As Canicrossers, the health and wellbeing of our dogs is our main priority. We love getting out there and running whenever we can, whatever the weather. However, when the weather warms up, how hot is too hot?
This is a question we are often asked, especially by people who are new to the sport. Our guests in this interview are canine researcher, Anne Carter, and small animal vet, Emily Hall from Hotdogs. They have a website where they share their research into canine heatstroke and other heat-related disorders.
Welcome to you both. First of all, to give everyone a bit of background, could you tell us a bit about yourselves and why you are so passionate about what you do?
ANNE: I am a senior lecturer at Nottingham Trent University. I have been there for just over ten years now. I have been Canicrossing for about 13 years and life drawing for about five. My research interests and my personal interests combined when I started to question whether we should be running our dogs in hotter weather and whether there’s a risk to them in doing so. I met Emily when she joined Nottingham Trent University and pulled her into the heatstroke research we were starting to do.
EMILY: I am a small animal vet and have worked in practice for about a decade. I then moved into teaching. As Anne said, I was looking for a research project to dip my toe into. I’m afraid I’m a cat owner, but every job I have ever had has been conducive to owning a dog! I have lived vicariously through other people’s dogs, including my parents’ golden retriever, which suffered from mild heat-related illness, that I might talk about later.
What are the signs that we need to look out for when we are out running our dogs and the temperatures are rising? We’re in April now and having the odd cooler day and then plenty of warmer ones.
EMILY: Now is the time be looking at temperatures. We’ve had a relatively cold winter and the dogs haven’t been out in the heat for a while. So, they’re not currently acclimatised to it. We are coming into the danger zone, where if we have sudden hot spells, they’re going to hit harder than they would in the middle of summer. What we would really like people to recognise are the very early warning signs that a dog is starting to struggle with the heat.
These can be very simple things, such as excessively panting. Hopefully, if you run with your dog, you know what they look like when they get a bit tired. Excessive panting is different to that. It’s like they can’t stop. Their tongue is all the way out of their mouth, really extended and flattened. Their mouth will be gaping and their chest will be going like bellows. We have a video of a dog doing this so you can see what it looks like. It’s much easier to see it than for me to describe it.
If your dog is having difficulty breathing, that can also be a sign. As things progress, they can struggle to continue with exercise – or be unwilling to carry on. They might start laying down, becoming quite tired. Subtle changes for sports dogs include a lack of focus and lack of performance. One of our research participants – a vet and avid Canicrosser – told us about an incident that happened with her dog last year when he overheated. She noticed because he wasn’t tracking straight or pulling the way he normally did. When she really looked at his breathing, she realised what was happening and that they needed to stop.
If you don’t spot these early signs, things will potentially progress and then you are looking at vomiting, diarrhea and hypersalivating. If your dog has ever been car sick and you wondered how they could have produced so much saliva that it soaks through the seats, that’s hypersalivation. If things then progress beyond that, you are looking at seizures, neurological deficits, blood in the vomit or diarrhea, losing consciousness completely – they will stop panting at that point – and death.
There are clearly a number of stages involved and we don’t want to get to the more extreme ones for sure, but even the very early ones are to be avoided as much as possible. Just like people, dogs are all different. Are there any breeds that tend to be more susceptible to warmer weather? Is the breed a significant factor?
ANNE: There are certain breeds that are more at risk than others. Certainly, the brachycephalic, or flat-faced breeds struggle more to regulate heat and keep themselves cool. Dogs like French bulldogs, pugs, cavalier King Charles spaniels. There are also other breeds that are affected – perhaps the ones you wouldn’t expect quite so much to be at higher risk – like springer spaniels, golden retrievers or greyhounds. There’s quite a mix there, but at the same time, that’s not to say other breeds are not also at risk alongside them. You can’t just say, oh that’s OK as I have a German short-haired pointer, for example. The risk is still there for any dog.
EMILY: Yes, any dog can be affected; that’s the message we want everyone to remember. However, if you have one of those breeds that are more at risk, it’s even more important that you remember how to spot the signs that they may be overheating.
ANNE: Even within the same breed you can have one dog that copes better with the heat than another. I used to have two staffies and one was much better at being in the heat than the other. He felt it a lot more so we had to be more cautious going outside with him.
EMILY: Looking at the Canicrossing side of things, there could be an assumption that if the dogs still wants to pull, it still wants to run, so it must be OK. Some breeds have such a high drive and desire to run that it can be much harder for an owner to know when it is time to stop and pull them up for a rest when they are getting too hot. If the owner doesn’t stop, such a dog will continue until the end of the race or training run and end up overdoing things. That’s why dogs like springers may be more susceptible to overheating too, because they are so high-energy and on the go the whole time.
