How to avoid heat stroke in pigs (1)

Pig Sunburns, Heatstroke, Heat Stress: Pig Summer Heat Care


With a sizzlingly hot summer on the cards, we’re all going to be looking for effective ways to cool down. Unlike humans, pigs have very few sweat glands, and those it does have aren’t particularly effective for temperature control. 

Are pigs prone to heat stress? Pigs are more likely to develop heat stress because of their inability to sweat.  When pigs have little access to water, mud, or shade, they have a more difficult time cooling down. Heat stress affects pigs’ growth rate and decreases feed intake. It can also turn into heatstroke if it’s not treated soon. 

Their lungs are also comparatively small compared to their body size. This makes it difficult for them to remove excess heat by panting.

Pigs suffer from three main issues during the hot summer months – heat stress, heatstroke, and sunburn. Here, we will look at how to prevent, diagnose, and treat each of these potentially dangerous conditions. 

Keep Cool and Protect Your Pigs From Heat Stress

Pigs can’t sweat effectively enough to cool themselves down in hot weather. Most animals that can’t sweat effectively turn to panting to lower their body temperatures, but pigs’ lungs are too small to make this very effective either. These physiological limitations make them highly prone to heat stress. The layer of thick subcutaneous fat insulating their bodies doesn’t help either!  

Symptoms and Complications of Heat Stress in Pigs

The first signs of a heat-stressed pig are:

  • Rapid breathing 
  • Loss of appetite 

If the problem continues, pigs may develop one or more of the following symptoms: 

  • Excessive thirst
  • Diarrhea 
  • Vomiting 
  • Muscle tremors
  • Weakness 

Aside from the immediate symptoms, heat stress compromises the pig’s internal functions. A study conducted in 2013 found that excessive heat exposure reduces a pig’s “intestinal integrity and post-absorptive energetics.” These problems can have a long-term effect on the pig’s overall well-being and may be fatal. 

Pigs can suffer heat stress when the ambient temperature rises above 82.4℉. High humidity coupled with higher temperatures increases heat stress, especially among breeding herds with a lower temperature tolerance.

Pigs need wallows in hot weather
Pigs need to wallow during hot weather

Shade and Water Are Key To Preventing Heat Stress 

If a pig is to avoid getting heat stress in these circumstances, it needs:

  • Shade
  • Good ventilation
  • Cool drinking water, ideally of around 50℉ or less
  • Access to a wallow

In intensive pig farming scenarios, it’s also helpful to use a spray cooling system to lower the temperature of your livestock. Reducing your stocking density can also lower the ambient temperature and increase airflow.

Avoid feeding your pigs excess fiber on hot days as the intestinal fermentation process needed to digest it produces body heat. You can also provide your pig with smaller meals more frequently and lower the crude protein content. Research shows that, during digestion, “proteins generate more metabolic heat than fats (26% against 9%).”

Giving your pigs electrolytes and antioxidants in their water supply can also stave off the first signs of heat stress. You can also supplement their feed with antioxidants like vitamin E and betaine. 

The Dos and Don’ts of Treating Pigs with Heat Stress 

  • DO Apply a cool, wet towel to the back of your pig’s neck 
  • DON’T throw cold water over your pig – this could cause potentially fatal shock
  • DO offer popsicles and ice cubes for your pig to eat
  • DON’T force your pig to drink
  • DO put diluted vinegar (50% apple cider vinegar, 50% water) on your pig as it has a faster evaporation rate than water and will therefore reduce its body temperature more effectively. 
  • DO offer your pig electrolytes to minimize the impacts of heat stress.

In Pigs, Heat Stress Can Quickly Escalate into Heat Stroke

Heat stress is often a precursor to a critical condition known as heat stroke. Heatstroke occurs when the core body temperature rises above 109.4℉. At this point, the pig’s natural temperature control mechanisms fail. 

As with all warm-blooded animals, pigs are a homeothermic species. That means they have a metabolic process of thermoregulation that enables them to maintain a stable internal temperature even when the ambient temperature varies.

Unfortunately, pigs have a high body weight to surface area ratio, making it more difficult to cool down when the external temperature rises. 

Pigs also have a thick layer of subcutaneous fat that acts as an insulator. 

Only capable of sweating through the snout, if a pig cannot wallow, it will struggle to lose heat from the skin. Even pigs with access to a wallow are susceptible to heatstroke in high humidity. When the humidity is very high, the water on the pig’s skin won’t evaporate, so it will fail to provide the cooling processes required.  

In situations like these, pigs rely on shade, airflow, and panting to reduce their body temperature, but these processes aren’t effective enough to prevent heatstroke in extreme heat and humidity. 

