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Bini de Lima AC, Sebastião da Fé VC, Palermo Hernandes MS, Oliveira dos Santos VM. Olfactory Stimulation as Environmental Enrichment for Domestic Horses-A Review. Animals (Basel) 2023; 13:3180. [PMID: 37893904 PMCID: PMC10603683 DOI: 10.3390/ani13203180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/18/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
Horses constantly face several challenges inherent to the domestic environment, and it is common for the expression of their natural behavior to be drastically limited. Environmental enrichment has been suggested as an alternative to improve the captive situation of domestic horses. Among the recently proposed enrichment strategies, olfactory stimulation has emerged as a method for improving several aspects related to animal behavior. Olfaction is a sensory modality that plays a significant role in the expression of equine behavior, and in recent years, studies have shown that olfactory stimulation can influence the physiological and behavioral parameters of horses. This review provides current information on the anatomical particularities of the equine olfactory system, presents the physiological mechanisms involved in the odor detection process, and demonstrates how stress can interfere with this process. Finally, the use of olfactory stimulation as an environmental enrichment for domestic horses (Equus ferus caballus) is explored. The need for new studies that answer pertinent questions related to this topic is discussed throughout the manuscript.
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Affiliation(s)
- Ana Caroline Bini de Lima
- Nucleus of Studies in Ambience, Bioclimatology, Welfare and Ethology, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Brazil; (V.C.S.d.F.); (M.S.P.H.); (V.M.O.d.S.)
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Tilley P, Simões J, Sales Luis JP. Effects of a 15° Variation in Poll Flexion during Riding on the Respiratory Systems and Behaviour of High-Level Dressage and Show-Jumping Horses. Animals (Basel) 2023; 13:ani13101714. [PMID: 37238147 DOI: 10.3390/ani13101714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 04/29/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
From previous studies, the International Society for Equitation Science has advised that further research be conducted on the physiological/psychological effects of less-exacerbated poll flexion angles. We aimed to evaluate the effects of two riding poll flexion positions with a difference of only 15° on the respiratory systems and behaviour of horses through an evaluation of dynamic airway collapse via over-ground endoscopy, the pharyngeal diameter, pleural pressure, arterial oxygenation and lactate, HR/RR, and the occurrence of conflict behaviours. Twenty high-level dressage and twenty show-jumping horses underwent a 40 min ridden test at a ground angle of 85°; 3 weeks later, they underwent a ridden test at a 100° ground angle (the angle between the ground and the line from the forehead to the muzzle) and in a cross-over design. Using a mixed model for repeated measures, Wilcoxon/Friedman tests were carried out according to the experimental design and/or error normality. For both groups, at 100°, conflict behaviours and upper airway tract abnormalities were significantly more frequent, and the pleural pressure was higher, and the pharyngeal diameter was lower. At 85°, relaxation behaviours were significantly more frequent. Lactate was significantly higher at 100° only in the dressage horses. Compared to the first test at 85°, the HR/RR were significantly lower at the beginning of the second test (at 100°) but higher at the end. The significant differences identified in these dressage and show-jumping horses support the idea that an increase of just 15° in riding poll flexion can have negative effects on the respiratory system and behaviour of a horse and therefore on its welfare.
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Affiliation(s)
- Paula Tilley
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Av. Universidade Técnica, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 5000-801 Lisbon, Portugal
| | - Joana Simões
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Av. Universidade Técnica, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 5000-801 Lisbon, Portugal
- Equine Clinical Academic Department, Faculty of Veterinary Medicine, Lusófona University, 1749-024 Lisbon, Portugal
| | - José Paulo Sales Luis
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Av. Universidade Técnica, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 5000-801 Lisbon, Portugal
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Harvey AM, Beausoleil NJ, Ramp D, Mellor DJ. Mental Experiences in Wild Animals: Scientifically Validating Measurable Welfare Indicators in Free-Roaming Horses. Animals (Basel) 2023; 13:ani13091507. [PMID: 37174544 PMCID: PMC10177449 DOI: 10.3390/ani13091507] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
The mental experiences of animals are what characterises their welfare status. The Five Domains Model for assessing welfare aligns with the understanding that physical and mental states are linked. Following measurement of indicators within each of the four physical/functional Domains (1. Nutrition; 2. Physical environment; 3. Health; and 4. Behavioural interactions), the anticipated negative or positive affective consequences (mental experiences) are cautiously inferred and assigned to Domain 5. Those inferences derive credibility from validated knowledge of the underlying systems of physiology, neurophysiology, neuroethology and affective neuroscience. Any indicators used for assessing welfare need to be scientifically validated. This requires, firstly, evidence of the links between a measurable/observable indicator and the physical/functional impact (in Domains 1 to 4), and secondly, a demonstrable relationship between the physical/functional impact and the mental experience it is inferred the indicators reflect (in Domain five). This review refers to indicators of physical/functional states in Domains 1 to 4, which have been shown to be measurable in free-roaming wild horses, and then evaluates the scientific evidence linking them to inferred mental experiences in Domain 5. This is the first time that the scientific evidence validating a comprehensive range of welfare indicators has been synthesised in this way. Inserting these indicators into the Five Domains Model enables transparently justifiable assessment and grading of welfare status in free-roaming horses.
