Thermoregulation. Base mechanisms and hyperthermia.
Abstract: Metabolic HP is extremely high during exercise in horses. Thermoregulation in horses is primarily dependent on evaporative heat loss from sweating in particular. Under thermoneutral conditions, these mechanisms are sufficient to allow horses to perform high-intensity exercise for long periods. Under thermally stressful conditions, particularly in high ambient humidity, the efficiency of evaporative heat loss mechanisms is compromised and may result in horses developing hyperthermia. Early recognition and vigorous treatment are essential to limit the consequences of heat stress in horses. Meticulous planning and management of equestrian events that are held under thermally stressful conditions are essential to ensure the welfare of competing horses and their riders. The conditioning program of horses expected to compete under thermally stressful conditions must also make adequate provision for acclimatization to the hot, humid conditions.
Publication Date: 1998-04-30 PubMed ID: 9561687DOI: 10.1016/s0749-0739(17)30211-0Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Review
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research article explores the reliance of horses on sweating for thermoregulation, especially during high-intensity exercise. It highlights that extreme heat or high humidity can compromise this mechanism, possibly leading to hyperthermia, therefore stressing the need for early identification, rigorous treatment, and careful management of equestrian events under such conditions.
Understanding horse thermoregulation
- The study demonstrates that horses’ thermoregulation primarily depends on evaporative heat loss from sweating. This process is highly effective under thermoneutral conditions, allowing the animals to engage in intensive exercise for extended periods.
- The metabolic heat production (HP) of these animals increases significantly during exercise. Their bodies are able to efficiently manage this heat through their sweating mechanism.
Elevated risk during thermally stressful conditions
- In scenarios of high ambient humidity or extreme heat, horses’ thermoregulatory mechanisms become less efficient. These are referred to as thermally stressful conditions.
- Sweating under such conditions becomes less effective in dissipating heat, which can lead to the horses developing hyperthermia, a potentially life-threatening condition characterized by an untypically high body temperature.
The importance of planning and treatment
- The study emphasizes the necessity of early recognition and vigorous treatment when a horse shows signs of heat stress. This intervention is critical in avoiding serious consequences, including physical harm or even death.
- Part of the required measures involves careful planning and management of equestrian events, especially those held under thermally stressful conditions. The welfare of both the horses and their riders must be seriously considered.
Acclimatization to hot and humid conditions
- Finally, the research calls for an adequate conditioning program for horses that are anticipated to compete under thermally stressful conditions.
- Such a program should allow the animals to acclimatize to hot and humid conditions thus better preparing their bodies for effective thermoregulation under these circumstances.
Cite This Article
APA
Guthrie AJ, Lund RJ.
(1998).
Thermoregulation. Base mechanisms and hyperthermia.
Vet Clin North Am Equine Pract, 14(1), 45-59.
https://doi.org/10.1016/s0749-0739(17)30211-0 Publication
Researcher Affiliations
- Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Republic of South Africa.
MeSH Terms
- Animals
- Body Temperature Regulation / physiology
- Fever / physiopathology
- Fever / therapy
- Fever / veterinary
- Horse Diseases / physiopathology
- Horse Diseases / therapy
- Horses / physiology
Citations
This article has been cited 13 times.- Lisboa BRF, da Silva JAR, da Silva WC, Barbosa AVC, Silva LKX, Lourenço-Júnior JB. Evaluation of thermoregulation of horses (Equus caballus) submitted to two methods of post-exercise cooling, in hot and humid climate conditions, in the Eastern Amazon. Front Vet Sci 2023;10:1150763.
- Kang H, Zsoldos RR, Sole-Guitart A, Narayan E, Cawdell-Smith AJ, Gaughan JB. Heat stress in horses: a literature review. Int J Biometeorol 2023 Jun;67(6):957-973.
- Harvey AM, Ramp D, Mellor DJ. Review of the Foundational Knowledge Required for Assessing Horse Welfare. Animals (Basel) 2022 Dec 1;12(23).
- Cox EG, Bell R, Greer RM, Jeffcott LB. A survey on the use of rugs in Australian horses. Aust Vet J 2023 Jan;101(1-2):9-26.
- Kang H, Zsoldos RR, Skinner JE, Gaughan JB, Mellor VA, Sole-Guitart A. The Use of Percutaneous Thermal Sensing Microchips to Measure Body Temperature in Horses during and after Exercise Using Three Different Cool-Down Methods. Animals (Basel) 2022 May 14;12(10).
- Janczarek I, Wiśniewska A, Tkaczyk E, Wnuk-Pawlak E, Kaczmarek B, Liss-Szczepanek M, Kędzierski W. Effect of Different Water Cooling Treatments on Changes in Rectal and Surface Body Temperature in Leisure Horses after Medium-Intensity Effort. Animals (Basel) 2022 Feb 21;12(4).
- Janczarek I, Stachurska A, Wilk I, Wiśniewska A, Różańska-Boczula M, Kaczmarek B, Łuszczyński J, Kędzierski W. Horse Preferences for Insolation, Shade or Mist Curtain in the Paddock under Heat Conditions: Cardiac and Behavioural Response Analysis. Animals (Basel) 2021 Mar 25;11(4).
- Kang H, Zsoldos RR, Woldeyohannes SM, Gaughan JB, Sole Guitart A. The Use of Percutaneous Thermal Sensing Microchips for Body Temperature Measurements in Horses Prior to, during and after Treadmill Exercise. Animals (Basel) 2020 Dec 2;10(12).
- Nomura M, Shiose T, Ishikawa Y, Mizobe F, Sakai S, Kusano K. Prevalence of post-race exertional heat illness in Thoroughbred racehorses and climate conditions at racecourses in Japan. J Equine Sci 2019 Jul;30(2):17-23.
- McGivney BA, McGettigan PA, Browne JA, Evans AC, Fonseca RG, Loftus BJ, Lohan A, MacHugh DE, Murphy BA, Katz LM, Hill EW. Characterization of the equine skeletal muscle transcriptome identifies novel functional responses to exercise training. BMC Genomics 2010 Jun 23;11:398.
- McGivney BA, Eivers SS, MacHugh DE, MacLeod JN, O'Gorman GM, Park SD, Katz LM, Hill EW. Transcriptional adaptations following exercise in thoroughbred horse skeletal muscle highlights molecular mechanisms that lead to muscle hypertrophy. BMC Genomics 2009 Dec 30;10:638.
- Sarubbi J, Martínez-Burnes J, Ghezzi MD, Olmos-Hernandez A, Lendez PA, Ceriani MC, Hernández-Avalos I. Hypothalamic Neuromodulation and Control of the Dermal Surface Temperature of Livestock during Hyperthermia. Animals (Basel) 2024 Jun 9;14(12).
- Verdegaal EJMM, Howarth GS, McWhorter TJ, Delesalle CJG. Thermoregulation during Field Exercise in Horses Using Skin Temperature Monitoring. Animals (Basel) 2023 Dec 30;14(1).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