That’s a really interesting point; some dogs will happily go on forever and we can’t expect them to tell us when they have had enough. One of the things you said earlier, Emily, is that the critical time is when there are sudden changes in temperature. You wrote a blog post about keeping your dog active over the winter months, which can help you transition into warmer temperatures. Could you tell us a bit more about that?
EMILY: It’s the same with us humans. If you get to the summer and you have been physically fit and athletically training, have maintained a healthy body weight and are feeling healthy overall, you will feel more able to cope with the heat. Heat can be dangerous to everyone, regardless of how healthy you are, but if you are fit, you will tend to cope with it a lot better.
So, letting your dog slack off a bit during the winter because it is a bit cold and rainy will not help them, especially if they are carrying a few extra pounds or excess fat. The fat will trap the heat in their body, making it harder for them to cool down. If they become really obese, then the extra fat will take up space in their body where they should be breathing, so that will really limit the effects of their panting and stopping them from cooling down quite so much.
We also know from human, equine and canine science that the act of cooling your body down requires quite a significant increase in how hard your heart has to work to pump blood around your body to get it to the surface to cool down. So, if your heart is fit going into the summer, it will cope better with the extra stress and will be more effective at cooling down the body. Keeping your dog fit over the winter is therefore important for all sorts of reasons.
Our next question is, bearing all of that in mind, can you really run your dog safely in the summer?
EMILY: There is always a risk at any time of year. We’ve seen records of dogs who have died from heatstroke in January when there has been snow on the ground. As ambient temperatures rise, however, that risk does increase. There will be some dogs that can generally run well in hot weather, but can you, hand on heart, predict which dogs these will be and how high the temperature or pace needs to get before it stops being safe for them? In Canicross, they are pulling alongside a human, which adds even more physical stress to their situation.
It’s a case of doing a full risk assessment before heading out and deciding whether or not you could respond quickly enough, should the worst happen and your dog starts to overheat. How far are you away from transport to go and get help? Is there water nearby that you could use to cool them down? Can you recognise the signs that your dog is starting to struggle and could you pull over to help them straight away?
Do you have the self-control to stop when it is best for your dog, rather than carry on for longer to meet your own goals? We know that doing races can make us feel hotheaded and determined to ‘push through’, but is it worth it if your companion is not going to make it?
ANNE: We always say that the dog must come first, 100% of the time. If in doubt, you don’t take your dog out. It’s a difficult one, though. You can’t say never run in summer. Our summers in the UK can vary so much in temperature and weather conditions. Also, where you run can affect what you do. If you run a lot in the shade, for example, or go out really early in the morning, this can help keep your dog much cooler. Be guided by what you feel is safest for your dog. If you are running in a bigger group and everyone else has said that it’s OK for their dogs to run that day, is it OK for yours to join them?
I run with my dogs throughout the summer, but at ‘stupid o’clock’ in the morning to make sure that it is nice and cool. We don’t necessarily go out every day in summer either. If there are days that they have to miss out on because it is just too hot, it’s not the end of the world. If they go out and it’s too hot for them though, it could kill them. It’s about making the right decision and sticking by it.
Emily, you said earlier that a dog with increased weight that didn’t stay fit during the winter would be at increased risk in the heat. Is there anything else that could add to the risk?
EMILY: Anything that could impact on their ability to cool down. Whereas humans and horses sweat to cool down, dogs don’t. They do have sweat glands and produce sweat, but that’s not sweating to cool down. They cool down by panting. Panting uses as much liquid as sweating does, so they need to be well hydrated. If they are not properly hydrated, they will not cool down as effectively.
Whenever you are worried that your dog might not be properly hydrated, you must be super careful with them. This could be after they have had diarrhea or vomiting, or if they haven’t eaten or drunk as much as they usually would at their last meal. Or, you could have been travelling a long distance by road and they haven’t had as much access to water as you know they would normally have done at home.
Panting is really important for dogs – anything that impacts badly upon their ability to breathe freely and pant should be avoided. If you dog has a bout of kennel cough, for example, you could be looking at months before their respiratory tract is completely healed. As vets, we see dogs present with heatstroke after having kennel cough as they just can’t breathe. Anyone who has had Covid will understand how that feels!
As Anne has already said, flat-faced dogs are at increased risk from BOAS (Brachycephalic Obstructive Airway Syndrome). Overheating is one of the symptoms that we use as vets to decide whether surgery to correct this. Another risk is laryngeal paralysis, which is particularly common in big breed like Labradors, retrievers and greyhounds. That’s where the vocal cords in the larynx stop opening, so it’s like trying to breathe through a squashed paper straw. You usually know when your dog has that because it makes a roaring noise when it breathes, but that’s not always the case. In the case of my parents’ dog, we didn’t know she had laryngeal paralysis at first because she was completely silent. We only noticed when she started collapsing and overheating on walks. Any large dogs from middle to old age can be at risk of that.
