Yes you read that right, Emily’s inner crazy cat lady has been unleashed for today so we’re talking about frazzled felines for a change!
Can cats get heatstroke?
In a word, YES! Any animal can develop heatstroke, we just tend to think about dogs and horses because they are the animals most frequently featured in the news, and we exercise and travel with these species meaning they are more commonly put in a situation that can result in over-heating. Whilst cats tend to be heat-seekers – lying on radiators, in patches of sunlight and in front of fires – they too can find themselves in trouble in hot weather.
Which cats are at risk?
One of the most serious risks to cats in hot weather is becoming trapped somewhere hot. The majority of UK cats enjoy a free roaming indoor-outdoor lifestyle, meaning they can seek out warm areas to sleep such as greenhouses, sheds and conservatories. If they fall asleep and find themselves trapped, just like dogs in hot cars they will struggle to control their body temperature and develop heatstroke if they cannot escape.
Older cats, just like dogs and humans, are likely to be at greater risk of heatstroke. Any underlying health conditions like obesity, heart disease, thyroid disease, kidney disease or breathing disorders will make it harder for them to cool down. Dehydration is particularly dangerous in hot weather, and older cats may be less inclined to drink so encouraging fluid intake is really important (see below) in hot weather.
There are rare reports of cats developing heat-related illness from hunting behaviour, chasing birds that have entered a hot house or apartment for example, but unlike dogs exercise is far less likely to cause a problem to cats, as they’re (mostly) not stupid enough to run around in the heat.
Cats will develop heatstroke if trapped, or travelling in a hot car. So if you do need to travel with your cat for any reason ensure you are prepared to keep them cool during the journey:
Consider packing ice packs/frozen water bottles that can be wrapped in a towel to provide a cooling mechanism
Make sure you can create shade from the sun
Have access to water and a water bowl if there is a chance the journey could be long or delayed due to traffic
Ideally travel in the cooler parts of the day
If you don’t have air conditioning, ensure your cat is restrained in an appropriate carrier so the windows can be opened
Keeping hot cats cool
Keeping your cat hydrated is one key thing you can do to help them in hot weather. Cats are very particular about what they drink, so it’s worth being aware of your cat’s preference for water type, bowl type and location, and considering how they access their water.
Simply adding a few extra water bowls to different locations around the house and garden can help to improve your cat’s water intake, especially if you have an older cat or a cat with mobility problems. If you have multiple cats in your household then ensuring they have water bowls to spare is essential. Consider where you position the water bowls, easy access is important if your cat struggles to jump, and distance from food bowls and litter trays is important.
You can add ice cubes to your cat’s water bowl, but consider adding them to an additional bowl just in case your cat decides they don’t like them. If your cat has dental disease ice water may actually stop them from drinking (Emily knew Leo needed a dental when he stopped wanting to eat his ice cream). Some cats may enjoy using an ice cube as a toy.
Water fountains can be great for encouraging fussy cats to drink, Leo the cat definitely prefers running water so this was about 30 seconds after Emily first set up his water fountain:
Prior to the water fountain Leo would ask to have the tap put on so he could drink straight from the spout:
There are some liquid diets for cats that may help to increase fluid intake, Leo received this one as a free sample in the post and he was VERY impressed. You can also consider freezing liquid foods and treats like this to provide a cooling snack to keep your cat entertained.
Shaded areas in gardens are ideal places for cats to keep cool, if your cat is indoor only then stone floors or cooling mats can provide ideal cool locations for them to chill if it gets too hot. Some cats will seek out cooler places to nap, and may even tolerate ice packs/frozen water bottles wrapped in a towel to cool their toes.
Cats are particularly prone to sunburn and can develop skin cancer as a result, so if you have a cat with pink ears like Leo, consider using feline sunscreen to keep them safe when sunbathing.
How to spot signs of heatstroke in cats
The signs of heatstroke in cats are very similar to those in dogs as the underlying disease process is the same. If you are at all concerned about your cat you should contact your vet immediately, just like dogs the sooner your cat is treated the more likely it is they will survive.
Early signs may include:
Panting – open mouth breathing in cats is NOT NORMAL and should alert you that something is not right
Excessive sleepiness and confusion – we all know cats like to sleep but if you are struggling to wake them, or they are not responding normally to things like treats or fuss this can be a sign of over heating
More serious signs include:
Passing vomit or diarrhoea with blood
Becoming wobbly and uncoordinated
A cat’s normal body temperature is 36.7–38.9°C, so if your cat has collapsed and you can check their temperature, anything over 40-41°C warrants active cooling. Move them away from the heat into the shade, use water to wet their coat and feet and use air movement (fans or air conditioning) and get them to your vet as soon as possible.
