed as a method for clinical research to detect local inflammatory processes, wounds, neoplasms, pain, and neuropathies. However, evidence of the effectiveness of the thermal windows used in dogs and cats is discrepant. This review aims to analyze and discuss the usefulness of IRT in diverse body regions in household animals (pets) related to recent scientific evidence on the use of the facial, body, and appendicular thermal windows. IRT is a diagnostic method that evaluates thermal and circulatory changes under different clinical conditions. For the face, structures such as the lacrimal caruncle, ocular area, and pinna are sensitive to assessments of stress degrees, but only the ocular window has been validated in felines. The usefulness of body and appendicular thermal windows has not been conclusively demonstrated because evidence indicates that biological and environmental factors may strongly influence thermal responses in those body regions. The above has led to proposals to evaluate specific muscles that receive high circulation, such as the bicepsfemoris and gracilis. The neck area, perivulvar, and perianal regions may also prove to be useful thermal windows, but their degree of statistical reliability must be established. In conclusion, IRT is a non-invasive technique that can be used to diagnose inflammatory and neoplastic conditions early. However, additional research is required to establish the sensitivity and specificity of these thermal windows and validate their clinical use in dogs and cats. [ABSTRACT FROM AUTHOR]

Simple Summary: In this review, recent discoveries regarding transient receptor potential are discussed and analyzed to comprehend their role in the thermoregulatory mechanisms of animals. Understanding how these receptors are activated and the pathways through which they recognize specific thermal sensations (such as cold, warm, and hot temperatures) will help researchers verify their participation in inflammatory and pathological processes. Research on transient receptor potential and their functions is ongoing, and many current studies are designed to develop therapeutic approaches that will act directly on these receptors to improve the quality of life of non-human animals. This review presents and analyzes recent scientific findings on the structure, physiology, and neurotransmission mechanisms of transient receptor potential (TRP) and their function in the thermoregulation of mammals. The aim is to better understand the functionality of these receptors and their role in maintaining the temperature of animals, or those susceptible to thermal stress. The majority of peripheral receptors are TRP cation channels formed from transmembrane proteins that function as transductors through changes in the membrane potential. TRP are classified into seven families and two groups. The data gathered for this review include controversial aspects because we do not fully know the mechanisms that operate the opening and closing of the TRP gates. Deductions, however, suggest the intervention of mechanisms related to G protein-coupled receptors, dephosphorylation, and ligands. Several questions emerge from the review as well. For example, the future uses of these data for controlling thermoregulatory disorders and the invitation to researchers to conduct more extensive studies to broaden our understanding of these mechanisms and achieve substantial advances in controlling fever, hyperthermia, and hypothermia. [ABSTRACT FROM AUTHOR]

Simple Summary: Animals adopt several strategies to regulate their body temperature by promoting heat loss or gain in hot and cold environments, respectively. This mechanism of heat loss or production is performed in thermal windows. A thermal window is a structure where many blood capillaries facilitate thermal exchange in this region. The presence of feathers, hair, or glabrous (hairless) skin and their structural characteristics greatly influence each species' capacity to maintain thermal comfort. This factor needs to be considered when implementing new monitoring or measuring techniques such as infrared thermography since interpretations may vary due to the presence or absence of these structures. It is essential to recognize the effects of glabrous skin, hair, and feathers on thermoregulation to identify species-specific thermal windows that allow accurate evaluations of the thermal state of domestic animals. The objective of this review is to describe and analyze the effect of feathers, hair, and glabrous (hairless) skin on the thermoregulation of domestic and endotherm animals, especially concerning the uses and scope of infrared thermography (IRT), scientific findings on heat and cold stress, and differences among species of domestic animals. Clinical medicine considers thermoregulation a mechanism that allows animals to adapt to varying thermal environmental conditions, a process in which the presence of feathers, hair, or glabrous skin influences heat loss or heat retention, respectively, under hot and cold environmental conditions. Evaluating body temperature provides vital information on an individual's physiological state and health status since variations in euthermia maintenance in vertebrates reflect a significant cellular metabolism deviation that needs to be assessed and quantified. IRT is a non-invasive tool for evaluating thermal responses under thermal stress conditions in animals, where the presence or absence of feathers, hair, and glabrous skin can affect readings and the differences detected. Therefore, anatomical regions, the characteristics of feathers, hair, glabrous skin such as structure, length, color, and extension, and strategies for dissipating or retaining heat together constitute a broad area of opportunity for future research into the phenomena of dermal thermoregulation in domestic species. [ABSTRACT FROM AUTHOR]