Do dogs develop a bigger risk for this as they get older?
EMILY: Yes, they do. It’s one of those things where we’re not entirely sure why it happens, but it does. It could be to do with the route the nerves take in the neck, but it is something to watch out for as you dog gets older, especially in some of the bigger breeds. Likewise, anything that you do to a dog’s throat that could constrict its breathing while running adds to the risk, such as people running their dogs with a collar – seeing that always makes me feel incredibly anxious. We know from Anne’s research that this compresses the airway and narrows the space they have got to breathe through.
The heavier the dog, regardless of its breed and whether the weight is from the breed type or obesity, the hotter it will get when being active – and the longer it will stay hot compared to smaller dogs, purely from a thermodynamic point of view. Thick coats can be a problem too. Really thick coats can trap heat against the skin and stop the dog from cooling quite so effectively. Finally, from our research findings, any dog over the age of eight must be more careful in the heat.
There’s a lot of common sense involved, isn’t there? Things like not running with a tight collar on and using a proper harness instead so it is not restricting movement or blocking the airway at all. However, in the worst-case scenario when a dog might be showing signs of overheating, what measures should people take immediately?
EMILY: The first thing is recognising what’s happening – that’s so important. Knowing the signs, roughly how bad the situation is and how urgently you should take action. If you are out exercising, stop. That’s the first thing to do. Stop whatever activity is making them too hot and get them to lie down in the shade and calm down. If they are still panting and not responding after that, then look for some water.
Water is the most effective way we have for cooling dogs. That comes back to knowing your route and where there is water available – or carrying some yourself. People often worry about whether it should be tepid or lukewarm, but it just needs to be water! Tap water is perfect. Immerse them in it, or get them to drink it. It needs to reach their body quickly, so if you have a particularly fluffy dog, then part the fur to pour the water directly onto the skin. Phone your vet and get their advice. Find out where the nearest vet is and be prepared to travel there if necessary.
ANNE: While you are driving to the vet, turn the air conditioning on in your car to make sure it is nice and cool inside the vehicle. Once you have cooled the dog down enough to be able to move them safely, this helps them stay cool on the journey. You haven’t got them nice and cool with water only to put them into a hot car to heat back up again.
Should you try to get them to drink as well? Is it more important to cool their skin down or to get the water inside them?
EMILY: If your dog wants to drink, it’s not a problem. In fact, it’s a very good sign that they’re not feeling sick. However, if you think about the size of their stomach compared to the overall size of the dog, it will be far more effective covering the whole of their body surface area than just the smaller stomach part.
There are a lot of dog cooling coats out there on the market – even ones specifically designed for running. What are your thoughts on those?
EMILY: There’s no real evidence to say that these coats work. There is, however, evidence that they don’t work with horses – you know, the fabric ones that you load with water and then the fabric is supposed to hold the water. During tests, people put them on horses after exercise and the moisture holding breathable fabric performed no better than doing nothing at all.
Our approach to cooling jackets, wet towels etc. is that if it is a hot day, your dog is resting and looking uncomfortable and a jacket or towel appears to make it more comfortable while you are supervising them very closely, then that is OK. It’s like us when we pull on a wet t-shirt in summer and instantly feel a bit better. However, we do not recommend having them on the dog while they are exercising.
Anne and I have tried out some of these things and they start drying out within 15 minutes. As soon as they are dry, they are just normal jackets that actually hold in the heat and add an extra insulating layer. If you are leaving the dog unattended, they are going to dry out unnoticed and cause more harm than good. My preference would always be to give the dog a wet towel to lie on. They can move away if they don’t like it and also, for big, fluffy dogs, their legs, belly and thighs will be touching the wet surface directly, allowing the cooling water to reach their skin more easily. Using a flat towel also allows the heat to rise and dissipate more easily than a jacket that is wrapped around the dog.
ANNE: Ultimately, if you feel that you need to put a cooling coat onto your dog before it can safely go for a run, then the weather is probably too hot to go outside and exercise in the first place.
Going back to drinking water, people can drink too much water as well as not enough. Can that happen to dogs as well?
EMILY: Absolutely. Water toxicity can be a real issue in dogs. Some trainers refuse to use toys and treats when there is water involved. If a dog drinks a large quantity of pure water it can cause their brain to swell and can be fatal.
ANNE: In the summer, if a dog is swimming in the sea or a lake, or playing with a hosepipe and gulping in the water, you can get water toxicity associated with that as well.
What are your thoughts on charts; facts and figure that tell you whether it is too hot to run your dog or not? If your dog is quite fit and one of these charts tells you that it fine to go out for a run, should you believe it or is there more to it?