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Affiliation(s)
- Andrea M Harvey
- Centre for Compassionate Conservation, TD School, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Ngaio J Beausoleil
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, Palmerston North 4442, New Zealand
| | - Daniel Ramp
- Centre for Compassionate Conservation, TD School, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - David J Mellor
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, Palmerston North 4442, New Zealand
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Fitzharris LE, Hezzell MJ, McConnell AK, Allen KJ. Training the equine respiratory muscles: Inspiratory muscle strength. Equine Vet J 2023; 55:306-314. [PMID: 35711132 PMCID: PMC10084158 DOI: 10.1111/evj.13606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 05/27/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Little is known about the response of the equine respiratory muscles to training. OBJECTIVES To measure an index of inspiratory muscle strength (IMSi) before and after a period of conventional exercise training (phase 1) and inspiratory muscle training (IMT), comparing high-load (treatment) and low-load (control) groups (phase 2). STUDY DESIGN Prospective randomised controlled trial. METHODS Phase 1: Twenty National Hunt Thoroughbred racehorses performed an inspiratory muscle strength test (IMST) twice on two occasions; when unfit at timepoint A (July), and when race fit at timepoint B (October). Phase 2: Thirty-five Thoroughbred racehorses at race fitness were randomly assigned into a high-load (treatment, n = 20) or low-load (control, n = 15) IMT group. The high-load group followed an IMT protocol that gradually increased the inspiratory pressure applied every 4 days. The low-load group underwent sham IMT with a low training load. The IMT was performed 5 days/week for 10 weeks. The IMST was performed twice on two occasions, timepoint B (October) and timepoint C (January). Conventional exercise training and racing continued during the study period. The peak IMSi values obtained from the different groups at timepoints A, B and C were compared using a Wilcoxon Signed Rank Test. RESULTS Phase 1: There was a significant increase in IMSi from timepoint A: 22.5 cmH2 O (21-25) to timepoint B: 26 cmH2 O (24-30) (p = 0.015). Phase 2: From timepoint B to C there was a significant increase in IMSi for the high-load group 34 cmH2 O (28-36) (p = 0.001) but not the low-load group 26 cmH2 O (24-30) (p = 0.929). The peak IMSi at timepoint C was significantly higher for the high-load than low-load group (p = 0.019). MAIN LIMITATIONS Single centre study with only National Hunt horses undergoing race-training included. CONCLUSIONS In horses undergoing race training there is a significant increase in IMSi in response to conventional exercise training and high-load IMT.
