As pork consumption increases, consumer demand for high-quality meat has also increased. To improve pork quality, minimizing stress throughout the slaughter process is essential. Implementation of animal welfare measures can reduce stress, and the stunning stage, which renders animals unconscious, is crucial for ensuring animal welfare, slaughter efficiency, and final meat quality. Previous studies focused on the changes that occur in physiological and physicochemical characteristics following electrical and gas stunning. Using transcriptome analysis, this study aimed to elucidate the changes in gene expression and molecular-level biological responses to electrical and CO2 gas stunning methods. The two stunning methods (electrical stunning, 10 pigs; CO2-controlled atmosphere stunning, 10 pigs) were compared based on transcriptomic changes determined by whole-blood RNA-Seq. Differentially expressed genes were identified for each group (electrical stunning: 67 upregulated and 37 downregulated genes; CO2-controlled atmosphere stunning: 39 upregulated and 17 downregulated genes). Biological mechanisms associated with pig responses to stunning methods were identified through functional annotation. Under electrical stunning conditions, tissue damage responses such as extracellular matrix stability degradation and potential inflammatory reactions were observed. By contrast, under CO2-gas stunning conditions, defense and physiological regulatory mechanisms to buffer oxidative stress were induced, accompanied by immune balance and tissue protection mechanisms. Our study revealed distinct biological mechanisms underlying pig responses to different stunning methods, suggesting that these mechanisms could serve as a cornerstone for assessing slaughter stress, enhancing meat quality, and improving animal welfare.
Slaughterhouses for all animals, including reindeer, must achieve the goal of high animal welfare. They must carry out regular checks on stunning effectiveness and key parameters to ensure that animals do not display any signs of consciousness, and display the expected signs of unconsciousness, in the period between stunning and death. The official control verifying this performance must be based on scientific evidence. Experience gained and scientific development are to be considered when control and regulations are developed. The purpose of this study was to evaluate penetrative captive bolt-stunning quality in stunning of reindeer (Rangifer tarandus tarandus L.). We investigated stun-to stick interval in relation to indicators of consciousness and unconsciousness as well as factors affecting the time between stunning and sticking to generate evidence-based knowledge for optimising animal welfare by best practise at stunning. Stun-to-stick interval was measured for 1,590 reindeer during eight slaughter days at two abattoirs during slaughter season 2015-2016. The variables recorded were abattoir (AA, AB), season, type of stunning (cartridge-powered/ pneumatic captive bolt gun), level of experience of the stunning operator (one/three/five years), animal category (calf/male/female), and origin of the reindeer (mountain/forest), number of stunning attempts per reindeer, indicators of possible remaining or regaining of consciousness and indicators of unconsciousness until the end of bleeding. Mean stun-to-stick interval for effective stuns was 44.1 s (95% confidence interval (CI 95%) = 43.6-44.6). Longer stunning experience was associated with shorter mean stun-to-stick interval (P < 0.001) as well as a quicker slaughter hoisting process in one of the two abattoirs (P = 0.016). In 5.3% (83/1,569) of one-shot stuns, stun-to-stick interval exceeded 60 s, where stunning operators with short experience had significantly more cases than more experienced operators (P < 0.001). Ineffective stuns (> one shot/reindeer), with continued standing posture of a reindeer post-shot, comprised 1.3% (21/1590) of all stuns with significant relationship to adult male reindeer and none to stunning operator experience. Proper standard operating procedures including maintain of equipment as well as a supervised training period for operators as suitable risk management activities are recommended. Official controls could be most effective by focusing on these factors.
