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Massie S, Bayly W, Ohmura H, Takahashi Y, Mukai K, Léguillette R. Field-training in young two-year-old thoroughbreds: investigating cardiorespiratory adaptations and the presence of exercise induced pulmonary hemorrhage. BMC Vet Res 2024; 20:159. [PMID: 38671428 PMCID: PMC11046817 DOI: 10.1186/s12917-024-03997-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 03/28/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Comparatively little is known regarding the initial cardiorespiratory response of young racehorses to training. The objectives were to compare physiological parameters before and after introductory training and determine whether young Thoroughbreds show endoscopic signs of exercise-induced pulmonary hemorrhage (EIPH). Ten Thoroughbreds (20-23 months) underwent 12-weeks of introductory training, including weekly speed sessions. Two 600 m high-speed exercise tests (HSET) were performed following weeks 4 and 12 while wearing a validated ergospirometry facemask. Peak oxygen consumption (V̇O2pk) and ventilatory parameters (tidal volume, VT; peak inspiratory and expiratory flow, PkV̇I, PkV̇E; respiratory frequency, Rf; minute ventilation, V̇E) were measured. The ventilatory equivalent of oxygen (V̇E/V̇O2) and the aerobic and anaerobic contributions to energy production were calculated. Maximal heart rate (HRmax) and HR at maximal speed (HRVmax) were determined. Post-exercise hematocrit, plasma ammonia and blood lactate were measured. Evidence of EIPH was investigated via tracheobronchoscopy post-exercise. Results were compared (paired t-test, P < 0.05). RESULTS Horses were faster following training (P < 0.001) and V̇O2pk increased 28 ml/(kg total mass.min) (28 ± 16%; P < 0.001). Ventilatory (V̇E, P = 0.0015; Rf, P < 0.001; PkV̇I, P < 0.001; PkV̇E, P < 0.001) and cardiovascular parameters (HRmax, P = 0.03; HRVmax, P = 0.04) increased. The increase in V̇E was due to greater Rf, but not VT. V̇E/V̇O2 was lower (26 ± 3.6 vs 23 ± 3.7; P = 0.02), indicating improved ventilatory efficiency. Anaerobic contribution to total energy production increased from 15.6 ± 6.1% to 18.5 ± 6.3% (P = 0.02). Post-exercise hematocrit (P < 0.001), plasma ammonia (P = 0.03) and blood lactate (P = 0.001) increased following training. Horses showed no signs of EIPH. CONCLUSIONS Young two-year-old Thoroughbreds responded well to introductory training without developing tracheobronchoscopic evidence of EIPH.
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Affiliation(s)
- Shannon Massie
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4Z6, Canada
| | - Warwick Bayly
- College of Veterinary Medicine, Washington State University, Grimes Way, Pullman, WA, 99164, USA
| | - Hajime Ohmura
- Equine Research Institute, Japan Racing Association, 1400-4, Shiba, Shimotsuke-shi, Tochigi, 329-0412, Japan
| | - Yuji Takahashi
- Equine Research Institute, Japan Racing Association, 1400-4, Shiba, Shimotsuke-shi, Tochigi, 329-0412, Japan
| | - Kazutaka Mukai
- Equine Research Institute, Japan Racing Association, 1400-4, Shiba, Shimotsuke-shi, Tochigi, 329-0412, Japan
| | - Renaud Léguillette
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4Z6, Canada.