EMILY: I don’t think we will ever be able to say that there is a categorically safe temperature to exercise. A fat, brachycephalic dog with BOAS that can’t breathe and is a bit dehydrated could overheat in very cold conditions. They could overheat just sitting down in room-temperature conditions, frankly. There is no safe temperature.
Our rule of thumb is that if the ‘feels-like’ temperature, which takes into account the sun, humidity, air temperature and wind speed, is getting anywhere above 16 degrees C, then you need to do a serious risk assessment. Anything over 10 degrees C and you must have a back-up plan for if anything goes wrong while you are out.
What questions would you include in a risk assessment?
EMILY: How fit is my dog currently? Are we at the start of their training or have we been running for several months and they are now at peak fitness? How hot has it been recently? If it is August, for example, and July has seen a heatwave with temperatures in their 30s, then your dog is going to cope a lot better in the heat than they are trying to run in April during a suddenly warm Easter weekend. How well is the dog? Are they healthy or have they recently had bouts of vomiting, diarrhoea or not eating properly?
What am I planning to do with them and how much work will be involved? How long will it take? Do I have a means to respond if there is an emergency? For example, am I heading out somewhere with no shade or water, going up and down a lot of hills? Is it a long way back to the road and transport if I need to get to professional medical help? Can I carry my dog if necessary? If not, how will I get them out of danger if they were to collapse?
Good questions! Everyone likes to have a chart, a formula for things like this. Is it even worth looking over a rough guide to temperatures, or should you go by the examples you have given and bypass the charts completely?
ANNE: It’s much more valuable to work through these types of questions and to think about your own dog and your own circumstances than to look at any type of chart or table. The risk with charts is that they lull you into a false sense of security. You think, well it says that it’s OK to go out, so I’m alright. I’m sure you have gone outside some days and it has only been five degrees C, but it has felt really quite warm. Other days at the same temperature, you wish you had put long sleeves and gloves on!
It’s all of those other components as well that are so important. Is it sunny? Is it humid? If it’s windy, is it a cold or warm wind? We often use weather apps to compare with these charts because the apps will give you a real-time ‘feels-like’ temperature. However, it’s often not for the exact location where you will be running; it’s based on the nearest weather station instead. So, that’s another thing to factor in. If you look at a temperature from an actual thermometer in the actual place where you want to run, it could well read a fair bit higher than what’s on your weather app. I think knowing your dog and the circumstances in which they are safe to run is much more valuable.
Personally, I have arbitrary cut-offs for my dogs and they are different for each one. One of them can get very hot. He’s a pointer, so he doesn’t ever stop! Whereas my previous Canicross dog would self-regulate a lot more. He would get to ten degrees C and go, you know what? I’m too hot, so I’m just going to trot a long and not really pull. I was much less worried about him because he had the ability to decide when he was not as comfortable. He was never at as much risk as my pointers are because they have that greater desire to run and they do get very hot. I will always run them in the shade, near water and in cooler temperatures during the summer.
Even if your dog self-regulates, if you take your typical Canicrossing dog and you are running in a group, it is very easy for the dog to get carried away trying to keep up with the others.
ANNE: Yes, that is definitely something to consider. If you are thinking whether or not to go out and you are planning to run with a group, if it is actually quite warm, could you change plans and go out for a plod on your own instead? Rather than going out in a group where the dogs tend to see other dogs and want to chase and where you might not have as much control over the chosen route or distance. Go out early, cut it short if necessary and give the dog a break. Decide if they can manage to go on or if you need to turn back. You can sometimes do that a bit more easily on your own.
Running in a group gives you that whole social aspect for sure, but you know your own dog. It’s the same with nutrition. Despite what other people are doing, you should always be loyal to what your dog needs at any given time and not be swayed by other people’s opinions.
To conclude, Anne, you’re a regular Canicrosser. What would you say to people considering starting the sport?
ANNE: I would say that the biggest risk is how addictive it is! I am a complete non-runner who started running with a friend’s dog about 13 years ago. Now, I’m about to go back up to running with four dogs and I absolutely love it. It gives me a wonderful bond and relationship with my dogs and it is so much fun.
We have talked a lot about risks and things to be mindful of. However, it’s all about having that knowledge in place so you can have a safe and enjoyable run, rather than putting people off Canicrossing altogether! If you’re just starting out with your dog, begin with the cooler temperatures and cooler times of the day. Avoid going out when the sun comes out and the day really starts to heat up. You can always switch to Canitrekking – hands-free walking with the harness and kit – and then build up to running when the conditions are more conducive to it.
For more information visit Hot Dogs.
A must read: Anna and Emily have written this excellent article on tips for cooling an overheated dog.