Signs your Pig is Suffering from Heat Stroke 

How do you tell if a pig is overheated? Pigs suffering from heatstroke pant rapidly and heavier than usual. Their drool becomes thick and stringy. You may notice glazed eyes and white gums. They will also attempt to lie on their sides and isolate themselves from other pigs. As the respiratory rate rises, the pig loses even more water, increasing the risk of dehydration.   

The symptoms of heatstroke are similar to the signs of heat stress and include:

  • Panting
  • Lethargy
  • Weight loss
  • Loss of appetite
  • Diarrhea 
  • Increased urination
  • Excessive water consumption
  • Reducing growth in young livestock
  • Reduced milk production in lactating sows 
  • Muscle weakness

In extreme cases, heatstroke can cause heart failure and subsequent death. 

6 Steps to Reducing the Risk of Heat Stroke in Pigs 

To reduce the risk of heatstroke in free-ranging pigs: 

#1 Shade Helps to Prevent Heat Stroke

Provide plenty of shade in the form of either natural or artificial structures. These can include trees, shelters, and even simple facilities made of shade cloth or galvanized steel sheets. Ideally, these should be situated where there is plenty of natural airflow. 

Shade helps prevent heat stroke

#2 Wallows are Essential on Hot Days

Create wallows that offer your pig as much mud as water. A pig can protect its skin from the sun by coating itself in thick mud. 

On hot days, wallows will quickly dry up, so they will need topping up throughout the day. 


#3 Unlimited Drinking Water is Critical for a Pig’s Health

Provide unlimited, fresh drinking water to prevent heatstroke and other heat-related conditions. Position your troughs in the shade to keep the water temperature down. On scorching days, you can add ice blocks to reduce the water temperature further and limit evaporation. 

#4 Smaller, More Frequent Meals Help Cool Your Pig

As we mentioned earlier, a pig’s digestion produces heat, especially when breaking down fiber and protein. Smaller, more frequent meals will put less pressure on your pig’s digestive system, so it won’t have to work as hard or produce as much metabolic heat. 

You can also add water to the feed to make it easier to digest.

#5 Reduce Fiber Intake to Lower the Body Temperature

Most fibers are difficult to digest. If undigested, that fiber moves straight to the pig’s large intestine. There, it stimulates the fermentation process, which in turn generates heat. 

Replacing fiber with fat can help lower your pig’s body temperature simply because it’s easier to digest and generates less metabolic heat.   

#6 Provide Electrolytic Support

As a pig’s temperature increases, its respiratory rate quickens. This rapid breathing causes the pig to lose more carbon dioxide from its bloodstream, causing its appetite to wane.

Electrolytes containing sodium bicarbonate or potassium can help restore the pig’s natural balance and boost feed intake. 

Treating a Pig with Heat Stroke 

The first aid response to heatstroke is much the same as for heat stress. Reducing the pig’s body temperature gradually and keeping it hydrated can prevent heat stroke from becoming life-threatening. 

Sunburn Is a Common Summer Problem for Pigs

Heat stress is just one of the problems facing pig owners this summer. Pigs are also prone to sunburn, which manifests itself in much the same way as in humans. More likely to affect white-skinned pigs, like the Yorkshire and Landrace, sunburn can be a problem for any pig, causing the skin to redden, blister, and scab.


This condition can be excruciating for the pig and, if left untreated, can lead to more severe health problems. These include:

Localized infections – if the pig’s skin is broken or cracked, it provides a way for bacteria and other microorganisms to enter the body. Such cracking can lead to localized skin infections.

Heatstroke – sunburn and heat stroke often go hand in hand. If you see signs of sunburn, look out for indications of heatstroke. These include an increased respiratory rate, dehydration, diarrhea, vomiting, and muscle weakness.

High parasitic load – sunburn weakens the pig’s skin, increasing the risk of skin penetration by both internal and external parasites. A sunburnt pig is more liable to pick up threadworms and   

Pregnancy loss – the pain and discomfort associated with sunburn can lead to abortion or a sow refusing to be covered.

Skin cancer – relatively common and potentially life-threatening, skin cancer from UV exposure can be expensive and difficult to treat. 

Large, white pigs are more prone to sunburn

Two Ways to Prevent Sunburn in Pigs

You can prevent your pigs from sunburning by providing a muddy place where they can coat their skin and block the sun’s UV rays. Sunscreen will do the same thing and help prevent your pig from getting sunburned. 

Mud Protects a Pig’s Skin from UV Rays

Although clean water will enable a pig to cool off, it won’t do much to prevent it from getting burnt by the sun. Therefore, a muddy wallow is preferable as it enables the pig to coat itself in a thick layer of sticky mud that the sun can’t penetrate.