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Affiliation(s)
| | - Melanie J Hezzell
- Bristol Veterinary School, University of Bristol, Langford, Bristol, UK
| | | | - Kate J Allen
- Bristol Veterinary School, University of Bristol, Langford, Bristol, UK
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Luke KL, McAdie T, Warren-Smith AK, Smith BP. Bit use and its relevance for rider safety, rider satisfaction and horse welfare in equestrian sport. Appl Anim Behav Sci 2023. [DOI: 10.1016/j.applanim.2023.105855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Trialling Locally Made, Low-Cost Bits to Improve Bit-Related Welfare Problems in Cart Horses: Findings from a Study in Senegal. Animals (Basel) 2022; 13:ani13010002. [PMID: 36611612 PMCID: PMC9817802 DOI: 10.3390/ani13010002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022] Open
Abstract
Bits used for cart horses in Senegal are typically made of recovered construction iron and often have defects related to design, shape, fit and metal quality. Consequently, there is widespread presence of bit-related oral injury amongst these equids. It was hypothesised that improving bit design would ameliorate bit-related welfare issues for working cart horses. This study aimed to develop locally made alternative bit prototypes and test their efficacy as less harmful to working horses, and their acceptability to their drivers. Eight animal-based welfare indicators (four physical and four behavioural) were designed to measure positive or negative effects of the new bits. Following a testing phase to appraise and mitigate potential animal welfare risk associated with the alternative bit designs, a total of 540 driver/horse combinations were opportunistically selected across five municipalities in Senegal. Welfare indicators were observed when new bits were introduced and again after 21 weeks of daily use. The results indicated statistically significant improvements in all welfare indicators measured (i.e., lesions on lip commissures, tongue, buccal mucosa and bars; and open mouth, tongue loll, head toss/shake, and head tilt/turn behaviours). None of the drivers reported any difficulty with horse control, nor chose to revert back to their original bits. Whilst acknowledging the limitation of inability to control all potential confounding variables, these preliminary findings suggest the bit itself as an important contributor to oral injury, and the possibility to improve this through alternative bit design that is low-cost, locally produced and acceptable to drivers.
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Matsumoto T, Okumura S, Hirata S. Non-contact respiratory measurement in a horse in standing position using millimeter-wave array radar. J Vet Med Sci 2022; 84:1340-1344. [PMID: 35944981 PMCID: PMC9586033 DOI: 10.1292/jvms.22-0238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study aimed to apply radar technology to a large quadruped animal. We first
developed a non-contact respiration measurement system using millimeter-wave array radar
for a horse in standing position. Specifically, we measured the respiration of a
stationary domestic horse in stables. Simultaneously, we measured the respiration rate
using infrared thermography and developed a method for analyzing the radar information
while verifying the rate of agreement. Our results suggested that the radar technology
detected breathing and accurately measured the respiration of a horse, despite variation
in the breathing frequency. To the best of our knowledge, this is the first study to apply
a non-contact respiration measurement system using millimeter-wave array radar has been
applied to large animals in an upright position, thereby demonstrating its potential
application in animal husbandry and welfare.
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Affiliation(s)
- Takuya Matsumoto
- Faculty of Science, Shinshu University.,Research Institute for Humanity and Nature
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Holmes TQ, Brown AF. Champing at the Bit for Improvements: A Review of Equine Welfare in Equestrian Sports in the United Kingdom. Animals (Basel) 2022; 12:1186. [PMID: 35565612 PMCID: PMC9100173 DOI: 10.3390/ani12091186] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/20/2022] [Accepted: 04/30/2022] [Indexed: 01/10/2023] Open
Abstract
Equestrian sports, including racing (e.g., flat, steeple-chasing, harness or donkey derby); show-jumping; cross-country; dressage; polo; polocrosse; endurance; carriage driving; vaulting and hunting; are hugely popular in the UK, and they involve a significant number of people, both as participants and spectators, and tens of thousands of equids. In this paper, we discuss animal welfare as a complex and disputed issue, clarifying what the term means and how it can be measured. We review many aspects of welfare risk to equids used for sport, addressing issues encountered throughout their lives, including housing, feeding, veterinary intervention, shoeing, handling, training, breeding and equipment. This is followed by a unique exploration of the institutions and social processes influencing equine welfare. The institutional components comprise the rules of competition, the equids, attributes of the stakeholders and the space where participants strive to achieve a common purpose. We endeavour to untangle the most significant elements that create barriers or provide opportunities for equine welfare improvement. We expose the challenges faced by a broad range of stakeholders with differing ethics, attitudes and values. Evidently, there are many welfare risks to which equids used in sports continue to be exposed. It is also evident that significant improvements have occurred in recent times, but there remains a barrier to reducing the risks to an acceptable level. We conclude with recommendations regarding a process for change, involvement of stakeholders and management of knowledge to improve equine welfare that involves identifying and prioritising the risk factors and ultimately leading to interventions, further research and/or education.