Simple Summary: Laboratory animals are fundamental in biomedical science and monitoring their health and metabolic processes is essential to ensure their welfare and the quality of the research conducted. Infrared thermography (IRT) is a tool that can assess pathological or stressful states by measuring changes in the amount of heat that bodies dissipate. To date, some thermal windows have been utilized to evaluate animals' thermoregulatory capacity, such as the orbital region, the auricle or ear pavilion region, the tail, and the interscapular zone where brown adipose tissue (BAT) is stored. However, the sensitivity and specificity of these windows are still subject to controversy because the scientific evidence that is available differs regarding the thermal information reported. Therefore, this paper aims to discuss the neurophysiological mechanisms of the vasomotor and thermogenesis responses (using BAT) in laboratory animals, the scientific usefulness of IRT, and the various thermal windows that are currently being used with laboratory animals. Evaluating laboratory animals' health and thermostability are fundamental components of all experimental designs. Alterations in either one of these parameters have been shown to trigger physiological changes that can compromise the welfare of the species and the replicability and robustness of the results obtained. Due to the nature and complexity of evaluating and managing the species involved in research protocols, non-invasive tools such as infrared thermography (IRT) have been adopted to quantify these parameters without altering them or inducing stress responses in the animals. IRT technology makes it possible to quantify changes in surface temperatures that are derived from alterations in blood flow that can result from inflammatory, stressful, or pathological processes; changes can be measured in diverse regions, called thermal windows, according to their specific characteristics. The principal body regions that were employed for this purpose in laboratory animals were the orbital zone (regio orbitalis), auricular pavilion (regio auricularis), tail (cauda), and the interscapular area (regio scapularis). However, depending on the species and certain external factors, the sensitivity and specificity of these windows are still subject to controversy due to contradictory results published in the available literature. For these reasons, the objectives of the present review are to discuss the neurophysiological mechanisms involved in vasomotor responses and thermogenesis via BAT in laboratory animals and to evaluate the scientific usefulness of IRT and the thermal windows that are currently used in research involving laboratory animals. [ABSTRACT FROM AUTHOR]

Simple Summary: In several species, facial expressions have been associated with positive and negative emotions to communicate their mental state. In dogs, the interpretation of these muscle movements is relevant because of their close bond with humans. Currently, there is a discussion about whether facial expressions in domestic dogs can communicate emotions or are simply the result of mimicry and emotional contagion. This article will discuss the available literature on dogs' facial expressions, anatomy and neurophysiology, and their association with emotions and adverse events such as pain. In this species, it is a challenge to identify and associate both factors due to domestication. This review aims to provide scientific support and understanding of facial expression in dogs as a clinical ethological tool. Animals' facial expressions are involuntary responses that serve to communicate the emotions that individuals feel. Due to their close co-existence with humans, broad attention has been given to identifying these expressions in certain species, especially dogs. This review aims to analyze and discuss the advances in identifying the facial expressions of domestic dogs and their clinical utility in recognizing pain as a method to improve daily practice and, in an accessible and effective way, assess the health outcome of dogs. This study focuses on aspects related to the anatomy and physiology of facial expressions in dogs, their emotions, and evaluations of their eyebrows, eyes, lips, and ear positions as changes that reflect pain or nociception. In this regard, research has found that dogs have anatomical configurations that allow them to generate changes in their expressions that similar canids—wolves, for example—cannot produce. Additionally, dogs can perceive emotions similar to those of their human tutors due to close human-animal interaction. This phenomenon—called "emotional contagion"—is triggered precisely by the dog's capacity to identify their owners' gestures and then react by emitting responses with either similar or opposed expressions that correspond to positive or negative stimuli, respectively. In conclusion, facial expressions are essential to maintaining social interaction between dogs and other species, as in their bond with humans. Moreover, this provides valuable information on emotions and the perception of pain, so in dogs, they can serve as valuable elements for recognizing and evaluating pain in clinical settings. [ABSTRACT FROM AUTHOR]