Pre-slaughter handling and slaughter practices are crucial in determining broiler chicken meat's quality and market value. Despite the widespread adoption of stunning in commercial poultry production, its influence on meat quality remains contentious, particularly from the perspective of consumer preference and halal compliance. This meta-analysis quantitatively evaluated the effects of electrical stunning and halal slaughter on the meat quality of broiler chickens. Studies published between 2010 and 2024 were systematically searched across five databases. Eight of the 1,018 identified studies met the inclusion criteria and were subjected to meta-analysis. Standardized mean difference (SMD) and corresponding 95% CI were calculated using a random effects model. Detected heterogeneity was assessed by subgroup and meta-regression analyses. The meta-analysis revealed that electrical stunning significantly improved early pH (≤4 h), ultimate pH (24 h), water holding capacity (WHC), yellowness, and fat content, while halal slaughter resulted in higher redness. Among strains, Cobb 500 showed greater responsiveness in early pH, WHC, and yellowness, suggesting genetic influence on stunning tolerance. Water bath electrical stunning (WBES) significantly increased early pH, indicating more stable postmortem metabolism. Lower electrical current intensity significantly increased early pH, ultimate pH, and yellowness of broiler breast muscle. Furthermore, longer stunning durations were positively correlated with higher early pH (Estimate = 1.5959; R2 = 82.65), and fat content (Estimate = 0.6284; R2 = 91.73), but decreased redness (Estimate = -0.2871; R2 = 30.74). Slaughter age explained all between-study variation observed in yellowness (Estimate = 0.1581; R² = 100%), with older birds producing more yellowish meat due to increased fat deposition. In summary, electrical stunning effectively enhanced key meat quality traits in broiler breast muscle; however, its impact is moderated by strain, stunning method, electrical current intensity, slaughter age, and stunning duration. This provides useful guidance on the application of electrical stunning on commercial broiler chickens for improved meat quality and increased consumer acceptability.
Electrical water-bath stunning remains the predominant method used in commercial poultry slaughter worldwide yet its effectiveness and welfare implications may vary among breeds. Taiwanese red-feathered chickens differ from commercial broilers in growth rate and body composition, which may influence their response to electrical stunning. This study investigated the relationships between electrical stunning conditions, electroencephalographic (EEG) indicators of unconsciousness, behavioural reflexes, and carcass quality in Taiwanese red-feathered chickens. A total of 200 female chickens were subjected to direct-current water-bath stunning at 80, 100, 120, 140, or 160 V for 7 s. EEG activity and physical indicators of consciousness were assessed during the first 40 s after stunning, and carcass defects were evaluated post-mortem. Of the 200 birds initially evaluated, EEG data from 153 birds met predefined signal quality criteria and were included in the final analysis. EEG-defined unconsciousness was more frequent and lasted longer at higher voltages (140-160 V), although intermediate voltage levels (e.g., 120 V) did not follow a strictly linear trend. Corneal reflex and spontaneous eye blinking were strongly associated with EEG-based unconsciousness, supporting their use as practical on-site welfare indicators. At the lowest voltage (80 V), birds with higher abdominal fat percentages were more likely to be effectively stunned. In contrast, no statistically significant associations between abdominal fat percentage and stunning effectiveness were observed at 100-160 V. However, higher voltages were also associated with an increased prevalence and severity of carcass defects. These findings suggest that stunning conditions or commercial broilers may not ensure effective unconsciousness in Taiwanese red-feathered chickens. Corneal reflex and spontaneous eye blinking provide reliable, welfare-relevant indicators of unconsciousness under field conditions. Electrical settings must be carefully balanced to achieve effective stunning while minimising adverse welfare outcomes associated with excessive neuro-muscular responses.
Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) may cause stress-induced transient acute cardiac dysfunction through myocardial stunning, in the form of exacerbation-triggered Takotsubo syndrome (referred to as Takotsubo stunning). Although prior studies suggest an association between AECOPD and transient cardiac dysfunction, existing evidence is limited to retrospective cohorts, case reports and expert consensus. Therefore, the incidence and clinical impact of Takotsubo stunning with acute heart failure (AHF) during AECOPD remain unknown and may be overlooked due to overlapping clinical symptoms. Cardiac Assessment and Takotsubo-stunning among COPD-exacerbations in-Hospital (CATCH study) aims to determine the incidence of Takotsubo stunning during AECOPD and to evaluate its clinical implication. CATCH is a prospective observational cohort study enrolling adults (≥18 years) admitted for AECOPD at Sahlgrenska University Hospital (Gothenburg, Sweden). Participants with chronic left ventricular systolic dysfunction (left ventricular ejection fraction <50%), pre-existing chronic regional wall motion abnormalities (RWMA) or prior type 1 myocardial infarction are excluded. Following informed consent, participants undergo echocardiographic screening for RWMA and/or systolic left ventricular dysfunction. Screening-positive patients have follow-up echocardiography at 24 hours (±6) and 30 days (±48 hours). Those with reversible dysfunction constitute the CATCH case group, while screening-negative participants serve as controls. Additional assessments include ECG, chest X-ray, N-terminal pro-B-type natriuretic peptide blood analysis and COPD severity. Primary outcomes include the incidence of reversible RWMA or left ventricular dysfunction (proxy for Takotsubo stunning) and in-hospital clinical signs of AHF (Killip class >1). A sample size of 150 patients is required for detecting AHF differences (α=0.05, 80% power). The study received ethical approval from the Swedish Ethical Review Authority. All participants provided written informed consent. Results will be disseminated through peer-reviewed journals and scientific meetings. The CATCH study is registered at ClinicalTrials.gov (NCT06597331). The reference number for ethical approval is 2024-02071-01 (with addenda 2024-05448-02 and 2025-05861-02).