Leo and most of the cats at the animal unit at Brackenhurst have temperature sensing microchips so that Emily can monitor their temperature and these can be handy for detecting early problems, but a rectal temperature should be checked if your cat is unwell.
Finally, heatstroke is far less common in cats than it is in dogs. Cats are smaller, which helps with heat loss, and cats are rarely dragged out on walks during the hottest part of the day! In particularly hot weather you may want to consider keeping your cat indoors to reduce the chances of them becoming trapped somewhere hot, but most cats are probably enjoying the current hot weather, and looking blissfully relaxed whilst doing so.
As the UK temperatures continue to climb, it is essential every dog owner knows how to recognise the signs of heat-related illness, and how to effectively cool their dog in an emergency. Whilst these presentations are aimed at veterinary professionals, we’re making them available here too for anyone who is interested in our work.
ALWAYS seek veterinary advice if you are concerned your dog has developed heat-related illness. Less than half of the dogs that progressed to the severe form survived, so getting effective, early treatment is crucial.
Lots of myths get shared about cooling hot dogs, and sadly there isn’t much published evidence on which cooling methods work best! Our current understanding is that if your dog has overheated, but is still conscious, the most effective methods of cooling are to either immerse them in water (cold tap water is perfect), or wet them (with whatever water you have available) and fan them – air conditioning is perfect if you’re transporting them to the vet. If your dog has overheated and has lost consciousness, it is ESSENTIAL that you protect their airway, and don’t let them inhale any water. Dogs that have lost consciousness will cool far more slowly, so it is even more important to use effective cooling methods, such as spraying with water plus air movement.
Cooling methods used in dogs with heat-related illness under UK primary veterinary care during 2016-2018.
In this presentation, Emily shares the provisional results of our study exploring the cooling methods reported to have been used in the veterinary records of UK dogs presenting to their vet with heat-related illness. We also present the current evidence-base for cooling methods that are available for hot dogs, and discuss the importance of effective cooling.
VetCompass Clinical Grading Tool for Heat-related Illness in Dogs – a novel tool to support clinical decision-making in primary-care practice.
In this abstract, Emily introduces our VetCompass Clinical Grading tool, which we hope will allow dog owners and veterinary professionals to recognise heat-related illness earlier, and hopefully support more effective management of this life-threatening condition.
We’ve condensed our research so far into an article for the Kennel Club, sharing updates on the recognition of heat-related illness in dogs, the breeds at risk, and the most common triggers of this life-threatening condition.
First published in the May 2021 edition of the Kennel Gazette. Copyright The Kennel Club Limited. Reproduced with their permission.
As summer finally arrives, we’re asking all dog owners to remember that
Dogs die in hot cars and on hot walks!
If your dog’s exercise has been limited by the UK’s lockdowns, or they have perhaps developed a little “lockdown bulge” they will be at greater risk of developing heat-related illness as the weather starts to warm. So make sure you can recognise the early signs, and always have a plan to cool your dog in an emergency.
Our latest paper reports the most common signs of heat-related illness in dogs, abnormal breathing (excessive panting, and/or difficulty breathing) and lethargy (unwillingness to exercise, play or interact, changes in behaviour and tiredness). Crucially, dogs that are presented to vets showing just these early signs, were far more likely to survive.
When dogs presented to their vet with signs of severe heatstroke (neurological changes including multiple seizures, loss of consciousness or being comatose, bleeding disorders including passing vomit or diarrhea with blood, and organ damage), less than half survived (just 43.2%).
We are urging ALL dog owners to familiarise themselves with the EARLY signs of heat-related illness, as spotting these and taking appropriate action – cool your dog and seek veterinary advice – could save your dog’s life!
The AMAZING Camilla from the VetCompass team has turned our findings into this brilliant info-graphic, which we encourage you to download in full and share with as many dog owners as possible, as the UK weather starts to turn warmer!
We will be presenting this tool in the BSAVA 2021 Clinical Abstracts in May, and will be sharing our findings on cooling methods used by UK vets, so watch this space for more updates over the coming months!
Almost exactly two years ago we published our post – Dogs don’t just die in hot cars (to date our most widely read blog post!). Amidst the usual summer “Dogs die in hot cars” campaigns we warned owners about the risk of heat stroke triggered by exercise, and shared a particularly heart breaking story from a trainer who lost his dog after a seemingly routine training session in mild heat. We can now share an update on this important message, including the dogs most likely to be affected by exertional heat-related illness – aka heat stroke following exercise.