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Katz LM, Gough K, McGivney CL, McGivney B, Sides RH, Hill EW, Bayly WM. Comparison of ventilatory and oxygen consumption measurements of yearling Thoroughbred colts and fillies exercising unridden on an all-weather track. Vet J 2023; 300-302:106041. [PMID: 37931872 DOI: 10.1016/j.tvjl.2023.106041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/31/2023] [Accepted: 11/02/2023] [Indexed: 11/08/2023]
Abstract
Sex effects on ventilatory and oxygen consumption (V̇O2) measurements during exercise have been identified in humans. This study's aim was to evaluate the hypothesis that there are sex effects on ventilatory and V̇O2 measurements in exercising, untrained yearling Thoroughbreds (Tb). Forty-one Tbs (16 colts, 25 fillies; 19.8 ± 1.4 months old) were recruited. Physiological, ventilatory and exercise data were gathered from horses exercising unridden at high intensity on an all-weather track from a global positioning-heart rate unit and a portable ergospirometry system. Data were analysed with an unpaired Student's t-test and the Benjamini-Hochberg correction for multiple testing (P ≤ 0.05 significant). Mean bodyweight (BW, P = 0.002) and wither height (P = 0.04) were greater for colts than fillies. There were no differences in physiological and exercise data and absolute peak V̇O2 between groups. However, fillies had a higher mass specific peak V̇O2 (P = 0.03) than colts (121.5 ± 21.6 mL/kg.min vs. 111.9 ± 27.4 mL/kg.min). The peak breathing frequency was greater for fillies (P < 0.001) while the peak inspiratory (P < 0.001) and expiratory air flow (P < 0.001), peak expiratory tidal volume (VTE; P < 0.001) and peak minute ventilation (V̇E; P = 0.01) were greater for colts; there were no differences for peak VTE and V̇E when adjusted for BW. Differences in BW explain the differences in mass specific peak V̇O2 between groups. Given their morphological differences, it is likely that lung volumes and airway diameters are smaller for fillies, resulting in greater resistance and lower air flows and volumes. Further research is required to investigate the ventilatory differences and how they may change with maturation and impact performance.
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Affiliation(s)
- L M Katz
- UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin D04 W6F6, Ireland.
| | - K Gough
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin D04 W6F6, Ireland
| | - C L McGivney
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin D04 W6F6, Ireland
| | - B McGivney
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin D04 W6F6, Ireland
| | - R H Sides
- Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA 99164-6610, USA
| | - E W Hill
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin D04 W6F6, Ireland
| | - W M Bayly
- Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA 99164-6610, USA
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Lean NE, Bertin FR, Ahern BJ. Influence of unilateral and bilateral vocal cordectomy on airflow across cadaveric equine larynges at different Rakestraw grades of arytenoid abduction. Vet Surg 2022; 51:974-981. [PMID: 35608018 PMCID: PMC9546136 DOI: 10.1111/vsu.13823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 03/20/2022] [Accepted: 04/15/2022] [Indexed: 11/26/2022]
Abstract
Objective To assess the effect of vocal cordectomy on airflow across equine larynges at different Rakestraw grades of arytenoid abduction using a unidirectional airflow model. Study design Ex vivo, repeated measures. Sample population Twenty cadaveric equine larynges. Methods The right arytenoid cartilage was maximally abducted in all larynges. Each larynx was assigned a Rakestraw grade A or B, and the left arytenoid was abducted accordingly. Each larynx was tested under 3 conditions: intact, left vocal cordectomy (LVC), and bilateral vocal cordectomy (BVC). Translaryngeal pressure and airflow were measured, and digital video footage was obtained. Translaryngeal impedance (TLI) was calculated, and the arytenoid left‐to‐right quotient angle (LRQ) and rima glottis cross‐sectional area (CSA) were measured from standardized still images. Results Vocal cordectomy reduced TLI by 14.5% in LVC in comparison with intact larynges at Rakestraw grade B (P = .014). In Rakestraw grade A position, neither unilateral nor bilateral vocal cordectomy had any effect on TLI. Regardless of Rakestraw allocation, both LVC and BVC increased CSA in comparison with intact larynges (P < .005), with BVC larynges experiencing a greater effect than LVC (P < .0001). Conclusion Using a unilateral airflow model, LVC improved TLI in larynges where arytenoid position approximated Rakestraw grade B. However, when the arytenoid position approximated Rakestraw grade A, there was no effect on TLI following LVC or BVC. Clinical significance Surgeons considering a vocal cordectomy should take into account the degree of arytenoid abduction before performing the procedure, as it may not be warranted from a TLI point of view.