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ASSOCIATIONS BETWEEN COMMONLY USED APPARATUS AND CONFLICT BEHAVIORS REPORTED IN THE RIDDEN HORSE IN AUSTRALIA. J Vet Behav 2021. [DOI: 10.1016/j.jveb.2021.10.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Mellor DJ, Beausoleil NJ, Littlewood KE, McLean AN, McGreevy PD, Jones B, Wilkins C. The 2020 Five Domains Model: Including Human-Animal Interactions in Assessments of Animal Welfare. Animals (Basel) 2020; 10:ani10101870. [PMID: 33066335 PMCID: PMC7602120 DOI: 10.3390/ani10101870] [Citation(s) in RCA: 222] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 10/09/2020] [Indexed: 12/21/2022] Open
Abstract
Throughout its 25-year history, the Five Domains Model for animal welfare assessment has been regularly updated to include at each stage the latest authenticated developments in animal welfare science thinking. The domains of the most up-to-date Model described here are: 1 Nutrition, 2 Physical Environment, 3 Health, 4 Behavioural Interactions and 5 Mental State. The first four domains focus attention on factors that give rise to specific negative or positive subjective experiences (affects), which contribute to the animal's mental state, as evaluated in Domain 5. More specifically, the first three domains focus mainly on factors that disturb or disrupt particular features of the body's internal stability. Each disturbed or disrupted feature generates sensory inputs which are processed by the brain to form specific negative affects, and these affects are associated with behaviours that act to restore the body's internal stability. As each such behaviour is essential for the survival of the animal, the affects associated with them are collectively referred to as "survival-critical affects". In contrast, Domain 4, now named Behavioural Interactions, focusses on evidence of animals consciously seeking specific goals when interacting behaviourally with (1) the environment, (2) other non-human animals and (3) as a new feature of the Model outlined here, humans. The associated affects, evaluated via Domain 5, are mainly generated by brain processing of sensory inputs elicited by external stimuli. The success of the animals' behavioural attempts to achieve their chosen goals is reflected in whether the associated affects are negative or positive. Collectively referred to as "situation-related affects", these outcomes are understood to contribute to animals' perceptions of their external circumstances. These observations reveal a key distinction between the way survival-critical and situation-related affects influence animals' aligned behaviours. The former mainly reflect compelling motivations to engage in genetically embedded behavioural responses, whereas the latter mainly involve conscious behavioural choices which are the hallmarks of agency. Finally, numerous examples of human-animal interactions and their attendant affects are described, and the qualitative grading of interactions that generate negative or positive affect is also illustrated.
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Affiliation(s)
- David J. Mellor
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, 4442 Palmerston North, New Zealand; (N.J.B.); (K.E.L.)
- Correspondence:
| | - Ngaio J. Beausoleil
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, 4442 Palmerston North, New Zealand; (N.J.B.); (K.E.L.)
| | - Katherine E. Littlewood
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, 4442 Palmerston North, New Zealand; (N.J.B.); (K.E.L.)
| | - Andrew N. McLean
- Equitation Science International, 3 Wonderland Ave, Tuerong, VIC 3915, Australia;
| | - Paul D. McGreevy
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia; (P.D.M.); (B.J.)
| | - Bidda Jones
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Sydney, NSW 2006, Australia; (P.D.M.); (B.J.)
