07/31/2025
๐ฅ๐ด Heat & Horses: Facts, Prevention & What Actually Works โ๏ธ๐ฆ
Your horse wasnโt built for this. Horses evolved for subzero climatesโnot 95ยฐF Florida humidity with no wind. One mistake in heat management can turn into a life-threatening crisis within minutes.
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๐งฌ Scientific Foundations
โข Horses maintain core temperature between 99.5โ101.5ยฐF, with thermoneutral comfort ending around 86ยฐF. Above that, they rely solely on sweating for coolingโwhich fails in humidity [1].
โข Horses sweat up to 4 gallons per hour, losing electrolytes critical to muscle and nerve function [2].
โข Their low surface-area-to-mass ratio (~1:90 mยฒ/kg vs humans ~1:35) makes them poor at dissipating heat [1].
โข UC Davis notes: RR >40 bpm, delayed return to baseline HR, dry gums, and reduced gut sounds are early heat stress indicators [3].
โข NMSU warns: HR >80, RR >50, or re**al temp >103ยฐF with no drop despite cooling = active heat illness [4].
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๐จ Stages of Heat Injury (TPR Guide)
1๏ธโฃ Heat Stress
Temp: 102.5โ104.5ยฐF | HR: 44โ60 bpm | RR: 40โ60 bpm
Action: Shade, cold hose, airflow, electrolytes
2๏ธโฃ Heat Exhaustion
Temp: 104.5โ105.5ยฐF | HR: 60โ80 bpm | RR: 60โ80 bpm
Action: Aggressive hosing, fan, fluids, call vet
3๏ธโฃ Heat Stroke (Critical)
Temp: โฅ106ยฐF | HR: 80โ120 bpm | RR: 80+ bpm
Action: Cold immersion or saltwater spa, ice packs, rubbing alcohol, vet immediately
[3,4]
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โ ๏ธ Documented Complications
โข Rhabdomyolysis, laminitis, acute renal failure
โข GI stasis, colic, endotoxemia
โข Neurological injury, seizures, permanent anhidrosis
[1,3,4]
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๐ Medications to AVOID in Heat
๐ซ Acepromazine โ vasodilation โ worsens low BP
๐ซ NSAIDs โ risk kidney damage when dehydrated
๐ซ Diuretics/Thyroid meds โ intensify fluid & heat stress
โ
Use vet-supervised fluids, cooling therapies, and antioxidant support
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โ
Proven Supplements for Heat Tolerance
๐ง Electrolytes & Salt
Replaces sweat loss. Loose salt is often better absorbed than blocks. Always offer clean water.
[3,4]
๐ฅ Omega-3 Fatty Acids (EPA/DHA)
Studies show supplementation reduces inflammatory load and oxidative stress during heat and work [5]. Feed fish oil or stabilized flax.
๐งช Vitamin E + Selenium
Peer-reviewed data shows that antioxidant supplementation improves muscle function and immune response under heat stress [6,7]. Most horses on hay alone are deficient.
๐ At our clinic, we recommend daily vitamin E (2,000โ4,000 IU/day), natural-source selenium (1โ3 mg/day depending on diet), and omega-3s to help buffer the inflammatory and metabolic strain of hot weather.
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โ Myths That Put Horses at Risk
โข โCold water causes colicโ โ โ False. UC Davis confirms cold water is safe and helps recovery [3]
โข โDonโt scrape or water traps heatโ โ โ False. Continuous hosing and airflow are what cools [3]
โข โHeโs sweating, so heโs fineโ โ โ Not necessarily. Monitor TPR, not just sweat
โข โFly sheets help in heatโ โ โ Most trap heat unless specifically engineered mesh
โข โHeโs acclimatedโ โ โ Even Florida-born horses collapse from heat stress
โข โElectrolytes fix it allโ โ โ Only if combined with water, airflow, and cooling
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๐ก Real Barn Strategy for Florida Heat
โ๏ธ Fans angled downward from above to pull heat out
โ๏ธ Cross-ventilate using aisle fans
โ๏ธ Wet stall walls, bedding, shedrow, and barn aisles
โ๏ธ Build a swamp cooler (fan + ice or alcohol slush)
โ๏ธ Keep ice packs + rubbing alcohol on hand
โ๏ธ Use a cold saltwater spa to cool core temp and reduce systemic inflammation
โ๏ธ Offer cool water (50โ65ยฐF) and electrolytes
โ๏ธ Supplement daily with omega-3s, vitamin E, and selenium
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๐ง Internal Support: Equine Immune Boost
Our Equine Immune Boost supports heat resilience and immune recovery by enhancing circulation, lowering inflammation, and supporting antioxidant systems.
Especially useful in:
โข Anhidrosis-prone horses
โข Metabolic horses under stress
โข Performance horses in hot weather
Used daily in our rehab and performance horses.
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๐This month alone, weโve managed heat exhaustion, metabolic crashes, and anhidrosis cases in Ocala.
We use cold saltwater spa, HBOT, IV ozone, metabolic therapy, and strategic supplementation.
Cooling isnโt optional. Prevention isnโt a luxury.
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๐ฌ Share this post with your barn team. Hang it in the feed room. Save it for emergency reference.
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๐ References
1. Ohmura, H. et al. Heat stress in horses: A literature review. PMC10267279.
2. Mad Barn Nutrition. Heat Stress in Horses: Causes, Signs, and Prevention.
3. UC Davis Center for Equine Health. Keeping Horses Healthy in Hot Weather. https://ceh.vetmed.ucdavis.edu/health-topics/keeping-horses-healthy-hot-weather
4. New Mexico State University Extension. Recognizing and Treating Heat Stress in Horses. B-711. https://pubs.nmsu.edu/_b/B711
5. Silvestre, A.M. et al. Omega-3 fatty acid supplementation reduces oxidative stress in performance horses. PMC8259830.
6. Canadian Journal of Animal Science. Selenium and Vitamin E for Equine Oxidative Balance. https://cdnsciencepub.com/doi/full/10.1139/cjas-2024-0051
7. BMC Veterinary Research. Antioxidant response to vitamin E and Se in horses under stress. https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-022-03411-4