Five summer health risks that catch dog owners off guard

Summer is the best time of year to spend with a dog. It is also when some of the most serious and most preventable health incidents happen.

Heatstroke

Heatstroke kills dogs. A peer-reviewed study of UK emergency veterinary records from the 2022 heatwave found that one in four dogs treated for heatstroke died. The most common trigger is not being left in a car. It is exercise: over half of heatstroke cases in that study were caused by owners walking or running their dogs in hot conditions. (Source: Beard et al. 2024, Veterinary Record)

The practical thresholds: above 20 degrees C, shorten the walk. Above 25 degrees C, walk only before 9am or after 6pm. In a heatwave, skip outdoor exercise altogether during the middle of the day.

Signs of heatstroke: heavy laboured panting; excessive drooling; red or pale gums; staggering or collapsing; vomiting; confusion. Move your dog to a cool shaded area. Apply cool (not cold, not iced) water to their body, especially the neck, armpits, and groin. Fan them to help evaporation. Call your vet before you arrive so they are ready for you.

Flat-faced breeds: a lower safety margin

French Bulldogs, Bulldogs, Pugs, Shih Tzus, Boxers, and other brachycephalic breeds are at significantly higher risk of heatstroke than other dogs. Their shortened airways reduce how efficiently they can pant. For brachycephalic dogs, many veterinary guidelines suggest reducing exercise in temperatures above 18 degrees C. Do not be reassured by a Frenchie that seems to be coping.

Blue-green algae and water safety

Blue-green algae is cyanobacteria, and some species produce toxins that can kill a dog within hours of exposure. It appears as a greenish-blue scum or paint-like streaks on the surface of slow-moving or stagnant water. It is most common in warm, still conditions from June through September. If your dog has been in contact with suspected algae water, rinse them immediately with clean fresh water, prevent licking, and go straight to a vet. UK bloom alerts are published at environment.data.gov.uk.

Grass seeds

Grass seeds peak between June and August. The barbed seeds attach to fur, pierce the skin, and migrate inward. They cannot travel backward, only deeper. After every walk through long grass, inspect: between every toe on all four paws; around and inside the ear flaps; around both eyes; around the nose and lips. Signs a seed has already entered: obsessive licking of one paw; repeated head shaking; persistent sneezing; a weeping or closed eye. See your vet the same day. (Source: PDSA)

Hot ground and paw burns

On a 25 degree C air temperature day, dark tarmac in direct sun can exceed 50 degrees C. The standard test: place the back of your hand flat on the surface and hold it for seven seconds. If you cannot, it is too hot for your dog to walk on.

Sunburn and sun protection

Dogs can burn. Light-coated, short-haired, and pale-skinned dogs are most at risk: Boxers, Dalmatians, Whippets, Bull Terriers, and Staffordshire Bull Terriers. The areas most likely to burn are the ear tips, nose, eyelids, and belly. Repeated sunburn increases the risk of squamous cell carcinoma over time. (Source: PDSA)

Never use human sunscreen on a dog. Many human formulas contain zinc oxide, which is toxic to dogs and damages red blood cells. Use a pet-specific product with SPF 15 or higher. Apply to ear tips, nose bridge, and any area where skin is exposed. Reapply every two hours in direct sun.

The honest caveat: sun protection for dogs is underprescribed by owners and undersold in guidance. If your dog has pink or exposed skin and spends time outdoors in summer, they need it.

Frequently asked questions

Can dogs get heatstroke in a parked car? Yes. On a 22 degree C day, a parked car interior can exceed 47 degrees C within an hour. Cracking windows makes very little difference.

What temperature is too hot to walk my dog? Above 20 degrees C, shorten the walk; above 25 degrees C, walk only before 9am or after 6pm. Apply those thresholds around 2 degrees lower for brachycephalic breeds.

Can dogs drink seawater? No. Saltwater causes vomiting and accelerates dehydration. If your dog drinks seawater, offer fresh water as soon as possible.