- RSPCA Australia, P.O. Box 265, Deakin West, ACT 2600, Australia
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Naturalness and the Legitimacy of Thoroughbred Racing: A Photo-Elicitation Study with Industry and Animal Advocacy Informants. Animals (Basel) 2020; 10:ani10091513. [PMID: 32859112 PMCID: PMC7552286 DOI: 10.3390/ani10091513] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/19/2020] [Accepted: 08/22/2020] [Indexed: 12/26/2022] Open
Abstract
Simple Summary The international thoroughbred industry is concerned about the public’s perception of racing. Therefore, the industry’s priorities are to address the publicly most visible and known welfare violations. However, common day-to-day racing practices also impact thoroughbred welfare. In this study, key industry informants and animal advocacy informants were interviewed to find out how they view common racing practices. For the interviews, photographs of thoroughbreds on race day were used, which the informants were asked to describe. Results show industry informants often naturalise, normalise, downplay or ignore the horses’ expressions, the impact of handling on the horse and the use of equipment. The animal advocacy informants tend to describe a horse whose nature is violated. In conclusion, the industry informants show limited interest in addressing common racing practices, and this places thoroughbred welfare at risk. Both groups of informants have different ideas about what is natural and what that means for thoroughbred welfare. With society’s understanding of welfare and of racing practices growing, the racing industry may be increasingly questioned about common racing practices. This article discusses the notion of naturalness in more detail and how it can be used to advance thoroughbred protection. Abstract The idea of what is natural has particular relevance in the thoroughbred racing and breeding discourse. It guides breeding regulations; influences how the thoroughbreds’ behaviour is perceived and has implications for husbandry, handling, training and racing practices. This study investigates how key industry and animal advocacy informants based in the US, Australia and the UK conceptualise naturalness within the context of common racing practices that potentially impact the horses’ welfare. The informants were interviewed using semi-structured interviewing and photo-elicitation. Four common images of thoroughbreds on race day were presented to elicit the informants’ responses. Differences emerged between how the two groups tended to describe the images and the role naturalness played in their conceptualisations. The findings were analysed using an updated version of the Layers of Engagement with Animal Protection developed by Bergmann to situate the informants’ conceptualisations of naturalness within the wider thoroughbred protection discourse. In conclusion, the industry informants tended to defend the status quo of common racing practices. They tended to naturalise and normalise these practices and downplay their welfare impact. This poses risks for thoroughbred welfare, which are amplified by misrepresentations of what is natural. With the public’s understanding of welfare and racing practices growing, racing’s legitimacy may be further questioned. Opportunities to leverage the potential of the notion of naturalness for thoroughbred protection are discussed.
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de la Guérinière was right: Shoulder-in is beneficial for the physical and mental states of horses. J Vet Behav 2020. [DOI: 10.1016/j.jveb.2020.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Fretheim-Kelly Z, Fjordbakk CT, Fintl C, Krontveit R, Strand E. A bitless bridle does not limit or prevent dynamic laryngeal collapse. Equine Vet J 2020; 53:44-50. [PMID: 32449540 DOI: 10.1111/evj.13287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/17/2020] [Accepted: 05/09/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Bits have often been incriminated as a cause of upper respiratory tract obstruction in horses; however, no scientific studies are available to confirm or refute these allegations. Clinical signs of dynamic laryngeal collapse associated with poll flexion (DLC) are induced when susceptible horses are ridden or driven into the bit. OBJECTIVE To determine whether use of Dr Cook's™ Bitless Bridle, instead of a conventional snaffle bit bridle, would reduce the severity of DLC in affected horses measured objectively using inspiratory tracheal pressures. STUDY DESIGN Intervention study using each horse as its own control in a block randomised order. METHODS Nine Norwegian Swedish Coldblooded trotters previously diagnosed with DLC were exercised on two consecutive days using a standardised high-speed treadmill protocol with either a conventional bridle with a snaffle bit, or Dr Cook's™ Bitless Bridle. Head and neck position, rein tension, inspiratory tracheal pressure measurements, and laryngeal videoendoscopy recordings were obtained. A heart rate greater than 200 bpm, and similar degrees of poll flexion/head height, had to be achieved in both bridles for the individual horse's data to be included for comparison. RESULTS Seven horses' data met the inclusion criteria. The change in mean inspiratory tracheal pressure between free and flexion phases in the bitless bridle (-15.2 ± 12.3 cmH2 O) was significantly greater (P < .001) than in the snaffle bit bridle (-9.8 ± 7.9 cmH2 O). Mean inspiratory pressure during the free phase was significantly (P < .001) more negative with the snaffle bit bridle (-32.3 ± 6.3 cmH2 O), vs the bitless bridle (-28.5 ± 6.9 cmH2 O). Mean pressures in flexion phase, snaffle bridle (-42.1 ± 10.8 cmH2 O), vs bitless bridle (-43.7 ± 15.6 cmH2 O) where not significantly different between bridles (P = .2). MAIN LIMITATION Small sample size due to difficulty recruiting suitable clinical cases. CONCLUSIONS This study could not provide any clear evidence that the effect of a snaffle bit in a horse's mouth influences the development or severity of DLC. Instead, head and neck angles induced by rein tension seem to be the key event in provoking DLC in susceptible horses.