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Affiliation(s)
- Natasha E Lean
- School of Veterinary Science, University of Queensland, Gatton, Queensland
| | - Francois R Bertin
- School of Veterinary Science, University of Queensland, Gatton, Queensland
| | - Benjamin J Ahern
- School of Veterinary Science, University of Queensland, Gatton, Queensland
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Oliveira T, Bogossian P, Hilgert A, Fernandes W. Use of external nasal strip influences alveolar cell population of horses after exercise. ARQ BRAS MED VET ZOO 2021. [DOI: 10.1590/1678-4162-12325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT The nasal strip is widely used in horses during exercise, but effects of using a nasal strip are controversial and little is known about its effect on horses undergoing endurance events. The aim of this study was to determine whether the use of nasal strips influences alveolar cell population assessed by bronchoalveolar lavage (BAL), tidal volume, and nasal airflow rate. Six Arabian horses were subjected to two low intensity tests on a treadmill, with and without application of a commercial external nasal strip. Tidal volumes and airflow rates were measured during the test; two hours after the test, BAL was performed to assess cytology of pulmonary secretions. The lavage fluid showed increased neutrophil count after exercise in animals with the nasal strip (P<0.05). This suggests that turbulence of airflow through the nasal cavity may have diminished with nasal strip use, thus allowing larger particles to be deposited more distally in the respiratory system, inducing a more intense neutrophilic response. No differences in tidal volumes or airflow rates were observed between groups (with or without nasal strips) during the test (P>0.05). The use of nasal strips seems to influence alveolar cell population during and after exercise in horses after low intensity exercise tests. Further studies are needed to verify whether alveolar cell population is related to poor exercise performance in horses.
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Ahern BJ, Lukas E, Lam K, Wilke E, Bertin FR, Van Eps A, Franklin S. Evaluation of a prototype dynamic laryngoplasty system in vitro with an equine vacuum airflow system. Vet Surg 2018; 48:173-179. [PMID: 30569487 DOI: 10.1111/vsu.13137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 04/09/2018] [Accepted: 05/29/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate a prototype dynamic laryngoplasty system (DLPS) in a static airflow model. STUDY DESIGN Experimental. SAMPLE POPULATION Ten equine larynges. METHODS The right arytenoid was fixed in abduction in all specimens. A left-sided laryngoplasty was performed with No. 2 Fiberwire and a FASTakII anchor. Each larynx was tested in a static airflow model. The system was adjusted to a flow rate of 55 L/s and prelaryngeal pressure of 12 mm Hg prior to testing in maximal arytenoid abduction. In phase 1, the left suture was loosened, shortened, and tested in 3-mm steps from 0 to 30 mm. In phase 2, the suture was tied with the DLPS in position at a target left-to-right quotient angle (LRQ) of 0.5. The DLPS was activated to target psi of 0, 25, and 50 for testing. Translaryngeal impedance (TLI), LRQ, cross-sectional areas (CSA), and resultant change in LRQ and CSA between, before, and during airflow testing were calculated. RESULTS In phase 1, TLI was reduced by suture shortening up to 6 mm (P = .001) but not by additional shortening (P > .05). In phase 2, activation of the DLPS reduced the TLI from 0 psi (0.43 ± 0.08 mm Hg/L/s) to 25 psi (0.16 ± 0.04 mm Hg/L/s, P < .001), but no further reduction was detected at maximal psi (P = .10). CONCLUSION Activation of the DLPS effectively reduced TLI. CLINICAL SIGNIFICANCE These results justify further investigation of the DLPS to assess its clinical applicability.
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Affiliation(s)
- Benjamin J Ahern
- Equine Specialist Hospital, School of Veterinary Science, University of Queensland, UQ Gatton Campus, Gatton, Queensland, Australia
| | - Emily Lukas
- Equine Specialist Hospital, School of Veterinary Science, University of Queensland, UQ Gatton Campus, Gatton, Queensland, Australia
| | - Kimberly Lam
- Equine Specialist Hospital, School of Veterinary Science, University of Queensland, UQ Gatton Campus, Gatton, Queensland, Australia
| | - Emma Wilke
- Equine Specialist Hospital, School of Veterinary Science, University of Queensland, UQ Gatton Campus, Gatton, Queensland, Australia
| | - Francois-Rene Bertin
- Equine Specialist Hospital, School of Veterinary Science, University of Queensland, UQ Gatton Campus, Gatton, Queensland, Australia
| | - Andrew Van Eps
- Equine Specialist Hospital, School of Veterinary Science, University of Queensland, UQ Gatton Campus, Gatton, Queensland, Australia
| | - Samantha Franklin
- Equine Health and Performance Centre, University of Adelaide, Roseworthy, South Australia, Australia