Simple Summary: Labour is considered a painful episode where complex physiological, hormonal, morphological, and behavioural changes are present. During animal parturition, the recognition and treatment of pain is not a regular practice, although there are several consequences derived from pain in the mother and the newborn. This review discusses current knowledge about human labour pain, the relevant rat model's contribution to human labour pain, and model parturition pain mechanisms in small and large animals. Parturition's pain represents a potential welfare concern; therefore, pain indicators and appropriate analgesic therapy are also analyzed in this work including the relevance of analgesics and the welfare implications of pain during this physiological stage. Parturition is a complex physiological process and involves many hormonal, morphological, physiological, and behavioural changes. Labour is a crucial moment for numerous species and is usually the most painful experience in females. Contrary to the extensive research in humans, there are limited pain studies associated with the birth process in domestic animals. Nonetheless, awareness of parturition has increased among the public, owners, and the scientific community during recent years. Dystocia is a significant factor that increases the level of parturition pain. It is considered less common in polytocous species because newborns' number and small size might lead to the belief that the parturition process is less painful than in monotocous animal species and humans. This review aims to provide elements of the current knowledge about human labour pain (monotocous species), the relevant contribution of the rat model to human labour pain, and the current clinical and experimental knowledge of parturition pain mechanisms in domestic animals that support the fact that domestic polytocous species also experience pain. Moreover, both for women and domestic animal species, parturition's pain represents a potential welfare concern, and information on pain indicators and the appropriate analgesic therapy are discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: Fighting bulls that participate in bullfighting face energy and metabolic demands due to the high intensity and duration of the exercise performed. Under these conditions, specific corporal mechanisms, such as the acid–base balance, are affected, causing metabolic acidosis. However, fighting bulls also undergo muscular injuries, physiological changes, and high enzyme concentrations that reflect the stress to which they are subjected, and in some bulls, bullfights can trigger electrolytic imbalances that include hypercalcaemia, hypermagnesaemia, and hyperphosphataemia, exacerbated by muscular necrosis and myoglobinuria. During bullfights, bulls undergo physiometabolic responses such as glycolysis, anaerobic reactions, cellular oedema, splenic contraction, and hypovolemic shock. The objective of this review article is to present the current knowledge on the factors that cause stress in fighting bulls during bullfights, including their dying process, by discussing the neurobiology and their physiological responses. The literature shows that biochemical imbalances occur during bullfights, including hypercalcaemia, hypermagnesaemia, hyperphosphataemia, hyperlactataemia, and hyperglycaemia, associated with increased endogenous cortisol and catecholamine levels. Creatine kinase, citrate synthase, and lactate dehydrogenase levels also increase, coupled with decreases in pH, blood bicarbonate levels, excess base, partial oxygen pressure, and oxygen saturation. The intense exercise also causes a marked decrease of glycogen in type I and II muscle fibres that can produce myoglobinuria and muscular necrosis. Other observations suggest the presence of osteochondrosis. The existing information allows us to conclude that during bullfights, bulls face energy and metabolic demands due to the high intensity and duration of the exercise performed, together with muscular injuries, physiological changes, and high enzyme concentrations. In addition, the final stage of the bullfight causes a slow dying process for an animal that is sentient and conscious of its surroundings. [ABSTRACT FROM AUTHOR]