The EFSA Panel on Animal Health and Welfare (AHAW) was asked to deliver a scientific opinion on the use of Diathermic Syncope® (DTS) for stunning cattle. A dossier was provided by the applicant as the basis for an assessment of the extent to which the method is able to provide a level of animal welfare at least equivalent to that ensured by the currently allowed methods for stunning cattle. This scientific opinion followed the EFSA Guidance (2018) on the assessment criteria for applications for new or modified stunning methods regarding animal protection at time of killing. Under Council Regulation (EC) No 1099/2009, approval of novel stunning methods requires demonstration of (1) the absence of pain, distress or suffering until the onset of unconsciousness and (2) that the animal remains unconscious until death. An ad hoc Working Group (WG) by EFSA performed the assessment as follows: (1) check of provided data against the criteria laid down in the EFSA Guidance; (2) extensive literature search; (3) data extraction and quantitative assessment; (4) exercise based on non-formal expert elicitation and qualitative assessment. Although the data and studies provided in the dossier only partially fulfilled the necessary criteria, they were sufficient to proceed with the animal welfare risk assessment. According to the data and the use of DTS parameterised by the applicant (delivering 160-200 kJ of energy and an incident power of 16-20 kW for 10 s), DTS does not ensure a level of welfare at least equivalent to one or more of the currently allowed methods listed in Annex I of Council Regulation (EC) No 1099/2009.
People with hemodialysis-dependent kidney failure experience significantly higher cardiovascular (CV) morbidity, mortality, symptom burden, and cognitive impairment compared to the general population. Hemodialysis-induced ischemia contributes to myocardial stunning, which worsens CV outcomes. Intradialytic cycling has the potential to mitigate cardiac stunning, but its effects have not been assessed in randomized controlled trials (RCTs). This multicenter RCT evaluates the impact of 12 weeks of intradialytic cycling on hemodialysis-induced myocardial stunning. The study will recruit 160 adults (80 intervention and 80 control) receiving maintenance hemodialysis at five Canadian centers and one Australian center. Outcome assessments are conducted at baseline, 12 weeks, and 16 weeks. An intervention implementation process evaluation is part of this study. The primary outcome is change in number of regional wall motion abnormalities (RWMAs) at peak hemodialysis stress from baseline to 12 weeks. Secondary outcomes include changes in cognitive function, hemodialysis recovery time, and symptom burden. Change in number of RWMAs at peak hemodialysis stress from baseline to 12 weeks are compared between study groups using an independent 2-tailed t test and using a Poisson generalized linear mixed model with study group as a fixed effect, and time and mean ultrafiltration rate as random effects. Compared with standard care, we anticipate that intradialytic cycling will decrease myocardial stunning, resulting in improved symptom burden, and functional and cognitive status. This trial provides critical evidence regarding the benefits and feasibility of exercise during hemodialysis, potentially informing clinical practice, and guidelines for hemodialysis care.Trial registration number: NCT04877041. Les personnes atteintes d’insuffisance rénale qui dépendent de l’hémodialyse présentent une morbidité cardiovasculaire, un taux de mortalité, une déficience cognitive et un fardeau symptomatique nettement plus élevés que la population générale. L’ischémie induite par l’hémodialyse contribue à la sidération myocardique, ce qui aggrave le pronostic cardiovasculaire. Le cyclisme intradialytique a le potentiel d’atténuer la sidération cardiaque, mais ses effets n’ont pas été évalués dans des essais contrôlés randomisés (ECR). Cet ECR multicentrique évalue l’effet de 12 semaines de cyclisme intradialytique sur la sidération myocardique induite par l’hémodialyse. En tout, 160 adultes recevant une hémodialyse d’entretien (80 dans le groupe d’intervention, 80 témoins) seront recrutés au sein de cinq centres canadiens et d’un centre australien. L’évaluation des résultats sera effectuée à l’inclusion, à 12 semaines et à 16 semaines. Le processus de mise en œuvre de l’intervention fera également l’objet d’une évaluation. Le principal résultat mesuré est la variation du nombre d’anomalies régionales de la contractilité myocardique (ARCM) au pic d’effort induit par l’hémodialyse entre l’inclusion et 12 semaines. Les résultats secondaires comprennent des changements dans la fonction cognitive, le temps de récupération après l’hémodialyse et le fardeau symptomatique. La variation du nombre d’ARCM au pic d’effort induit par l’hémodialyse entre l’inclusion et 12 semaines sera comparée entre les groupes à l’aide d’un test t bilatéral indépendant. Un modèle linéaire généralisé mixte de Poisson avec effet fixe (le groupe d’intervention) et effets aléatoires (le temps et le taux moyen d’ultrafiltration) sera également utilisé. Par rapport aux soins courants, nous anticipons que le cyclisme intradialytique atténuera la sidération myocardique, ce qui se traduira par l’amélioration du fardeau symptomatique et des fonctions physiques et cognitives. Cet essai fournit des données clés sur les avantages et la faisabilité de l’exercice physique pendant l’hémodialyse, lesquelles pourraient éclairer la pratique clinique et les lignes directrices dans ce domaine.Trial registration number: NCT04877041.