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Sides RH, Kirkpatrick R, Renner E, Gough K, Katz LM, Evans DL, Bayly WM. Validation of masks for determination of V̇O 2 max in horses exercising at high intensity. Equine Vet J 2017. [PMID: 28627036 DOI: 10.1111/evj.12711] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The need for a horse to be ridden while wearing a measurement device that allows unrestricted ventilation and gas exchange has hampered accurate measurement of its maximal oxygen consumption (V̇O2 max) under field conditions. OBJECTIVES Design and validate a facemask with the potential to measure V̇O2 max accurately in the field. STUDY DESIGN Experiment with 6 × 6 Latin square design. METHODS Two variations of a mask and associated electronic control module (ECM) were designed to enable breath-by-breath measurement of airflows through two 7.8 cm diameter pneumotachometers located 7.5 cm in front of each narus. The ECM was comprised of an analogue-to-digital converter and a lithium-ion battery that provided power and signal filtering to the pneumotachometers and an oxygen sensing cell, and powered a pump connected to gas sampling ports between the nares and pneumotachometers. Airflow and oxygen content of inspired and expired gases were recorded through the ECM and electronically transferred to a notebook. V̇O2 was determined from these recordings using a customised software program. Mask B encased the lower jaw. Mask R left the jaw free so the horse could wear a bit if ridden. V̇O2 max and arterial blood gases were measured in 6 horses during multiple treadmill tests. Each mask was worn twice and results compared to those from an established open flow-through system (O) by ANOVA-RM (P<0.05). System utility was evaluated using the intraclass correlation coefficient of 4 independent raters. RESULTS Blood gases and V̇O2 max (151.9±7.0 [mean±s.d.; O], 151.5±9.6 [B], 149.5±7.5 [R] ml/[kg.min]) were not different between masks. V̇O2 max measures were reproducible for each mask. Intraclass correlation coefficient between raters = 0.99. MAIN LIMITATIONS Some rebreathing of expired air from mask dead space. CONCLUSION Masks capable of measuring V̇O2 max during treadmill exercise were developed, tested and found to be accurate. Mask R has potential application to measurement of V̇O2 max under field conditions.
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Affiliation(s)
- R H Sides
- Department of Veterinary Clinical Sciences, Washington State University, Pullman, Washington, USA
| | - R Kirkpatrick
- Department of Veterinary Clinical Sciences, Washington State University, Pullman, Washington, USA
| | - E Renner
- Department of Veterinary Clinical Sciences, Washington State University, Pullman, Washington, USA
| | - K Gough
- University College Dublin, Belfield, Dublin, Ireland
| | - L M Katz
- University College Dublin, Belfield, Dublin, Ireland
| | - D L Evans
- Faculty of Veterinary Science, University of Sydney, Sydney, Australia
| | - W M Bayly
- Department of Veterinary Clinical Sciences, Washington State University, Pullman, Washington, USA
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Burnheim K, Hughes KJ, Evans DL, Raidal SL. Reliability of breath by breath spirometry and relative flow-time indices for pulmonary function testing in horses. BMC Vet Res 2016; 12:268. [PMID: 27894292 PMCID: PMC5126818 DOI: 10.1186/s12917-016-0893-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/21/2016] [Indexed: 11/23/2022] Open
Abstract
Background Respiratory problems are common in horses, and are often diagnosed as a cause of poor athletic performance. Reliable, accurate and sensitive spirometric tests of airway function in resting horses would assist with the diagnosis of limitations to breathing and facilitate investigations of the effects of various treatments on breathing capacity. The evaluation of respiratory function in horses is challenging and suitable procedures are not widely available to equine practitioners. The determination of relative flow or flow-time measures is used in paediatric patients where compliance may limit conventional pulmonary function techniques. The aim of the current study was to characterise absolute and relative indices of respiratory function in healthy horses during eupnoea (tidal breathing) and carbon dioxide (CO2)-induced hyperpnoea (rebreathing) using a modified mask pneumotrachographic technique well suited to equine practice, and to evaluate the reliability of this technique over three consecutive days. Coefficients of variation, intra-class correlations, mean differences and 95% confidence intervals across all days of testing were established for each parameter. Results The technique provided absolute measures of respiratory function (respiratory rate, tidal volume, peak inspiratory and expiratory flows, time to peak flow) consistent with previous studies and there was no significant effect of day on any measure of respiratory function. Variability of measurements was decreased during hyperpnea caused by rebreathing CO2, but a number of relative flow-time variables demonstrated good agreement during eupnoeic respiration. Conclusions The technique was well tolerated by horses and study findings suggest the technique is suitable for evaluation of respiratory function in horses. The use of relative flow-time variables provided reproducible (consistent) results, suggesting the technique may be of use for repeated measures studies in horses during tidal breathing or rebreathing. Electronic supplementary material The online version of this article (doi:10.1186/s12917-016-0893-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- K Burnheim
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, 2650, NSW, Australia
| | - K J Hughes
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, 2650, NSW, Australia
| | - D L Evans
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, 2650, NSW, Australia
| | - S L Raidal
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, 2650, NSW, Australia.
