The RSPCA has issued a warning to dog owners as the UK continues to experience a scorching heatwave, identifying nine key indicators of heatstroke that could help owners intervene before it becomes critical. Heatstroke can be fatal for dogs, yet many owners fail to spot early warning signs.
At-Risk Dogs and Immediate Actions
According to the animal welfare charity, while any dog can suffer from heatstroke, flat-faced breeds, elderly dogs and overweight pets are among those at heightened risk. The charity urges owners to take immediate action if they notice their dog becoming unwell in the heat. The warning arrives as temperatures remain elevated across much of the UK, with the Met Office issuing red heat alerts for certain areas. Forecasters caution that extended spells of hot weather can present dangers not only to people but also to animals that find it difficult to regulate their body temperature.
Nine Warning Signs of Heatstroke
Collapse
Collapse is among the most critical warning signs of heatstroke. The RSPCA states that a dog which collapses in hot weather requires immediate veterinary attention while owners begin cooling them with cool—not ice-cold—water.
Confusion or Disorientation
Dogs experiencing heatstroke may become confused, unsteady on their feet or seem disorientated. According to the RSPCA, dehydration can impact a dog's movement and behaviour as their body struggles to manage rising temperatures.
Dehydration
The RSPCA warns that dehydration can lead to a dry nose, sunken eyes, heavy panting, reduced urination and unusual lethargy. Ensuring fresh drinking water is consistently available is one of the most straightforward ways to keep dogs safe during periods of hot weather.
Drooling
Drooling that turns heavier, thicker or stickier than usual can also be a warning sign of heatstroke. The charity advises owners to take note if excessive drooling is accompanied by other indicators of overheating.
Increased Heart Rate
A dog's pulse may quicken as it becomes too hot. The RSPCA recommends checking their heartbeat by placing your hand on the chest just behind the front leg, though heart rates naturally vary between larger and smaller breeds.
Muscle Spasms
Muscle spasms, shivering or trembling can emerge as dehydration deteriorates. According to the RSPCA, these heat cramps are a further indication that a dog's body is struggling to control its temperature.
Noisy Breathing
Breathing that becomes unusually loud or considerably faster than normal should never be overlooked, particularly in flat-faced breeds. Research referenced by the Royal Veterinary College has revealed that brachycephalic dogs are significantly more prone to developing heatstroke, as they are unable to cool themselves as effectively through panting.
Panting
Panting is how dogs naturally regulate their temperature, but excessive or prolonged panting can signal they are becoming overheated. According to the British Veterinary Association, heatstroke can develop quickly, making it crucial not to dismiss persistent heavy panting in hot conditions.
Red Gums and Tongue
Bright red gums or a red tongue can be another warning sign when combined with heavy panting or difficult breathing. While this can occasionally be related to dental issues, the RSPCA says it should never be dismissed if a dog has been subjected to high temperatures.
What to Do If You Suspect Heatstroke
If you suspect your dog has heatstroke, the RSPCA recommends moving them into the shade straight away, providing fresh cool water if they are capable of drinking, and starting to cool them with cool—not ice-cold—water. Owners should then contact a vet immediately, as swift treatment gives dogs the greatest chance of recovery.