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RNA metabolism in kinetoplastid protists (Kinetoplastea), including trypanosomes and Leishmania, involves unique post-transcriptional mitochondrial RNA editing that creates translatable mRNAs through uridine (U) insertions and deletions (U-indels) directed by antisense guide RNAs (gRNAs). Like other biological processes that require specific RNA targeting, this system faces several challenges beyond coordinating its many components: assembling mRNA-gRNA hybrids, recognizing hundreds of sites, and accurately distinguishing pre-edited, partially edited, and fully edited transcripts in the mitochondrial environment. In parasites such as Trypanosoma brucei, significant energetic adaptations to different host environments also involve critical editing changes during development. The editing holoenzyme includes three molecular complexes and isoforms that carry most proteins: RNA Editing Catalytic Complexes (RECCs), which catalyze U-indel cycles; RNA Editing Substrate Complexes (RESCs), which serve as scaffolds to coordinate the editing components; and the RNA Editing Helicase 2 Complex (REH2C), which contains key proteins involved in developmental editing regulation. However, more proteins and functions are being discovered. The editing system, best understood in T. brucei, shows considerable evolutionary conservation in its core machinery; however, it varies in the extent of RNA editing and the organization of mitochondrial mRNA and gRNA genes across different species. Here we explore recent progress in our understanding of RNA editing and the growing use of modern computational tools, including artificial intelligence (AI) and structural methods, to examine function, organization, developmental regulation, and evolutionary aspects of this amazing system. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Processing > RNA Editing and Modification.
Spinal fractures in pigs during electrical stunning are frequent and compromise animal welfare, meat quality, and generate economic losses. Despite the relevance of the problem, specific preventive strategies are still little explored. This research evaluated, in an unprecedented way, the effect of magnesium supplementation in drinking water during preslaughter fasting on the occurrence of these fractures. A total of 2,080 pigs were evaluated, divided into a control group (CT) with 964 animals, not supplemented and a treatment group (TG) with 1,116 animals, supplemented with magnesium in drinking water, at a concentration of 300 mg/L. The supplementation reduced the proportion of fractures from 39.4% (380/964) to 30.0% (335/1,116), with an odds ratio of 0.66, suggesting a protective effect associated with muscle relaxation. Pigs with fractures had lower water holding capacity (WHC: 0.338 vs 0.351; p = 0.0076), especially in the supplemented group (0.333 vs 0.357; p = 0.0002), confirming the relationship between skeletal injuries and meat quality. In conclusion, preslaughter supplementation with magnesium is practical and effective to reduce fractures and improve pork quality.