Simple Summary: Morphological variability in canines is associated with the mother's size and weight, which likely affects the birth weight of the puppies and their metabolic status. Identifying physio-metabolic alterations in the blood from the umbilical vein to evaluate the concentration of gases, glucose, lactate, calcium, hematocrit levels, and blood pH of newborn puppies will make it possible to determine the risk of complications due to intrauterine asphyxia. The objective of this study is to evaluate the effect of the mother's weight on the weight of liveborn and stillborn puppies during spontaneous births and the neonates' blood physiological alterations during the first minute of life. The above allowed us to identify the physio-metabolic maladjustments that newborn puppies suffer from and to determine the risk of asphyxia according to the weight category of the mothers. Results suggest that if the weight of the bitch is >16.1 kg in eutocic births, there is a higher risk of intrapartum physiological alterations and death. The results of this study allowed us to identify that the weight of dams before birth determines the weight of the puppies at birth, though there is a wide range in birth weights due to the ample morphological variability characteristics of this species. This study aims to determine the effect of the weight of bitches on liveborn and stillbirth puppies from eutocic births, and physiological blood alterations during the first minute postpartum. A total of 52 female dogs were evaluated and distributed in four categories: C1 (4.0–8.0 kg, n = 19), C2 (8.1–16.0 kg, n = 16), C3 (16.1–32.0 kg, n = 11), and C4 (32.1–35.8 kg, n = 6). The dams produced 225 liveborn puppies and 47 were classified as stillbirth type II. Blood samples were taken from the umbilical vein to evaluate the concentration of gases, glucose, lactate, calcium, hematocrit levels, and blood pH. The liveborn puppies in C2, C3, and C4 had more evident physiological alterations (hypercapnia, acidosis) than those in C1 (p < 0.05). These signs indicate a process of transitory asphyxiation. The stillborn pups in all four categories had higher weights than their liveborn littermates. C3 and C4 had the highest mean weights (419.86 and 433.79 g, respectively) and mortality rates (C3 = 20.58%, C4 = 24.58%). Results suggest that if the weight of the bitch is >16.1 kg in eutocic births, there is a higher risk of intrapartum physiological alterations and death. The results of this study allowed us to identify that the weight of dams before birth determines the weight of the puppies at birth. [ABSTRACT FROM AUTHOR]

Simple Summary: The current immune, metabolic, and neural pathways and the structures involved in developing the febrile response and, in return, to thermal homeostasis are known. There is still much information to be revealed about the underlying mechanisms that participate in the febrile process and the control of energy balance. This review analyzes the recent advances in pathophysiological mechanisms of the febrile process, the heat loss in an animal with fever, thermoregulation, the adverse effects of fever, and recent scientific findings related to different pathologies in farm animals through the use of infrared thermography, a fast, reliable, and non-invasive tool that is useful in the early detection of pathologies of clinical importance. Body-temperature elevations are multifactorial in origin and classified as hyperthermia as a rise in temperature due to alterations in the thermoregulation mechanism; the body loses the ability to control or regulate body temperature. In contrast, fever is a controlled state, since the body adjusts its stable temperature range to increase body temperature without losing the thermoregulation capacity. Fever refers to an acute phase response that confers a survival benefit on the body, raising core body temperature during infection or systemic inflammation processes to reduce the survival and proliferation of infectious pathogens by altering temperature, restriction of essential nutrients, and the activation of an immune reaction. However, once the infection resolves, the febrile response must be tightly regulated to avoid excessive tissue damage. During fever, neurological, endocrine, immunological, and metabolic changes occur that cause an increase in the stable temperature range, which allows the core body temperature to be considerably increased to stop the invasion of the offending agent and restrict the damage to the organism. There are different metabolic mechanisms of thermoregulation in the febrile response at the central and peripheral levels and cellular events. In response to cold or heat, the brain triggers thermoregulatory responses to coping with changes in body temperature, including autonomic effectors, such as thermogenesis, vasodilation, sweating, and behavioral mechanisms, that trigger flexible, goal-oriented actions, such as seeking heat or cold, nest building, and postural extension. Infrared thermography (IRT) has proven to be a reliable method for the early detection of pathologies affecting animal health and welfare that represent economic losses for farmers. However, the standardization of protocols for IRT use is still needed. Together with the complete understanding of the physiological and behavioral responses involved in the febrile process, it is possible to have timely solutions to serious problem situations. For this reason, the present review aims to analyze the new findings in pathophysiological mechanisms of the febrile process, the heat-loss mechanisms in an animal with fever, thermoregulation, the adverse effects of fever, and recent scientific findings related to different pathologies in farm animals through the use of IRT. [ABSTRACT FROM AUTHOR]

