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Can You Leave Your Dog In Car With The AC Running?

You just need to pop into the store, and it seems like such a faff to get the dog out, put his lead on, and take him with you. Especially in warmer weather, it may seem like a good idea to leave your dog in the cool car with the ac running. But is this acceptable? Will it cause them any harm? Well, here is everything you are going to want to know and consider. 

So, can you leave your dog in the car with the ac running? Veterinarians advise against leaving your dog in a car with the AC running for any longer than 5 minutes. This is because there is always the risk of an ac malfunction, which could result in your dog quickly overheating. Leaving the engine running can also lead to other risks, such as your dog accidentally knocking the gear lever.

While I certainly get where you’re coming from, in reality, it’s not really a good idea.

But what can you do instead?

We will get into that shortly.

But first, this poses the question; is the AC dangerous to dogs altogether?

Let’s turn to that next, shall we? 

Is AC Harmful To Dogs? 

Air conditioning (AC) is not harmful to dogs at all. Many dogs love the feel of a cool breeze on their face, especially in hot weather. In fact, it’s recommended that you run the aircon for a few minutes before setting off on a journey with your dog to reduce the risk of heatstroke. 

Dogs have a higher body temperature than humans, so they can overheat very quickly, even in cooler weather. 

It’s also worth bearing in mind that certain dog breeds are more susceptible to heat stroke than others. 

For example, brachycephalic dogs (short-nosed breeds), such as Bulldogs, Boxers, Pugs, and Shih Tzus, are at higher risk of developing heatstroke because they already struggle to breathe somewhat, even when at rest. 

Dogs don’t sweat like humans. In fact, they are only able to sweat via sweat glands called merocrine glands located on their paw pads.

Their main system of cooling is through panting, which is less effective in flat-nosed (brachycephalic) dogs. 

Double-coated or long-haired dog breeds such as German Shepherds, Huskies, and Chow Chows are also at higher risk.

These dogs were specifically bred to withstand extremely cold temperatures, so their coats are not good at letting heat escape.

In addition, overweight or obese dogs struggle more in higher temperatures because their bodies have to work harder to keep them cool.  

Signs of heatstroke to look out for include: 

  • Rapid breathing 
  • Lethargy 
  • Dry gums 
  • Excessive drooling 
  • Reddened or very pale gums 
  • Vomiting 

If you notice any of these signs in your dog, it’s essential that you cool them down. 

You can do this by moving them to a shady spot, gently running cool (not cold) water over them, or by letting them sip cold water. 

You should also seek advice from your vet because severe heatstroke can be fatal. 

Can AC Make Your Dog Sick? 

There is no evidence to suggest that AC can make your dog ill or sick. However, you do need to be careful of the temperature. If it’s too cold, then it could lead to hypothermia but generally only if it’s been left on for long periods of time. 

Young puppies are particularly susceptible to the cold as they can’t regulate their temperature as well as adults. 

Dog breeds that have been bred to withstand hot temperatures, such as Chihuahuas, Beagles, Great Danes, Greyhounds, and even Poodles, have short, thin coats that also struggle with cold temperatures. 

You need to be especially careful about the temperature of the aircon if your dog has been jumping in puddles or diving into the sea because wet skin can cause them to cool down even more quickly.  

Symptoms to watch out for include: 

  • Shaking or shivering 
  • Excessive whining or vocalizations 
  • Seeking shelter 
  • Cold ears 
  • Curling up 

Remember that the body temperature of dogs is around 3°F higher than ours, so always take this into account when deciding on the best temperature for your air conditioning. 

Older dogs also have a weaker immune system than younger dogs which can make them more susceptible to extreme temperature changes in the environment, as well as dogs with underlying health conditions.  

In addition to temperature, aircon can pose other risks if it’s left on too long. 

Air conditioning systems act as dehumidifiers by condensing water droplets out of the air. 

This can cause the air inside the car to become dry. For most dogs, this isn’t too much of a problem, although you should ensure your pup has access to water at all times. 

However, dogs with skin conditions or those with medical issues such as bronchitis may struggle with the dry air.

Always keep an eye on your dog and never leave them alone in a car for longer than a few minutes, even with the air conditioning on.  

What AC Temperature Is Good For Dogs? 