Of the events where a trigger was recorded in the history, 74.2% occurred after exercise.
Exposure to hot weather alone triggered 12.9% of events and travel or confinement in a hot car triggered 5.2% of heat-related illness events. Other triggers included confinement in a hot building (e.g. a conservatory), undergoing treatment at a veterinary clinic or professional grooming parlour, and sadly becoming entangled in blankets or bedding.
The risk of death following exercise induced heat stroke was similar to the risk of death following vehicular heat stroke, with around 10% of events resulting in fatality. The risk of death following heat stroke triggered by confinement in a hot building was significantly higher, with a third (33.3%) of events resulting in the dog’s death.
Exercise triggered over 10 times as many canine heat-related illness events as hot cars, and caused 8 times as many deaths.
The risk is year-round!
A key result from this project was the year-round risk of exercise induced heat stroke. Exertional heat-related illness affected dogs during every month of the year, with fatalities in January and every month between March-October.
In contrast, vehicular heat-related illness and environmental heat-related illness occurred only between March and September (the UK’s spring to summer period). This mirrors the results we reported earlier this month, that internal car temperatures exceed 35°C between April and September . Vehicular heat stroke deaths occurred between March and July, adding further evidence to support our recent call to launch the “Dogs die in hot cars” campaign earlier in the year. Environmental heat stroke deaths occurred from May to September, and building entrapment fatalities occurred between June and September.
Which dogs are most likely to develop exertional heat stroke?
We previously reported that Labrador Retrievers had no greater risk than crossbred dogs for developing heat-related illness in general. However, this is not true for purely exertional heat-related illness, Labradors were twice as likely to suffer from the condition. The Chow Chow, Bulldog, French Bulldog, Greyhound, Springer Spaniel, Cavalier King Charles Spaniel and Staffordshire Bull Terrier were all found to be at increased risk of exertional heat-related illness when compared to the Labrador, with these breeds plus the Pug, Boxer, Golden Retriever and Border Collie at increased risk when compared to crossbred dogs.
Younger dogs (under 8 years old) were at increased risk of exertional heat-related illness, as were male dogs and neutered dogs. Overweight (both obese and large for their breed) dogs were also at increased risk, as were brachycephalic dogs in general.
This finding reflects the situation in humans, with young athletic men at greatest risk of exertional heat stroke, either following sport or after working in hot environments.
Which dogs are most affected by hot weather?
The breeds most at risk of environmental heat stroke – heat-related illness occurring after being exposed to hot weather alone without exercise – were the Chow Chow, Bulldog, Pug and French Bulldog. Again, dogs were found to have similar risk factors to humans for environmental heat stroke, with older dogs (aged 12 years or over) 3 times as likely to develop the condition.
The risk to flat-faced dogs
Brachycephalic, or flat-faced dogs, had two times the risk of environmental heat stroke and three times the risk of vehicular heat stroke when compared to mesocephalic dogs (e.g. those with a medium skull shape, like the Labrador or Springer Spaniels).
Flat-faced dogs are known to overheat at relatively low ambient temperatures (e.g. 21-22°C ), due to their limited capacity to cool via panting. Our findings suggest they are at increased risk of all types of heat-related illness, so efforts to change current breed standards and “breed to breathe” should be prioritised in the face of rising global temperatures.
How do you keep your dog safe?
The crucial thing is to know your dog.
Be able to recognise when your dog is getting hot – are they starting to pant, lying down more, seeking shade and cool surfaces to lie on. Know if your dog will run until they collapse, as these “eager to please” dogs like the Golden Retriever, Springer Spaniel and Staffordshire Bull Terrier are particularly at risk when out walking, running or even playing in warm weather.
If you own a flat-faced dog you need to be extra cautious in any situation where they could be exercising or exposed to a hot environment. Consider carrying water with you so you have a means of cooling them if you need to.
If your dog is older, you need to be particularly cautious in hot weather. Just like humans, older dogs struggle to control their body temperature in hot weather, so you need to check that your dog is actually drinking enough, keep an eye on them sunbathing in hot weather, and consider using paddling pools and frozen treats to help them stay cool.
Dogs die in hot cars, but in the UK more dogs die after exercise, even during cooler months. Think carefully before taking your dog on a long walk in hot weather, and if you’re heading to the beach, make sure you can keep them cool and out of the sun.
