🩺 Equine Heat Stroke: A 2025 Vet’s Emergency Guide by Dr Duncan Houston BVSc

Meta description: Learn to recognize and treat equine heat stroke—signs, emergency cooling, veterinary care, prevention strategies & Ask A Vet support.

1. 🔥 What Is Heat Stroke?

Heat stroke in horses occurs when the body's cooling mechanisms fail and core temperature surpasses **40.5 °C (105 °F)**. This leads to multi-system collapse—central nervous system, cardiovascular, renal, hepatic and gastrointestinal dysfunction :contentReference[oaicite:3]{index=3}.

2. ⚠️ Why It's a Life‑Threatening Emergency

Untreated, heat stroke causes cellular damage, coagulation disorders, endotoxemia, organ failure, laminitis, colic and potentially death :contentReference[oaicite:4]{index=4}. Rapid intervention within **10–20 minutes** can significantly improve survival :contentReference[oaicite:5]{index=5}.

3. 🩺 Recognizing Clinical Signs

• Rectal temperature: ≥ 40.5 °C (105 °F) = heat stroke :contentReference[oaicite:6]{index=6}.
• Heart rate: >60 bpm; at rest, up to >80 bpm is concerning :contentReference[oaicite:7]{index=7}.
• Respiratory rate: >40 breaths/min, flared nostrils, panting :contentReference[oaicite:8]{index=8}.
• Sweating: excessive, or paradoxically dry, hot coat in severe cases :contentReference[oaicite:9]{index=9}.
• Neurologic signs: incoordination, staggering, agitation, seizures or collapse :contentReference[oaicite:10]{index=10}.
• Dehydration: prolonged skin tent, sunken eyes, tacky gums :contentReference[oaicite:11]{index=11}.
• Behavioral change: dullness, irritability or panic :contentReference[oaicite:12]{index=12}.

4. 🆘 Immediate First Aid

If your horse shows early heat stress signs, act fast:

• Stop exercise, remove tack, move to cool shade or breeze :contentReference[oaicite:13]{index=13}.
• Begin cooling by hosing with cool—not icy—water over large vessels (neck, chest, inner thighs); apply ice packs to head, neck, but avoid cooling hindquarters to prevent circulatory shock :contentReference[oaicite:14]{index=14}.
• Use fans or breezes to promote evaporative cooling :contentReference[oaicite:15]{index=15}.
• Scrape excess water; do not towel dry :contentReference[oaicite:16]{index=16}.
• Encourage small sips of cool water with electrolytes once stabilized :contentReference[oaicite:17]{index=17}.
• Monitor rectal temperature every 5–10 minutes; aim for gradual reduction to ~38–39 °C (100–102 °F). Stop cooling when in this range :contentReference[oaicite:18]{index=18}.
• Call your vet immediately—don’t wait :contentReference[oaicite:19]{index=19}.

5. 🚑 Veterinary Treatment Protocols

Vet management includes:

• IV fluids & electrolytes: To restore hydration and correct imbalances; large volumes often needed :contentReference[oaicite:20]{index=20}.
• IV cooling: Ice water infusion may be used in severe cases :contentReference[oaicite:21]{index=21}.
• Anti-inflammatories: NSAIDs like flunixin or ketoprofen to protect against shock and pain :contentReference[oaicite:22]{index=22}.
• Sedatives: Detomidine or xylazine for agitation or seizures, keeping horse calm but standing :contentReference[oaicite:23]{index=23}.
• Steroids: IV glucocorticoids if neurologic signs or DIC suspected :contentReference[oaicite:24]{index=24}.
• Supportive care: Monitor kidney/liver function, treat secondary complications (colic, laminitis, respiratory edema) :contentReference[oaicite:25]{index=25}.
• Hospitalization: Often required 24–72 hrs, with monitoring of vitals and bloodwork :contentReference[oaicite:26]{index=26}.

6. 🛡️ Prognosis & Recovery

Horses with mild heat stress typically recover fully. Heat stroke prognosis depends on:

• Speed of cooling and vet treatment.
• Presence/absence of CNS signs (better prognosis if none) :contentReference[oaicite:27]{index=27}.
• Development of complications like organ failure or laminitis :contentReference[oaicite:28]{index=28}.

Most recover with prompt care; poor prognosis if prolonged collapse, seizures, DIC, or severe organ dysfunction occur :contentReference[oaicite:29]{index=29}.

7. 🛡️ Prevention Strategies

• Acclimatization: Gradually increase exercise in warmer weather over 10–21 days :contentReference[oaicite:30]{index=30}.
• Avoid peak heat: Exercise early mornings or evenings when heat index <130–150 :contentReference[oaicite:31]{index=31}.
• Clip coat: Use light body clipping and ensure shade/ventilation :contentReference[oaicite:32]{index=32}.
• Water + electrolytes: Always available, especially during transport :contentReference[oaicite:33]{index=33}.
• Track weather: Avoid exertion in high heat/humidity conditions (heat index >150, humidity >75%) :contentReference[oaicite:34]{index=34}.
• Monitor at-risk horses: Foals, seniors, obese, poorly conditioned horses & those with anhidrosis particularly susceptible :contentReference[oaicite:35]{index=35}.
• Transport safety: Ventilate trailers, avoid midday travel, provide water & rest stops :contentReference[oaicite:36]{index=36}.

8. 🤝 Ask A Vet Emergency Support

With Ask A Vet, access remote guidance when dealing with heat emergencies:

• 📋 Heat-stroke response protocol: cooling steps, water/electrolyte dosing.
• 📆 Emergency follow-up plans: vitals/progress tracking, step-down care.
• 📸 Video reviews of vitals, gait, hydration.
• 🎓 Webinars: “Summer Riding Safety,” “Heat Acclimation Plans,” “Transport Heat‑Stress Guidelines.”
• 🔁 Preventative guidance: acclimation scheduling, condition planning, hydration strategies.

9. ❓ FAQs

Is ice ok for cooling?

No—avoid ice-water on body; scrub cool water continuously, ice packs on head/neck acceptable :contentReference[oaicite:37]{index=37}.

When should vet start treatment?

Call vet immediately—don’t await worsening signs. Rapid cooling + fluids before arrival improves outcomes :contentReference[oaicite:38]{index=38}.

How long to restrict exercise after recovery?

Most rest 3–5 days minimum; return to work gradually under vet guidance :contentReference[oaicite:39]{index=39}.

Can heat stroke recur?

Yes—previously affected horses are more vulnerable. Monitor carefully in hot/humid weather :contentReference[oaicite:40]{index=40}.

10. ✅ Final Takeaway

Heat stroke is a critical emergency, but swift cooling, veterinary treatment and diligent prevention save lives. With **Ask A Vet’s** remote assistance—cooling guidance, hydration planning, acclimation protocols—you can protect your horse through hot summer months of 2025 and beyond. As Dr Duncan Houston, I’m here to support you with expertise and care when every second counts. 🐴💙