The nation’s largest dog welfare charity is warning dog owners that ‘20 is plenty’ when it comes to exercising dogs this summer.

Dogs Trust says taking dogs out in temperatures as mild as 21C can be problematic for dogs, particularly brachycephalic, or ‘flat-faced’, breeds such as English Bulldogs, Pugs and French Bulldogs.

In fact, according to recent research from the Royal Veterinary College (RVC) in collaboration with Nottingham Trent University, English Bulldogs are 14 times more likely to suffer heat-related illness compared to Labrador Retrievers.

Over a third of owners of flat-faced dogs reported that heat regulation is a problem for their pet.

Most dog lovers will be aware that extreme weather and heatwaves can be dangerous – sometimes even deadly – for dogs, but many will be unaware that exercising dogs in early summer temperatures as low as 21C can cause heatstroke in dogs. In some cases, heatstroke can prove fatal.

The symptoms of heatstroke can include panting heavily, drooling excessively, appearing lethargic, drowsy or uncoordinated, vomiting, diarrhoea and collapsing.

Paula Boyden, veterinary director of Dogs Trust, said: “It’s great to see the sun shining – it feels like summer has finally arrived.

“But while this weather might be great for us, hot weather can cause problems for our canine friends.

“Most of us know not to walk or exercise dogs in extreme weathers, but even temperatures as mild as 21 degrees can cause problems, especially for those dogs with flat faces or underlying health conditions.

“There are so many things we can do to make sure our dogs stay happy and healthy in hot weather, but it is crucial we keep a close eye on them, even if we are playing indoors.

“That way, hopefully, we and our dogs will be able to enjoy a long hot summer.”

Dogs Trust advice to support dog owners this summer includes to avoid walking at the hottest times of the day, to take plenty of water with you when out with your dog and to avoid taking your dog out in the car on a hot day, even if travelling a short distance

To find out more about how to keep your dog safe this summer, visit www.dogstrust.org.uk/summer-weather