By: Dr. Emma Bush
The start of the summer is an exciting time for pets and owners alike. Warm days mean beautiful hikes, swims and time spent together outdoors. Unfortunately, along with the warmth comes days of extreme temperatures and heat warnings. In times like these, the risk of heat stroke is a very real concern.
Heat stroke, otherwise known as hyperthermia and heat prostration, is a life threatening condition requiring immediate attention and treatment.
We often think of heat stroke as something that happens to a dog left in a car on a hot day, and this absolutely is a risk factor for heat stroke. However, heat stroke can also occur in outdoor areas with no shade and/or when pets are exercised in hot and humid conditions.
Some breeds and/or predispositions can increase risk as well; including pets that are obese and those with abnormal airways (such as brachycephalic dogs, who have narrower tracheas (windpipes)). In some cases, heat stroke (hyperthermia) can even occur secondary to health concerns including seizures, eclampsia and poisonings.
Due to behaviours and habits, dogs tend to suffer from heat stroke more than cats, as such, the rest of this blog post will address heat stroke in dogs. Of vital importance, second only to prevention, is knowing what heat stroke looks like so that we can address it when we see it. So, what does heat stroke look like?
Dogs suffering from heat stroke will start by panting. This is because, unlike people, they are unable to sweat and so use panting to regulate their body heat. This lack of an ability to sweat as much as humans do means that our pets are at higher risk of overheating. Panting can progress to restlessness and even distress. Other clinical signs can include, but are not limited to, unsteadiness, lethargy, disorientation, excessive drooling (hyper salivation), dry blue-purple or red gums secondary to inappropriate oxygenation and dehydration, vomiting and/or diarrhea, seizures, and sudden collapse.
If you see signs in your dog that make you concerned about heat stroke, the first thing to do is to remove your pet from the environment of concern. For example, you should remove your dog from the hot, unshaded area and should instead take them to a shaded and cool area and put a fan on in their vicinity. If you are able, you should also take their temperature (there are both rectal and ear thermometers that can be used on pets). You should also contact your veterinarian. In some cases, your family veterinarian may be able to provide the necessary care for your pet; however, in some cases they may advise you to go straight to an emergency hospital for more involved, around the clock care.
While preparing to and during transport to the hospital, you can wet ear flaps, stomach, armpits and paw pads with cool water using a direct fan for further cooling through evaporation. If using wet cloths, it is important to continuously replace these as they will obtain warmth from the patient and retain that heat. You can also offer cool water to drink, however do not force them to drink or force water in their mouths. There is a fine line where we do not want to overcool these patients as we can run the risk of driving them into a hypothermic zone. Because of this, regular temperature checks are important if possible.
Leading up to and during this time of transport, do not leave your pet unattended for any extended length of time due to the risk of more severe clinical signs listed above, including seizures and collapse.
Severe heat stroke can affect nearly every body system and can have systemic effects such as organ damage and changes to clotting abilities. Hyperthermia is a serious medical emergency and lowering the temperature alone does not resolve the large scale effects this can have on the body. Even if you are able to get the temperature into the normal range at home, your pet still needs to be seen by a veterinarian as there is still significant risk.
Heat stroke is commonly treated with IV fluids, mild sedation, oxygen therapy, and treating any other clinical signs that occur secondary to hyperthermia. For example, if seizures occur, anti-seizure medications would be used.
Outcomes for heat stroke patients vary depending on individual factors including the duration of exposure to extreme heat and how high their body temperature got. If it is a minor episode, most healthy pets should be able to recovery quite quickly if treated immediately. However, there is the risk of permanent organ damage and even death from secondary complications. Again, this is not a casual occurrence, it is a severe medical emergency.
Interestingly, pets that have experienced heat stroke are at a greater risk of developing it again in the future as the hyperthermia causes long-lasting changes to their thermoregulatory center! As such, if your pet has suffered from heat stroke once, even greater care must be taken to protect them from future episodes.
The key to avoiding heat stroke is by preventing risk factors as much as possible. Do not leave your pet unsupervised on hot days. When they are outside on hot days, ensure free access to shade and water. Avoid going for strenuous exercise with your pet on a hot day; and if going for a walk, elect to do so in early morning to later evening to avoid peak temperatures. For higher risk pets, as listed above, keep inside in an air conditioned area if possible, and only take outside for short bathroom breaks if possible on extremely hot days.
Heat stroke is something to be aware and cautious of, however, if taking necessary protections and precautions, it should be avoidable for any pet.
If you have any questions about heat stroke, or are concerned that your pet is suffering from heat stroke, please contact your veterinarian immediately.
References Used:
- Hyperthermia (heat stroke): First Aid:
https://veterinarypartner.vin.com/default.aspx?pid=19239&id=4951333 - VCA Heat Stroke in Dogs:
https://vcacanada.com/know-your-pet/heat-stroke-in-dogs
AAHA How Can I Prevent Heatstroke in my Pet?
https://www.aaha.org/your-pet/pet-owner-education/ask-aaha/how-can-i-prevent-heatstroke-in-my-pet/