During commercial harvesting (shooting) of kangaroos, pouch young of shot females must be euthanased to prevent suffering. The current euthanasia method, manually applied concussive (or blunt force) trauma to the head, can be effective but is not always applied consistently and is often perceived by observers to be inhumane. The captive-bolt device (CBD), which fires a steel bolt that either penetrates or impacts the skull, could provide a more suitable alternative. We reviewed a range of potentially suitable CBDs and assessed the effectiveness of four types on live animals. Effectiveness of CBDs was determined by assessing behaviour, electroencephalogram (EEG) and evaluating brain and skull trauma post mortem. Pouch young were also euthanased using manual blunt force trauma for comparison. Shooting with a penetrating CBD produced brain activity that was inconsistent with consciousness in 100% (n = 20) of animals. Behavioural indicators of consciousness and normal-like EEG were not detected after shooting with the CBD and damage to the brain was extensive. Seven out of 29 (24%) joeys shot with a non-penetrating CBD were either still breathing (n = 1) or recovered breathing (n = 6) after shooting. All seven animals had no or only mild damage to the medulla. We conclude that a cartridge-powered, penetrating CBD and manual blunt force trauma can both achieve immediate unconsciousness in pouch young, but a second step to exsanguinate the animal must still be performed. Penetrating CBDs are preferred to manual blunt force trauma since they are more repeatable, less reliant upon operator skill and confidence and more likely to reduce animal (and observer) distress.
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Intercoronary communication (ICC) is an extremely rare congenital coronary anomaly that is generally considered benign. We herein report a novel case in which an ICC itself caused coronary vasospasm, leading to myocardial ischemia. A 79-year-old woman presented with rest angina. Transthoracic echocardiography revealed hypokinesia of the posterolateral left ventricular wall. Coronary angiography demonstrated an ICC between the left circumflex artery and right coronary artery, and acetylcholine-induced focal coronary vasospasm was provoked exclusively in the ICC and was relieved with intracoronary isosorbide dinitrate. The patient was treated with oral vasodilators, after which she remained symptom-free. Follow-up echocardiography showed complete recovery of wall motion. This case illustrates a paradoxical scenario in which an ICC, typically considered as a "safety valve," instead caused localized vasospastic myocardial ischemia. ICC itself may cause coronary vasospasm, resulting in myocardial ischemia.
Pharmacological and electrical cardioversion of atrial fibrillation (AF) is associated with markedly increased (>10-fold) risk of thromboembolic events clustering within 7 days following sinus rhythm restoration. Current evidence indicates that post-cardioversion thrombus formation from atrial stunning, rather than preexisting thrombus, causes most thromboembolic complications. Risk factors include traditional CHA2DS2-VASc components (particularly heart failure), AF duration ≥12 h, mitral valve stenosis, cardiac amyloidosis and hypertrophic cardiomyopathy. While placebo-controlled randomized trials are lacking, there is overwhelming observational evidence that oral anticoagulation (OAC) reduces post-cardioversion thromboembolism by 60-80 % to a residual risk of approximately 0.5 %. This benefit seems independent of CHA2DS2-VASc and AF duration (including <48 h). Current guidelines recommend OAC for ≥3 weeks before and ≥4 weeks after cardioversion, or to rule out intracardiac thrombus by imaging, with OAC immediately before cardioversion and for ≥4 weeks. The safety of this strategy was validated in large prospective trials. However, alternative durations of pre-/post-cardioversion OAC have never been tested in randomized trials. The optimal duration of pre-cardioversion OAC remains unclear. Shorter pre-cardioversion delay is associated with increased success of cardioversion, reduced AF recurrence, reduced severity and duration of atrial stunning, and possibly reduced thromboembolic complications. Likewise, antiarrhythmic drug (AAD) pre-treatment improves cardioversion outcomes but is sometimes withheld by fear of early sinus rhythm restoration and associated thromboembolic risk. Randomized data from the ACUTE trial have shown that early AAD introduction was safe. Given the short-lived but dramatic increase in thromboembolic risk post-cardioversion, intensifying OAC immediately before cardioversion might further reduce risk, as suggested by observational studies.
Takotsubo cardiomyopathy (TTC) complicated by sinus arrest and third-degree atrioventricular block (AVB) is extremely rare. This case illustrates the utility of 18F-FDG PET/CT (fluorodeoxyglucose positron emission tomography/computed tomography) in characterizing myocardial stunning of TTC with dual nodal dysfunction and provides insights into long-term conduction outcomes. A 77-year-old female presented with acute chest pain and palpitations due to emotional stress. Echocardiography showed left ventricular (LV) apical hypokinesis [global longitudinal strain (GLS) -14.8%], coronary computed tomography angiography revealed mild mid-left anterior descending artery stenosis, and cardiac biomarkers were elevated (troponin-T: 0.0803 ng/mL; N-terminal pro-B-type natriuretic peptide: 696.92 ng/L). Holter monitoring documented sinus arrest, third-degree AVB, and a minimum heart rate of 31 b.p.m. Fluorodeoxyglucose positron emission tomography/computed tomography showed increased glucose uptake in the LV apex (consistent with myocardial stunning/inflammation), while technetium-99m methoxyisobutylisonitrile SPECT/CT detected mild apical hypoperfusion. A dual-chamber pacemaker was implanted for refractory bradycardia. At 1-month follow-up, LV apical hypokinesis resolved (GLS -19.0%), with recovered AV nodal but persistent sinoatrial nodal dysfunction. Fluorodeoxyglucose positron emission tomography/computed tomography is valuable for clarifying the metabolic basis of TTC-related myocardial dysfunction, complementing perfusion imaging. Early pacing evaluation is critical for TTC patients with sinoatrial nodal impairment-even with AV nodal recovery, persistent sinoatrial dysfunction may require long-term pacing support to prevent bradycardia-related adverse events.