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Allen KJ, van Erck-Westergren E, Franklin SH. Exercise testing in the equine athlete. EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- K. J. Allen
- Equine Sports Medicine Centre; University of Bristol; Langford UK
| | | | - S. H. Franklin
- School of Animal and Veterinary Sciences; University of Adelaide; Roseworthy South Australia Australia
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RAMSEYER A, SIDES R, SLINKER B, EVANS D, BAYLY W. Evaluation of a mask for breath-by-breath respirometry during exercise in horses. Equine Vet J 2010:240-5. [DOI: 10.1111/j.2042-3306.2010.00250.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Evans DL, Kiddell L, Smith CL. Pulmonary function measurements immediately after exercise are correlated with neutrophil percentage in tracheal aspirates in horses with poor racing performance. Res Vet Sci 2010; 90:510-5. [PMID: 20678784 DOI: 10.1016/j.rvsc.2010.07.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 07/07/2010] [Accepted: 07/09/2010] [Indexed: 11/29/2022]
Abstract
Inflammatory airway disease (IAD) is common in racehorses, and is a cause of wastage in the industry. IAD has been diagnosed by measurement of percent neutrophils (N%) in tracheal aspirates (TA). The aim of this study was to investigate whether spirometric indices of pulmonary function were correlated with N% in TAs. Limits to breathing were measured by analyses of relationships between relative times and relative respiratory gas flows during inspiration and expiration in individual breaths recorded after exercise. Horses with higher N% had significantly lower relative gas flows at the same relative times during inspiration and expiration, suggesting a limit to breathing. These findings confirm a physiological basis for the measurement of N% in TA after exercise for diagnosis of IAD. Spirometric pulmonary function testing using analyses of individual breaths after exercise has application for assessment of pulmonary function and poor exercise performance.
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Affiliation(s)
- D L Evans
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia.
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11
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Curtis RA, Kusano K, Evans DL. Observations on respiratory flow strategies during and after intense treadmill exercise to fatigue in Thoroughbred racehorses. Equine Vet J 2010:567-72. [PMID: 17402485 DOI: 10.1111/j.2042-3306.2006.tb05606.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
REASONS FOR PERFORMING STUDY Locomotor-respiratory coupled (LRC) breath types are a feature of galloping exercise in horses. Differences in breath type have been demonstrated during exercise in particular the 'big respiratory cycle' (BRC) and 'flow hesitation'. To investigate breath types during recovery and quantitatively investigate BRCs during exercise to understanding the mechanism driving BRCs. OBJECTIVES To investigate the occurrence of different breath types during and after intense treadmill exercise, and test the hypothesis that large breaths (BRCs) were a function of respiratory frequency. METHODS Six trained and clinically normal Thoroughbred horses were exercise tested on a treadmill (slope 10%). Breath-by-breath pulmonary ventilation was measured continuously during exercise and recovery using a Quadflow mask. RESULTS Five different breath types were identified, and classified as normal monophasic, normal biphasic, deglutition, effort pause, or large breaths. Exercising at 10 m/sec, the number of large breaths was significantly related to Rf (r = -0.86, P = 0.03). During 120 sec after exercise there were 2 distinct populations of breaths, large and normal monophasic. CONCLUSIONS BRC type breaths are a normal feature of ventilation during and after intense exercise. In recovery there are two distinct breath populations. During exercise BRC frequency is inversely associated with respiratory frequency and highly dependant on the individual horse. From intense exercise to recovery, high flow rates and LRC limited tidal volumes are replaced by high tidal volumes and progressively decreasing flow rates. There is a temporal association between BRC occurrence and PECO2. POTENTIAL RELEVANCE Breath types and the physiological mechanism for driving each type is important in the clinical interpretation of respiratory disease or dysfunction. The demonstration of BRC association with PECO2 may help understand the driving mechanism for the BRC. In pulmonary function testing, breath type is important in quantitative results. The demonstration that high tidal flows with limited tidal volumes during intense exercise being replaced by high tidal volumes and progressively decreasing flows in recovery has potential clinical relevance.
