How to Keep Your Sighthound Cool in Summer

If your Greyhound, Whippet or Italian Greyhound spent a hot summer day asleep on the coolest spot in the house, they're probably doing it right.

Keeping a sighthound cool in summer is usually less about cooling products and more about preventing overheating in the first place. The most effective approach is to avoid strenuous activity during hot weather, walk during cooler parts of the day (ideally below 26°C), provide constant access to shade and water, and allow your dog to rest, seek cool surfaces and recover after activity.

Research suggests that most heat-related illness in dogs is linked to exercise rather than hot cars, despite popular belief.

One of the most useful things we've learned from living with sighthounds is that they rarely waste energy when they don't need to. On hot days, many naturally seek shade, cool surfaces and rest long before we think they should. Science helps explain why. The challenge isn't usually cooling a dog down. It's recognising when they're already trying to do it themselves.

How do sighthounds regulate their body temperature differently from other dogs?

Spend five minutes with a sighthound in summer and you'll quickly discover they're not interested in impressing anyone. While other dogs are still chasing balls, yours has already relocated to the only patch of shade in the garden and is considering whether moving again is really necessary.

There may be a good reason for that. Research suggests that sighthounds experience temperature differently from many other breeds. Studies in Greyhounds show they are exceptionally lean, generate heat rapidly during exercise, and may have a lower thermoneutral zone than some non-sighthound dogs. In practical terms, they appear to have less thermal buffer at both ends of the spectrum, becoming cold more quickly in winter and gaining heat surprisingly fast during activity.

Greyhounds have been reported to have a thermoneutral zone of approximately 16-24°C, meaning a temperature range in which the body does the least work to either warm up or cool down. While no equivalent research exists for Whippets or Italian Greyhounds, their smaller body size and lower thermal mass may mean their thermoneutral range is narrower, although this has not yet been formally studied.

Source: Effect of breed on body composition and comparison between various methods to estimate body composition in dogs

Why do sighthounds overheat so quickly during exercise?

One of the biggest mistakes owners make is assuming that once the running stops, the recovery starts. Unfortunately, that's not always how it works.

Sighthounds were born to accelerate from zero to extraordinary speeds in a matter of seconds. That explosive athleticism comes at a cost: heat. Studies on racing Greyhounds found body temperature increased by an average of 2.1°C after a race, with some dogs exceeding 41.5°C in warmer conditions. More surprisingly, body temperature remained elevated after exercise had ended.

In other words, a dog that looks recovered may not actually be recovered.

Anyone who lives with a sighthound has probably seen this play out. Ten minutes ago they were tearing around the park at full speed. Now they're stretched across the grass, panting heavily and refusing to move. It can look dramatic, but the research suggests they're doing exactly what their body needs them to do: stop generating heat and start getting rid of it.

What causes heatstroke in sighthounds?

Ask most dog owners what causes heatstroke and they'll probably say the same thing: a dog walked in the midday sun or a dog left in a hot car.

They're not wrong. Hot cars are dangerous. They're just not the most common cause.

A study of more than 900,000 UK dogs found that almost three quarters of heat-related illness cases were linked to exercise. Vehicle confinement accounted for just 5.2% of cases. In fact, among exercise-related cases where the activity was known, walking was the single most common trigger.

The researchers concluded:

"In the UK, exertional heat-related illness affects more dogs, and kills more dogs, than confinement in a hot vehicle."

The reason is surprisingly simple. Dogs generate heat when they move. Running generates heat. Playing generates heat. Chasing a ball generates heat. Even excitement generates heat. Heatstroke occurs when the body produces more heat than it can get rid of.

Among exercise-related cases where the activity was known:

• 67.5% occurred after walking

• 17.6% occurred after running or cycling

• 13.8% occurred during play

For sighthounds, this is particularly important to understand. They are built for explosive bursts of speed and can generate large amounts of heat very quickly. A cool morning walk, a game of chase with another dog, or a few minutes of zoomies can all produce more heat than many owners realise.

The weather matters. But what your dog is doing often matters just as much.

How do dogs actually cool themselves?

Unlike humans, dogs have very few sweat glands and cannot cool themselves efficiently through their skin. Instead, they rely on evaporation from the tongue, mouth, nasal passages and respiratory tract. Every breath helps move heat away from the body.

This is one reason hot, humid weather can feel particularly difficult for dogs. Panting works best when moisture can evaporate easily. When the air is already warm and damp, that cooling system becomes less effective.

It also explains why many dogs instinctively seek shade, cool surfaces and airflow during hot weather. They're not just trying to cool their skin. They're creating conditions that make their body's natural cooling system work more efficiently.

Are cooling vests good for cooling a sighthound?

Cooling vests are often marketed as a way to prevent overheating, but the reality is a little more nuanced.

Some cooling products may improve comfort in warm weather, but Greyhound-specific research has raised questions about whether garments that cover key heat-exchange areas could actually interfere with cooling. Dogs primarily lose heat through panting and through specialised "thermal windows" such as the head, chest, groin and paws.

Regardless of the product being used, the same principles still apply: reduce heat generation, provide shade and water, and allow adequate recovery after exercise.  In other words, cooling vests may help support a dog's natural cooling system, but they are not a substitute for sensible heat management.

One of the easiest mistakes to make is assuming a dog wearing a cooling vest can stay active for longer. In reality, the same rules still apply. If your sighthound is seeking shade, slowing down, lying on cool grass or refusing another lap of the park, they're already telling you something important.

A cooling vest may help them stay comfortable. It doesn't mean they're no longer hot.

Practical ways to keep your Greyhound, Whippet or Italian Greyhound comfortable in summer

Common myths about sighthounds in summer

Heatstroke mostly happens in hot cars

Reality: Exercise is a much more common trigger.

A dog that has stopped running has cooled down

Reality: Body temperature remains elevated after exercise.

Thin-coated dogs cannot overheat

Reality: Greyhound studies show athletic sighthounds can gain heat rapidly during activity.

Cooling vests prevent heatstroke

Reality: They may help reduce heat load but cannot replace sensible heat management.