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Affiliation(s)
- Zoe Fretheim-Kelly
- Faculty of Veterinary Medicine, Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway.,Haukeland University Hospital, Bergen, Norway
| | - Cathrine T Fjordbakk
- Faculty of Veterinary Medicine, Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Constanze Fintl
- Faculty of Veterinary Medicine, Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | | | - Eric Strand
- Faculty of Veterinary Medicine, Companion Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
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Mellor DJ. Mouth Pain in Horses: Physiological Foundations, Behavioural Indices, Welfare Implications, and a Suggested Solution. Animals (Basel) 2020; 10:ani10040572. [PMID: 32235343 PMCID: PMC7222381 DOI: 10.3390/ani10040572] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Mouth pain in horses, specifically that caused by bits, is evaluated as a significant welfare issue. The conscious experiences of pain generated within the body generally, its roles, and its assessment using behaviour, as well as the sensory functionality of the horse’s mouth, are outlined as background to a more detailed evaluation of mouth pain. Bit-induced mouth pain elicited by compression, laceration, inflammation, impeded blood flow, and the stretching of tissues is considered. Observable signs of mouth pain are behaviours that are present in bitted horses and absent or much less prevalent when they are bit-free. It is noted that many equestrians do not recognise that these behaviours indicate mouth pain, so that the magnitude of the problem is often underestimated. The negative experiences that are most responsible for welfare compromise include the pain itself, but also, related to this pain, potentially intense breathlessness, anxiety, and fear. Finally, a series of questions is proposed to clarify issues that are relevant to increasing the adoption of bit-free bridles in order to avoid bit-induced mouth pain. Abstract A proposition addressed here is that, although bitted horses are viewed by many equestrians as being largely free of bit-related mouth pain, it seems likely that most behavioural signs of such pain are simply not recognised. Background information is provided on the following: the major features of pain generation and experience; cerebrocortical involvement in the conscious experience of pain by mammals; the numerous other subjective experiences mammals can have; adjunct physiological responses to pain; some general feature of behavioural responses to pain; and the neural bases of sensations generated within the mouth. Mouth pain in horses is then discussed. The areas considered exclude dental disease, but they include the stimulation of pain receptors by bits in the interdental space, the tongue, the commissures of the mouth, and the buccal mucosa. Compression, laceration, inflammation, impeded tissue blood flow, and tissue stretching are evaluated as noxious stimuli. The high pain sensitivity of the interdental space is described, as are likely increases in pain sensitivity due to repeated bit contact with bruises, cuts, tears, and/or ulcers wherever they are located in the mouth. Behavioural indices of mouth pain are then identified by contrasting the behaviours of horses when wearing bitted bridles, when changed from bitted to bit-free bridles, and when free-roaming unbitted in the wild. Observed indicative behaviours involve mouth movements, head-neck position, and facial expression (“pain face”), as well as characteristic body movements and gait. The welfare impacts of bit-related pain include the noxiousness of the pain itself as well as likely anxiety when anticipating the pain and fear whilst experiencing it, especially if the pain is severe. In addition, particular mouth behaviours impede airflow within the air passages of the upper respiratory system, effects that, in their turn, adversely affect the air passages in the lungs. Here, they increase airflow resistance and decrease alveolar gas exchange, giving rise to suffocating experiences of breathlessness. In addition, breathlessness is a likely consequence of the low jowl angles commonly maintained during dressage. If severe, as with pain, the prospect of breathlessness is likely to give rise to anxiety and the direct experience of breathlessness to fear. The related components of welfare compromise therefore likely involve pain, breathlessness, anxiety, and fear. Finally, a 12-point strategy is proposed to give greater impetus to a wider adoption of bit-free bridles in order to avoid bit-induced mouth pain.