Isolated right ventricular (RV) Takotsubo cardiomyopathy is a rare stress-induced variant characterized by acute RV failure with preserved left ventricular function. A 43-year-old woman with prior gastric bypass surgery presented with abdominal pain, hypotension, chest tightness, and dyspnea. Echocardiography demonstrated severe RV free wall hypokinesis with preserved apical contraction, moderate RV enlargement, and normal left ventricular function. Pulmonary embolism, obstructive coronary disease, and secondary causes of RV failure were excluded by computed tomography, coronary angiography, and right heart catheterization. Supportive management resulted in complete recovery of RV function. This case illustrates the challenge of evaluating isolated acute RV failure. Multimodal imaging was essential to distinguish primary RV myocardial stunning from other etiologies of RV dysfunction. RV Takotsubo cardiomyopathy should be considered when assessing a patient with isolated acute RV failure and is a diagnosis of exclusion.
Still's disease can precipitate macrophage activation syndrome (MAS) and, rarely, acute cardiac dysfunction. We describe MAS-associated cardiogenic shock in which myocardial stunning appeared more likely than overt myocarditis. A 20-year-old woman with Still's disease on anakinra and corticosteroids presented with status epilepticus after missing medications. She developed acute biventricular failure and cardiogenic shock. Infectious evaluation was negative. Troponin elevation was modest, while N-terminal pro-B-type natriuretic peptide was markedly increased (8,000 ng/L). High-dose intravenous methylprednisolone (500 mg/d for 3 days) and reinitiation of anakinra produced rapid hemodynamic stabilization and ventricular recovery. The clinical course suggests cytokine-mediated myocardial dysfunction, although myocarditis could not be fully excluded. Prompt recognition of MAS and early initiation of corticosteroids and IL-1 blockade are essential for reversibility of cardiac impairment. MAS can cause reversible cardiogenic shock in Still's disease. HLA-DRB1∗15 may signal susceptibility to more severe inflammatory phenotypes.
Jewish shechita and Islamic halal are distinct yet similar forms of slaughter by exsanguination via ventral neck incision (SEVNI); neither permits preslaughter stunning. SEVNI has been criticized on the grounds that the vertebral arteries in cattle, which remain intact after SEVNI, may continue to supply blood to the brain, potentially delaying loss of consciousness (LOC) and causing unnecessary pain and distress to the animal. In this context, LOC is the loss of cortical awareness, which by definition abolishes sensibility and pain perception. The objective of this review is to evaluate the literature that specifically addresses the role of the vertebral artery in brain perfusion following SEVNI. This study was not funded. A non-registered systematic search of PubMed, Google Scholar, the Cochrane Library, Medline, and Web of Science (last searched 02/10/2026) identified experimental, observational and physiological studies that assessed vertebral artery hemodynamics and/or evaluated the functional significance of the vertebral artery in cattle. Non-cattle studies, studies lacking relevant measures, reviews, commentaries, and abstracts without full text were excluded. Quantitative pooling (meta-analysis) was not performed due to methodological and outcome variability therefore results were synthesized narratively. Thirteen studies were included, with all articles independently reviewed by co-authors to minimize risk of bias. Using the ROBINS-I framework, the overall risk of bias across included studies was assessed as moderate. Across the reviewed studies, evidence consistently demonstrated that immediately following SEVNI, vertebral blood flow and pressure decrease to negligible levels, with most residual flow diverted away from the cerebral cortex. Study limitations include heterogeneous study designs, variable outcomes and methods. The available evidence indicates that vertebral artery flow following SEVNI is unlikely to be sufficient to sustain cortical perfusion, support integrated cortical function or delay LOC.