Heatstroke & Hyperthermia in Dogs and Cats: Symptoms, Diagnosis & Treatment [2025]
Heatstroke is a life-threatening emergency — a body temperature above 40°C requires immediate cooling. High-risk groups include brachycephalic breeds and overweight pets; delayed treatment can lead to multiple organ failure.
When to See a Vet
Seek Emergency Care Immediately
- •Completely unable to stand and unresponsive
- •Persistent severe panting or difficulty breathing
- •Seizures or uncontrollable full-body trembling
Schedule a Clinic Visit Soon (within 24–72 hours)
- •Abnormal lethargy or difficult to rouse but still responsive
- •Repeated vomiting or persistent diarrhea over multiple episodes
- •Noticeably reduced water intake and unwilling to drink
01What symptoms indicate something is wrong?
During heatstroke or hyperthermia, dogs and cats commonly display a range of abnormal behaviours and physiological signs that owners can observe. Early detection helps ensure prompt veterinary care.
- Rapid heart rate or noticeably increased pulse
- Rapid breathing or open-mouth panting (particularly in cats)
- Unsteady gait, sluggish movement, or weakness
- Persistent trembling or involuntary muscle twitching
- Confusion, lethargy, or reduced responsiveness
- Vomiting, drooling, or inability to eat or drink normally
Seek emergency care immediately if you notice the following symptoms:
- ⚠️ Sudden hind limb weakness or complete inability to move
- ⚠️ Unconsciousness or loss of consciousness with no obvious response
- ⚠️ Rapid breathing or signs of significant respiratory distress
Pet Health Map App
Turn every worry into your pet’s health record
Download the app to save AI Care reports, build your pet’s medical profile, and keep tracking symptoms and care notes.
Android version coming soon. The web version is available now.
02How to assess the situation at home: observation tips and when to seek emergency care
Observing and documenting your pet's condition at home helps the vet assess the situation quickly on arrival — always note the timing and progression of changes.
- Note the time symptoms began, frequency of trembling, and how long each episode lasts
- Observe mental status: alert, lethargic, or unresponsive
- Record food and water intake over the past 24 hours
- Note the frequency of urination and defecation, and any changes in colour or consistency
- Weigh your pet and note any weight changes over the past two weeks (if applicable)
- If symptoms worsen, arrange a vet visit or emergency consultation immediately
03How will the vet make a diagnosis? Common diagnostic tests
Once at the clinic, the vet will prioritise vital signs and use blood tests, imaging, and urinalysis to assess dehydration, organ damage, and complications.
Complete blood count (CBC)
to check for infection, bleeding, or anaemia
Blood biochemistry
to assess liver and kidney function and electrolyte imbalances
Urinalysis
to confirm dehydration and evaluate kidney stress
Chest and abdominal X-rays
to assess organ appearance and detect complications
Ultrasound (abdominal or cardiac)
to evaluate organ damage when necessary
Advanced imaging (CT or MRI)
for further evaluation of complex complications
Choose a clinic that can provide emergency IV fluid therapy and oxygen support
04Treatment and aftercare: medications, dietary adjustments, and home care guidance
Heatstroke treatment focuses on stabilising vital signs and preventing organ damage; follow-up monitoring of temperature, blood values, and clinical signs is essential after discharge.
- Intravenous fluids to rehydrate and correct electrolyte imbalances
- Supplemental oxygen as needed to address hypoxia
- Medications prescribed by the vet to manage complications or inflammation
- Continuous monitoring of temperature, heart rate, and respiratory rate
- Schedule follow-up visits for blood tests or imaging to monitor recovery
- Severe cases may require specialist referral or hospitalisation for observation
05What to prepare before the vet visit: key information to help the vet assess quickly
This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.