Unfortunately, there are no set guidelines on the optimum air con temperature for dogs because it depends on a variety of factors, including your dog’s breed, age, and health status. However, in general terms, most dogs will struggle with anything under 40°F. On the other end of the scale, temperatures over 78°F will be uncomfortable for most dogs. 

Remember that cars are enclosed spaces, so if it’s 70°F outside, it can easily reach 103°F on the inside within 20 minutes. 

At this temperature, most dogs will struggle with heat exhaustion which is a precursor for heat stroke. 

The optimal environmental temperature for dogs is 69-75°F, whether that’s in a home, outside, or in the car.  

Yes, air conditioning is a great way to reduce the overall temperature in the car to some degree, but it’s not fool-proof, and often the temperature gauge is misleading.  

How Long Can You Leave A Dog In A Car With The AC Running? 

Veterinarians recommend that you only leave a dog in the car with the AC running for up to 5 minutes and only if this is completely unavoidable. 

Popping out to run a quick errand can easily turn into a longer venture if you get stuck in queues, bump into a friend, or simply lose track of time.

This can cause serious health issues for your pet which is why the Humane Society advises that it’s generally unsafe to leave a dog in a car for any length of time, regardless of the outside temperature.

Even cold outside temperatures can turn your car into a refrigerator very quickly.  

Leaving a dog alone poses a number of risks, including attempted break-ins (especially if the car isn’t locked), engine failure, air-con malfunction, and the risk of your dog escaping.

If your dog is left loose in the car, they may also accidentally nudge the gear stick or the handbrake, which can lead to even bigger fatalities.

If they accidentally turn the air conditioning off, the cool air will immediately turn to hot air, which will cause the temperature to rise dramatically in a very short space of time.  

Many people believe that leaving the window cracked open a little bit can help to keep the car cool in hot weather.

However, this isn’t true.

According to the American Veterinary Medical Association (AVMA), cracking the window makes absolutely no difference to the temperature increase inside the car in warm weather.

If the outside temperature is 75°F, the temperature inside the car can reach 94°F within 10 minutes!

Within 30 minutes, the temperature can reach an eye-watering 109°F. So, it’s always best to leave your dog at home or in the care of someone else when you are out running errands.

Also, remember that leaving a dog alone in a car is illegal in some states, and all 50 states have animal protection laws that are designed to protect the welfare of our pets.

By leaving your dog in a car alone, even with the air con on, you could be endangering their life. 

It’s not just the external temperature that can put them at risk. A dog’s body temperature can also rise due to stress.

Furthermore, a dog continuously panting can raise the temperature level in the car even further.  

Best Practices To Keep Your Dog Cool In The Car

Sometimes, leaving your dog in the car for a few minutes is simply unavoidable, or its a hot day and you need to travel.

So here are a few tips to help you keep them cool: 

Don’t Leave Them For Too Long

As mentioned above, dogs should not be left alone in a car for more than a couple of minutes.

Always have your dog’s welfare in mind and avoid getting side-tracked.  

Invest In A Cooling Pad?

Cooling mats are a great way to keep dogs cool in hot weather.

These innovative products contain a solid gel and specific chemicals that are designed to absorb a dog’s heat and therefore cool them down.  

Leave Your Dog With A Passenger

If you can, leave a friend or relative in the car with your dog while you are out running errands.

They will be able to keep an eye on your dog and take action if the temperature gets too unbearable in the car.  

Use Sunshades 

Adding sunshades to your windows will help to keep the car a little cooler, as will parking in a shady spot.

However, bear in mind that this method should not be used for more than a couple of minutes as the temperature can still rise dramatically. 

Have Your Car Serviced Regularly

There have been many instances of dogs dying in hot cars because the engine failed or the air-con system broke down.

Always make sure your car is in full working order and get any issues checked out as soon as possible.  

Travel With Cold Weather

Always make sure your dog has access to a bowl of cold water to help him regulate his body temperature.  

Purchase A Car Temperature Alert System 

You can now purchase safety systems that will alert you via text or an app when the inside temperature of your car is too high for your dog. 

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Remember that all these measures are short-term solutions only.


Can you leave your dog in the car with the AC running? Perhaps. But you shouldnt.

In fact, it could even be illegal depending on where you are or live.

And outside of just the law, it’s not considered particularly safe for your dog. Regardless of temperature (even though this can be a serious risk factor).

So ultimately, the best way to keep your dog safe is to leave them at home rather than in the car.  

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