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Affiliation(s)
- R A Curtis
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia
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12
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Abstract
The objective of this research was to develop a non-invasive method to detect an emotional response of a horse to novelty during physical activity. Two horses performed 20 trials each, in which the horse's heart rate (HR) and physical activity were continuously measured. The relationship between the horse's physical activity and HR was described by a mathematical model allowing online decomposition of the horse's HR into a physical component and a component containing information about its emotional state. Exposure to the novel object resulted in an increase in the emotional component of HR, which allowed automatic detection of an emotional response of the horse in 33/40 trials. In the remaining seven trials no stable model could be built or data were missing. The results show that model-based decomposition of HR can be a useful tool for quantification of certain aspects of temperament.
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13
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Rakesh V, Rakesh NG, Datta AK, Cheetham J, Pease AP. Development of equine upper airway fluid mechanics model for Thoroughbred racehorses. Equine Vet J 2008; 40:272-9. [PMID: 18290260 DOI: 10.2746/042516408x281216] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASON FOR PERFORMING STUDY Computational fluid dynamics (CFD) models provide the means to evaluate airflow in the upper airways without requiring in vivo experiments. HYPOTHESIS The physiological conditions of a Thoroughbred racehorse's upper airway during exercise could be simulated. METHODS Computed tomography scanned images of a 3-year-old intact male Thoroughbred racehorse cadaver were used to simulate in vivo geometry. Airway pressure traces from a live Thoroughbred horse, during exercise was used to set the boundary condition. Fluid-flow equations were solved for turbulent flow in the airway during inspiratory and expiratory phases. The wall pressure turbulent kinetic energy and velocity distributions were studied at different cross-sections along the airway. This provided insight into the general flow pattern and helped identify regions susceptible to dynamic collapse. RESULTS The airflow velocity and static tracheal pressure were comparable to data of horses exercising on a high-speed treadmill reported in recent literature. The cross-sectional area of the fully dilated rima glottidis was 7% greater than the trachea. During inspiration, the area of highest turbulence (i.e. kinetic energy) was in the larynx, the rostral aspect of the nasopharynx was subjected to the most negative wall pressure and the highest airflow velocity is more caudal on the ventral aspect of the nasopharynx (i.e. the soft palate). During exhalation, the area of highest turbulence was in the rostral and mid-nasopharynx, the maximum positive pressure was observed at the caudal aspect of the soft palate and the highest airflow velocity at the front of the nasopharynx. CONCLUSIONS AND CLINICAL RELEVANCE In the equine upper airway collapsible area, the floor of the rostral aspect of the nasopharynx is subjected to the most significant collapsing pressure with high average turbulent kinetic during inhalation, which may lead to palatal instability and explain the high prevalence of dorsal displacement of the soft palate (DDSP) in racehorses. Maximal abduction of the arytenoid cartilage may not be needed for optimal performance, since the trachea cross-sectional area is 7% smaller than the rima glottidis.
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Affiliation(s)
- V Rakesh
- Department of Biological and Environmental Engineering, College of Agriculture and Life Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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14
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Abstract
This review addresses the physiology of performance horses in the context of functional tests aimed at assisting clinicians in the search for explanations of the individual's limitations, actual or perceived as below expectation. The intention is to assist clinicians who are faced frequently by owners or trainers seeking explanations for poor performance; and for research workers as a basis on which to proceed in their search for new methodologies, particularly those that can be applied in the field as for treadmill exercise. The review sets out fundamental physiological pathways, the entailment of which may represent a limiting factor to performance, while taking into account the individual's status, including anamnesis and the possibility of actual disease being present. Tests that assess the possible roles of several body systems, as causes of limited performance, are discussed. These systems include pulmonary, cardiovascular and neuromuscular systems. The evaluation of anaerobic and aerobic energy pathways is also discussed. Emphasis is given to the assessment of pulmonary ventilation by techniques such as spirometry and ergospirometry. These techniques are considered to be of particular potential for further development.
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Affiliation(s)
- D L Evans
- Faculty of Veterinary Science, The University of Sydney, New South Wales 2006, Australia
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15
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Kusano K, Curtis R, Goldman C, Evans D. Relative Flow-Time Relationships in Single Breaths Recorded After Treadmill Exercise in Thoroughbred Horses. J Equine Vet Sci 2007. [DOI: 10.1016/j.jevs.2007.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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