Simple Summary: Infrared thermography is a clinically useful method for detecting physiopathological alterations in animals through microvascular changes. It has been adapted for applications with large species, as a support tool in evaluating animal welfare, and can also contribute to productive and reproductive evaluations. This review discusses the thermal windows currently in use and characterizes their differences and limitations as resources for early detection and diagnosis in cattle and river buffaloes. Infrared thermography (IRT) is a non-ionizing, non-invasive technique that permits evaluating the comfort levels of animals, a topic of concern due to the growing interest in determining the state of health and welfare of production animals. The operating principle of IRT is detecting the heat irradiated in anatomical regions characterized by a high density of near-surface blood vessels that can regulate temperature gain or loss from/to the environment by modifying blood flow. This is essential for understanding the various vascular thermoregulation mechanisms of different species, such as rodents and ruminants' tails. The usefulness of ocular, nasal, and vulvar thermal windows in the orbital (regio orbitalis), nasal (regio nasalis), and urogenital (regio urogenitalis) regions, respectively, has been demonstrated in cattle. However, recent evidence for the river buffalo has detected discrepancies in the data gathered from distinct thermal regions in these large ruminants, suggesting a limited sensitivity and specificity when used with this species due to various factors: the presence of hair, ambient temperature, and anatomical features, such as skin thickness and variations in blood supplies to different regions. In this review, a literature search was conducted in Scopus, Web of Science, ScienceDirect, and PubMed, using keyword combinations that included "infrared thermography", "water buffalo", "river buffalo" "thermoregulation", "microvascular changes", "lacrimal caruncle", "udder", "mastitis", and "nostril". We discuss recent findings on four thermal windows—the orbital and nasal regions, mammary gland in the udder region (regio uberis), and vulvar in the urogenital region (regio urogenitalis)—to elucidate the factors that modulate and intervene in validating thermal windows and interpreting the information they provide, as it relates to the clinical usefulness of IRT for cattle (Bos) and the river buffalo (Bubalus bubalis). [ABSTRACT FROM AUTHOR]