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Affiliation(s)
- David J Mellor
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, Palmerston North 4474, New Zealand
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15
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Mellor DJ, Burns M. Using the Five Domains Model to develop welfare assessment guidelines for Thoroughbred horses in New Zealand. N Z Vet J 2020; 68:150-156. [PMID: 31973682 DOI: 10.1080/00480169.2020.1715900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This review outlines the processes followed by New Zealand Thoroughbred Racing (NZTR) when developing its Thoroughbred Welfare Assessment Guidelines. It accepted that guidance on welfare management must be based on up-to-date knowledge of how animal welfare is understood scientifically. NZTR established an expert panel to facilitate this process. First, major changes in animal welfare science thinking over the last 40 years were considered. For example, the separate biological function and affective state orientations were later accepted as dynamically interacting elements within the body operating as an integrated whole entity; conceptual problems with the Five Freedoms framework led to the formulation of the Five Provisions and Welfare Aims paradigm and development of the Five Domains Model for assessing nutritional, environmental, health, behavioural and mental facets of animal welfare; and the initial major focus on negative experiences evolved to include both negative and positive experiences. The Five Domains Model was very effective for illustrating up-to-date understanding of animal welfare and its use demonstrated how comprehensive animal welfare assessments may be conducted. The NZTR panel followed a sequential approach that included an update on animal welfare thinking and the Five Provisions and Welfare Aims paradigm; the generic Five Domains Model was refocused specifically on equids; a detailed model assessment of equine welfare practices was conducted; enhanced equine welfare practices were emphasised by comparing them to inadequate welfare practices; guidelines were framed in terms which provide domain-specific advice on provisions that achieve positive welfare; other domain-specific guidelines were focused on welfare-compromising consequences of inadequate provisions; and welfare-appropriate conditions were clarified for all stages of a Thoroughbred's life cycle (in work and rest) to facilitate exercising a life-long duty of care. Finally, the guidelines were expressed in general terms to avoid them becoming overly detailed and unwieldy. They therefore do not address specific welfare issues such as use of whips, bits, spurs and tight nosebands, however the Five Domains Model may also be used for these specific purposes. The guidelines, and the way they were formulated, provide an example of one approach which other organisations may find immediately useful, or which may stimulate them to devise their own approaches when progressing such equine welfare initiatives.
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Affiliation(s)
- D J Mellor
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - M Burns
- New Zealand Thoroughbred Racing, Wellington, New Zealand
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Tarazona AM, Ceballos MC, Broom DM. Human Relationships with Domestic and Other Animals: One Health, One Welfare, One Biology. Animals (Basel) 2019; 10:E43. [PMID: 31878310 PMCID: PMC7022888 DOI: 10.3390/ani10010043] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/02/2019] [Accepted: 12/20/2019] [Indexed: 12/18/2022] Open
Abstract
Excessive human population growth, uncontrolled use of natural resources, including deforestation, mining, wasteful systems, biodiversity reduction by agriculture, and damaging climate change affect the existence of all animals, including humans. This discussion is now urgent and people are rethinking their links with the animals we use for clothing, food, work, companionship, entertainment, and research. The concepts of one health, one welfare, and one biology are discussed as a background to driving global change. Nothing should be exploited without considering the ethics of the action and the consequences. This review concerns domesticated animals, including those used for human consumption of meat, eggs, and milk; horses kept for work; and dogs kept for company. Animal welfare includes health, emotional state, and comfort while moving and resting, and is affected by possibilities to show behavior and relationships with others of the same species or with humans. We show some examples of the relations between humans and domesticated animals in the environmental context, including zoonotic diseases, and consider the consequences and the new paradigms resulting from current awareness.