Sunscreen Can Prevent Sunburn in Pigs

Large, white pig breeds, including the Landrace and Yorkshire, are more prone to developing sunburn than other breeds. For them, mud may not be enough, and you may need to apply sunscreen regularly to protect their sensitive skin. 

Coating several 700lb pigs in sunscreen may not be very cost-effective, but it will protect them against sunburn. 

Commercial pig sunscreens are available, including natural and organic products like this Swine Shine Sunscreen SPF 50. Unfortunately, human sunscreens aren’t approved for use on livestock, so your options are either shelling out a fortune on commercial pig sunscreen or making your own. 

How to Make Pig-Safe Sunscreen 

This first recipe for pig-safe sunscreen is my own invention, and it’s a bit of a cheat. I have no idea whether it would pass the stringent requirements for animal topical medicine or not, so please use it with caution. 

#1 Simple DYI Recipe for Pig Sunscreen



Combine ingredients and apply liberally, focusing on susceptible areas like the ears and neck. The zinc oxide scatters the sun’s rays, preventing potential damaging UV radiation. The nappy rash cream helps reduce irritation and acts as a carrier ointment for the active ingredients. 

#2 The Best All-Natural Recipe for Pig Sunscreen 



  • Melt the avocado oil, beeswax, cocoa butter, and coconut oil in a double boiler or by using a bowl suspended over a pot of boiling water. 
  • Remove mixture from the heat and allow to cool, stirring it periodically
  • Add the zinc oxide powder and whisk thoroughly
  • Transfer to a storage container and apply as needed.

Treating Sunburn in Pigs 

Sunburn can be excruciating, so anything you can do to soothe the irritated skin will help your pig. You can make your pig more comfortable by applying topical treatments, such as aloe vera gel or comfrey balm. A veterinarian may prescribe anti-inflammatories to reduce pain and swelling in more severe cases. 

Frequently Asked Questions

How hot is too hot for pigs? Temperatures over 80°F is too hot for pigs. 85°F and higher can become very dangerous for larger pigs who can’t cool down. During hot weather pigs should have shade and water access. Larger pigs will struggle to cool down more than piglets. Pigs are most comfortable in temperatures of 50-75°F. 

Are pigs temperature sensitive? Pigs are more temperature sensitive than many other animals because they don’t have many sweat glands. Additionally, they have a high level of fat to their skin (surface) area which makes it even harder for them to cool down. Pigs will often overheat sooner than other animals of similar sizes. 

Do pigs prefer the sun or the shade? During the summer, pigs prefer shade because they have difficulty cooling down. However, on cold days pigs usually prefer the sun so that they can warm up. Pigs struggle more to cool down than to warm up because they have more insulation in the form of higher fat stores than many mammals. 

Can I spray my pig with water? Spraying pigs with cold water can cause shock to their systems, but offering a sprinkler so pigs can get wet willingly is a good idea. Sprinklers encourage pigs to wallow in the mud and provide a means of cooling down. Sprinkers are better than misters, which increase the humidity and make it harder for pigs to cool off. 

How do you treat heatstroke in pigs? Pigs with heatstress should be cooled down quickly with cold water, a cool, wet towel on the back of their neck, and access to shade and mud. Frozen food can be fed to help cool pigs down. Pigs should also have enough space away from other pigs to get good airflow. 


Summer is a trying for pigs and their owners. Unable to sweat effectively, pigs struggle to lower their body temperatures in hot, humid weather. Their high body weight to surface area ratio and thick subcutaneous fat layer don’t do them any favors. To keep your pigs healthy this summer, make sure they have plenty of fresh water, muddy wallows, and shady areas. You can also adapt your feeding regime to reduce the risk of heat stress.    

My Most Used Pig Supplies

This list contains affiliate products. Affiliate products do not cost more but helps to support BestFarmAnimals and our goal to provide farm animal owners with accurate and helpful information.

Purina Pig Chow will last well (or Mazuri is popular, but I haven’t tried it), and the stainless steel non-skid bowls that will help keep the mess down.

A pig blanket to keep her warm. This one also has bright colors and helps to provide rooting without the destruction.

Pig Harness for walking and handling your pig. There are a lot to choose from, but this one is pretty easy to use. If you want one that has a separate leash, this looks like a good one.

A large crate for keeping her safe in your house at night and when you leave the house. This is essential. You’ll also want a litterbox, and I like mine with a lid for nighttime. Pine shavings are best, and you may be able to find them in larger quantities locally.

When you have accidents, Odoban will help eliminate odors. When you are potty training, these floor pads work great for keeping your house clean while training her to go in certain places.

You’ll also want an outdoor house to keep her warm when she gets outside time, an essential part of her development.

Dewormer- Ivermectin is the primary dewormer I use, although I do rotate with a non-ivermect ingredient once so that the worms don’t get immune to it.

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