Simple Summary: The study of the hypothalamic neuromodulation of thermoregulation offers broad areas of opportunity with practical applications that are currently being strengthened by the availability of efficacious tools like infrared thermography (IRT). This review analyzes the effect of climate change on behavior and productivity; and the effects of exercise on animals involved in sporting activities; identifies the microvascular changes that occur in response to fear, pleasure, pain, and other situations that induce stress in animals; and examines thermoregulating behaviors. This review analyzes the main anatomical structures and neural pathways that allow the generation of autonomous and behavioral mechanisms that regulate body heat in mammals. The study of the hypothalamic neuromodulation of thermoregulation offers broad areas of opportunity with practical applications that are currently being strengthened by the availability of efficacious tools like infrared thermography (IRT). These areas could include the following: understanding the effect of climate change on behavior and productivity; analyzing the effects of exercise on animals involved in sporting activities; identifying the microvascular changes that occur in response to fear, pleasure, pain, and other situations that induce stress in animals; and examining thermoregulating behaviors. This research could contribute substantially to understanding the drastic modification of environments that have severe consequences for animals, such as loss of appetite, low productivity, neonatal hypothermia, and thermal shock, among others. Current knowledge of these physiological processes and complex anatomical structures, like the nervous systems and their close relation to mechanisms of thermoregulation, is still limited. The results of studies in fields like evolutionary neuroscience of thermoregulation show that we cannot yet objectively explain even processes that on the surface seem simple, including behavioral changes and the pathways and connections that trigger mechanisms like vasodilatation and panting. In addition, there is a need to clarify the connection between emotions and thermoregulation that increases the chances of survival of some organisms. An increasingly precise understanding of thermoregulation will allow us to design and apply practical methods in fields like animal science and clinical medicine without compromising levels of animal welfare. The results obtained should not only increase the chances of survival but also improve quality of life and animal production. [ABSTRACT FROM AUTHOR]

Simple Summary: Placentophagia is the ingestion of the placenta and afterbirth components released during and after parturition. The maternal behavior is widespread in mammalians and takes place in nonhuman primates too. It can occur between related and unrelated female primates and female and male weanling siblings in rats and hamsters. There are reports of human placentophagia in North America where women consume their placenta, whether raw, cooked, dehydrated, processed, or encapsulated, assuming potential health benefits for mothers and their offspring. However, there are also possible detrimental health risks associated with placental consumption in women. There is no scientific research regarding the beneficial effects of human placentophagia, and available information is mostly hearsay. We discuss the cause-effect of placentophagy and the endocrine, nutritional, and analgesic proposed benefits and adverse effects of this practice that have been published in humans and nonhuman mammals. Placentophagia is a common mammalian behavior, and the first scientific study of the potential effects of human maternal placentophagia on lactation was in 1917. More recently, in the 1970s, human placentophagia was reported in North America with a trend toward increased consumption. There are different hypotheses about the women and nonhuman mammals' motivation towards placentophagia, but few have been subject to hypotheses testing. In women, the controversy continues; on the one hand, researchers attribute benefits like increased breast milk, weight gain in newborns, decreased postpartum depression and fatigue, and improved mothers' mood. In contrast, bacterial or viral infections, hormonal, or trace elements that could become toxic for both the mother and baby are reported as possible health risks. Other reports argue a lack of scientific rigor to support the self-reported benefits of placentophagia. Also, the way the placenta is prepared (raw, cooked, dehydrated, processed, or encapsulated) alters its components, and thus the desired effects. This review provides relevant information and the different hypotheses and points of view around placentophagia. However, there are still questions to be resolved, and more studies are needed to confirm or reject the data generated so far about placentophagia in humans and nonhuman mammals. [ABSTRACT FROM AUTHOR]

Simple Summary: Grimace scales for laboratory animals were first reported ten years ago. Yet, despite their promise as pain assessment tools it appears that they have not been implemented widely in animal research establishments for clinical pain assessment. We discuss potential reasons for this based on the knowledge gained to date on their use and suggest avenues for further research, which might improve uptake of their use in laboratory animal medicine. Animals' facial expressions are widely used as a readout for emotion. Scientific interest in the facial expressions of laboratory animals has centered primarily on negative experiences, such as pain, experienced as a result of scientific research procedures. Recent attempts to standardize evaluation of facial expressions associated with pain in laboratory animals has culminated in the development of "grimace scales". The prevention or relief of pain in laboratory animals is a fundamental requirement for in vivo research to satisfy community expectations. However, to date it appears that the grimace scales have not seen widespread implementation as clinical pain assessment techniques in biomedical research. In this review, we discuss some of the barriers to implementation of the scales in clinical laboratory animal medicine, progress made in automation of collection, and suggest avenues for future research. [ABSTRACT FROM AUTHOR]