Our latest study looked at temperatures falling outside the range of 8-25°C . Broadly speaking, 25°C is the upper comfortable threshold for dogs to control their body temperature, slightly above the upper limit for some brachycephalic dogs to cool themselves unaided. This range is also the temperature threshold for the storage of many veterinary and human drugs, outside of which they can lose their efficacy with potentially dangerous consequences. An additional threshold over 35°C was included, at which point all dogs struggle to thermoregulate, particularly when enclosed in a car with no air movement.
The internal temperatures of four cars were monitored over a two-year period. This allowed us to monitor the temperatures 24 hours a day (no dogs were kept in the cars for the purposes of the study!). By the end of the study period, we had between 7300 and 17800 individual temperature readings for each month of the year. This allowed us to look at the impact of time of day and seasonality on internal car temperature.
UK car temperatures
Internal car temperature ranged from -7.4°C to 54.5°C with temperatures dropping below 8°C in every month except June and July. Temperatures exceeded 25°C in every month of the year and above 35°C from April to September. And whilst early mornings were generally cooler, temperatures over 35°C were recorded between 8am and 9pm.
The highest temperature recorded was 54.5°C
It is also worth bearing in mind that the risk may extend beyond stationary vehicles. Sitting in traffic on a hot day, or an air conditioning system failure could also be lethal for dogs trapped in the car.
This study highlights the year round risk to dogs in cars and the need for constant vigilance. This is particularly the case for those breeds and types of dogs considered more at risk of heatstroke, such as brachycephalic, overweight and older dogs.
The study highlights that the risk to dogs in cars is year round, not just restricted to the traditionally warmer summer months. Heat-related illness can be fatal so whenever dogs are in cars, owners should be cautious. Whilst traditionally the advice is to avoid exercise during the midday heat, peak car temperatures occurred between 14:00 and 17:00 hours from March to October. So late afternoon, from spring to autumn is the most at dangerous time for dogs in cars.
You may have been wondering where we’ve been and what we’ve been up to, as it seems an age since we last shared any updates on our canine heatstroke research project…
Well, we finally have some exciting news!
Hot Dogs at BSAVA Congress 2020
Last month Emily presented two abstracts (preliminary findings) at the British Small Animal Veterinary Association’s annual Congress. Whilst the live event was an early casualty to the COVID19 lockdown, the abstract session was moved on-line in May, reaching a virtual audience of over 160 veterinary professionals from around the world.
The first abstract summarised our first study using the VetCompass TM database, reviewing the anonymised veterinary records of over 900,000 UK dogs to explore canine risk factors for heat-related illness. This abstract can be downloaded in text form below, or you can watch a recording of the presentation.
The second abstract explored the “triggers” for heat-related illness in UK dogs, reporting the most common reasons dogs develop heatstroke, and which reasons had the highest risk of causing death. This abstract can be downloaded in text form below, we hope to be able to share the video soon.
Findings from our VetCompass study will be published 18th June at 4pm!
Finally, our first Hot Dogs VetCompass study will be published TOMORROW AFTERNOON, where we report the incidence, fatality rate and canine risk factors for heat-related illness in UK dogs (the full paper of the first abstract). Thanks to a Dogs Trust Canine Welfare Grant this paper is Open Access, meaning you will be able to read the full version for free just as soon as it is published!
Watch this space for updates, we’re hoping it’s going to be a busy summer sharing our research, to help you make safer choices for your dog.
The average car is a metal box with glass windows. Metal is an excellent conductor of heat, meaning heat can pass through metal easily, think of your kitchen saucepans. Glass is a poor heat conductor but allows sunlight to pass through. This means that light energy from the sunlight enters the car through the windows but then gets trapped as heat by the glass. Some of this heat will be lost through radiation and conduction into the surrounding air, but if sunlight continues to fall on the car, it will continue to heat and in summer, this happens far quicker than heat can be lost to the environment; the reason greenhouses are so effective. The net result is your classic summer hot car.
The typical British summer is an unpredictable affair. Whilst temperatures regularly reach 20oC or more, often we have consistent cloud cover, intermittent rain or high winds to keep things feeling fresh, and stop cars turning into ovens. Last summer, we experienced one of the first prolonged heatwaves of this century, with temperatures regularly hitting 30oC and endless blue, cloudless skies. We have become complacent. Our dogs are typically part of our family, so we like to take them with us, whether we are taking them for a walk, for a day out, or travelling somewhere. The problem is, on a typical sunny day of 21oC, your average family car will reach temperatures of 31oC in 10 min. As the outside temperature climes to 31°C, the internal temperature of the car can reach 54°C. 80% of that temperature rise happens in the first 30 minutes.
We’ve all seen the adverts, surely no one would be so stupid…?