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Affiliation(s)
- Ariel M Tarazona
- Facultad de Ciencias Agrarias, Departamento de Producción Animal Medellín, Universidad Nacional de Colombia, Antioquia 050034, Colombia
| | - Maria C Ceballos
- Grupo ETCO, Group of Studies and Research in Animal Ethology and Ecology, Jaboticabal-SP 14884-900, Brazil;
- Swine Teaching and Research Center, Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348, USA
| | - Donald M Broom
- St Catharine’s College and Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK;
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Mellor DJ. Welfare-aligned Sentience: Enhanced Capacities to Experience, Interact, Anticipate, Choose and Survive. Animals (Basel) 2019; 9:E440. [PMID: 31337042 PMCID: PMC6680886 DOI: 10.3390/ani9070440] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/06/2019] [Accepted: 07/10/2019] [Indexed: 12/14/2022] Open
Abstract
The focus of this opinion is on the key features of sentience in animals which can experience different states of welfare, encapsulated by the new term 'welfare-aligned sentience'. This term is intended to exclude potential forms of sentience that do not enable animals in some taxa to have the subjective experiences which underlie different welfare states. As the scientific understanding of key features of sentience has increased markedly during the last 10 to 15 years, a major purpose here is to provide up-to-date information regarding those features. Eleven interconnected statements about sentience-associated body functions and behaviour are therefore presented and explained briefly. These statements are sequenced to provide progressively more information about key scientifically-supported attributes of welfare-aligned sentience, leading, in their entirety, to a more comprehensive understanding of those attributes. They are as follows: (1) Internal structure-function interactions and integration are the foundations of sentience; (2) animals posess a capacity to respond behaviourally to a range of sensory inputs; (3) the more sophisticated nervous systems can generate subjective experiences, that is, affects; (4) sentience means that animals perceive or experience different affects consciously; (5) within a species, the stage of neurobiological development is significant; (6) during development the onset of cortically-based consciousness is accompanied by cognitively-enhanced capacities to respond behaviourally to unpredictable postnatal environments; (7) sentience includes capacities to communicate with others and to interact with the environment; (8) sentience incorporates experiences of negative and positive affects; (9) negative and positive affective experiences 'matter' to animals for various reasons; (10) acknowledged obstacles inherent in anthropomorphism are largely circumvented by new scientific knowledge, but caution is still required; and (11) there is increasing evidence for sentience among a wider range of invertebrates. The science-based explanations of these statements provide the foundation for a brief definition of 'welfare-aligned sentience', which is offered for consideration. Finally, it is recommended that when assessing key features of sentience the same emphasis should be given to positive and negative affective experiences in the context of their roles in, or potential impacts on, animal welfare.
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Affiliation(s)
- David J Mellor
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, Palmerston North 4442, New Zealand.
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Cook WR, Kibler M. Behavioural assessment of pain in 66 horses, with and without a bit. EQUINE VET EDUC 2018. [DOI: 10.1111/eve.12916] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- W. R. Cook
- Department of Clinical Sciences Cummings School of Veterinary Medicine Tufts University North Grafton Massachusetts USA
| | - M. Kibler
- Department of Mathematics and Computer Science Washington College Chestertown Maryland USA
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Operational Details of the Five Domains Model and Its Key Applications to the Assessment and Management of Animal Welfare. Animals (Basel) 2017; 7:ani7080060. [PMID: 28792485 PMCID: PMC5575572 DOI: 10.3390/ani7080060] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/03/2017] [Accepted: 08/05/2017] [Indexed: 01/15/2023] Open
Abstract
Simple Summary The Five Domains Model is a focusing device to facilitate systematic, structured, comprehensive and coherent assessment of animal welfare; it is not a definition of animal welfare, nor is it intended to be an accurate representation of body structure and function. The purpose of each of the five domains is to draw attention to areas that are relevant to both animal welfare assessment and management. This paper begins by briefly describing the major features of the Model and the operational interactions between the five domains, and then it details seven interacting applications of the Model. These underlie its utility and increasing application to welfare assessment and management in diverse animal use sectors. Abstract In accord with contemporary animal welfare science understanding, the Five Domains Model has a significant focus on subjective experiences, known as affects, which collectively contribute to an animal’s overall welfare state. Operationally, the focus of the Model is on the presence or absence of various internal physical/functional states and external circumstances that give rise to welfare-relevant negative and/or positive mental experiences, i.e., affects. The internal states and external circumstances of animals are evaluated systematically by referring to each of the first four domains of the Model, designated “Nutrition”, “Environment”, “Health” and “Behaviour”. Then affects, considered carefully and cautiously to be generated by factors in these domains, are accumulated into the fifth domain, designated “Mental State”. The scientific foundations of this operational procedure, published in detail elsewhere, are described briefly here, and then seven key ways the Model may be applied to the assessment and management of animal welfare are considered. These applications have the following beneficial objectives—they (1) specify key general foci for animal welfare management; (2) highlight the foundations of specific welfare management objectives; (3) identify previously unrecognised features of poor and good welfare; (4) enable monitoring of responses to specific welfare-focused remedial interventions and/or maintenance activities; (5) facilitate qualitative grading of particular features of welfare compromise and/or enhancement; (6) enable both prospective and retrospective animal welfare assessments to be conducted; and, (7) provide adjunct information to support consideration of quality of life evaluations in the context of end-of-life decisions. However, also noted is the importance of not overstating what utilisation of the Model can achieve.
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