Since 2016, summer has been heralded by the “dogs die in hot cars” campaigns supported by a number of charities to increase awareness of the risk of leaving dogs in cars in the summer, and yet last year (2018) the RSPCA received 8290 calls, an increase from around 7800 calls concerning heat exposure in animals 2017. In a single weekend, over the 2018 May Bank holiday weekend, 217 calls were made by people concerned about dogs left in hot cars. One London police force was even offering a ‘free ventilation service’ if dogs were left in cars during the hot weather (by breaking the window).
So why do people leave dogs in hot cars? A two-minute trip into the shop for a couple of forgotten items can easily become ten minutes. When questioned, owners gave a range of excuses, from “My dog is white, he’ll be fine” to “We feel bad leaving him at home on his own all day.” “We didn’t think we’d be long.” “It’s OK, I’m a vet”. No doubt, the vast majority of people do not want to harm their dog, but simply do not think. When leaving the car, the air con or open windows from travelling can make the car feel relatively cool. However, left in the sun for any length of time, even with the windows cracked slightly, it will get hot. Shade can help to keep the car cooler, but as the sun moves round, the shade can quickly disappear.
A human in a similar situation would begin to sweat to try and lose heat. Dogs don’t have the ability to sweat, they will pant, but as the temperature continues to rise, panting becomes less effective, and once the car temperature exceeds body temperature (around 38oC) there is nothing the dog can do to cool down. Unless the dog is actively cooled (see below) their body temperature will rise with the car temperature, and once they exceed 41oC, they are likely to develop heatstroke.
Heatstroke – the problem
Heatstroke isn’t the same thing as sun stroke, or heat cramps, or heat exhaustion. These conditions can often be treated with cooling, plenty of fluids and rest. True heatstroke causes multi-organ failure. Picture an egg in a frying pan, you crack the egg, the yolk is yellow but the egg white is clear and jelly like. Once the egg starts to heat, the chemical structures of the proteins start to change, the egg white becomes firm and changes colour. Now imagine this happening to the proteins within the body. As body temperature exceeds 41oC the stomach and intestines stop functioning, so the dog may vomit or pass bloody diarrhoea. The kidneys stop working, so despite fluid therapy the dog is unable to flush out the toxins from all the cellular damage taking place around the body. If the dog’s brain overheats, they may start fitting, or fall into a coma. The mortality rate for dogs with heatstroke is up to 63%.
Don’t risk it.
Don’t keep your dog in the car and never leave them unattended. Even in the shade, car temperatures can increase quickly, and shade may disappear. Leaving windows partially open has little effect on car temperature. If you are stuck in traffic or travelling, have the air conditioning on to keep the car cool and make sure windows are shaded from direct sunlight. Don’t assume your dog in the car boot area is fine because you are, check them regularly, your air conditioning may not reach the boot. Ideally, leave your dog at home in hot weather. Car shields and shades may help to keep the car cool by reflecting the sun’s rays, but some may also act as an insulator, particularly if the car is already hot inside. If you have no alternative other than to keep your dog in the car, open all windows, open the boot, try and maintain airflow, park in shade, and don’t leave your dog. Stay with them so you can be absolutely sure they are OK.
If you see a dog in a hot car, the advice is to phone the police. Heatstroke can kill quickly. A dog that is suffering from heatstroke needs to be actively cooled and taken to the vets. Active cooling is key. Even before setting off to the vets, use water to splash the dog’s legs, belly and throat area, get them out of the sun and into the shade, and if possible move them somewhere with good air flow – this might be in a car with the air conditioning already blowing. To give you an idea, the army have been known to use the downdraft from helicopter rotor blades to create airflow over soldiers with heatstroke. Next, getting to the vets as quickly as possible is the current best advice. Avoid using ice or very cold water, as this can do more harm. When your skin is cold, the blood vessels constrict, which can make it harder to cool the dog, and increase the risk of them going into circulatory collapse (shock).
There is no guarantee any dog will survive heatstroke, so the best way to keep your dog safe is to prevent it.
The Hot Dog’s team (Emily and Anne) are now working with Dan O’Neill from the Royal Veterinary College on a UK wide canine heatstroke study. The study will use data from the Vet Compass™ database to review the clinical records of over 900,000 dogs registered with UK primary-care veterinary practices for heatstroke events. As well as canine risk factors (e.g. breed, age, sex and bodyweight), additional information will be collected to establish the incidence, fatality rate, seasonality and underlying causes for canine heatstroke. Understanding the risk factors of heatstroke specific to the UK dog population will provide evidence to better support educational campaigns aiming to reduce or prevent this potentially fatal condition.