The summer heat can be dangerous to horses, especially when it is made worse by high humidity. Horses can become dehydrated, lethargic and generally reluctant to work. Severe heat stress can cause colic, diarrhoea or collapse, so it is important to keep your horse cool. Young, old and ill horses are more vulnerable and must be monitored carefully.
Always think about the causes of overheating, which include the obvious, such as very hot weather, but there are also other causes, such as:
- Excessive exercise
- Prolonged exposure to direct sunlight or turnout without shade
- Poor ventilation in stabling
- Transporting over long distances
- Inappropriate rugs
A 500kg horse needs to drink 25 Litres of water daily in normal weather. This only goes up when the weather becomes warmer and your horse loses more water through sweating. Make sure your horse always has access to water, check automatic drinkers and outdoor water sources daily to make sure they’re filling and clean.
Some horses are less keen on drinking than others and may go off their water when away from home at competitions. It’s important to make sure you measure how much your horse has drunk. Horses also loose salts through sweating which may cause electrolyte imbalances which can affect your horse’s stamina.
You can try to improve your horses water intake by providing a ‘water buffet’ Alongside a bucket of normal clean water provide some water with table salt added and another bucket with a small amount of apple juice added to flavour the water. Some horses will prefer one or other of these options over plain water. Adding water to your horses feed can also improve their water uptake, as can offering warm water rather than cold.
When travelling away from home bringing water from home may be a good idea in order to improve your horses water uptake, some horses only like the flavour of water they’re used to.
Your horse needs somewhere in their field that they can hide from the flies and the heat. If your field has no trees around it then a field shelter is the best option to enable your horse to cool themselves down whilst out in the field.
Stables can provide shelter from the heat of the day but at the same time the air in stables can become very stationary. This can worsen breathing problems or just prevent your horse from cooling down. Well-designed stables have windows which will allow a draught to pass through the stable. Stables with poor ventilation will have more dust and cobwebs, the presence of lots of cobwebs in itself is not a problem, but it can let you know that the ventilation in your stable isn’t good.
To improve ventilation set up fans by the door.
Nobody wants to work hard in hot weather, horses are exactly the same. In order to improve your exercise time and to reduce the chance of your horse overheating making the most of the long summer days is the best plan. Aim to do most of your work before 10am or after 4pm to avoid the hottest time in the day. Finish your exercise with 10 minutes of low intensity work in walk to allow your horse to stretch out and cool down naturally.
After exercising it’s a good idea to wash down your horse with a hose or water buckets and sponges to cool them down faster. We have always been told to wash our horses and then scrape the water off afterwards with a sweat scraper. However, recent studies have shown that when trying to help your horse cool off its best to let the water evaporate off your horse without scraping it off. This cools your horse off in a similar way to the natural mechanism behind sweating.
Like exercise try to avoid travelling in the hottest time of the day, between 10am and 4pm. If this can’t be avoided, try to maximise ventilation in your lorry or trailer by opening any windows or vents. Provide water before and after travelling and if travelling for over 2 hours consider stopping halfway to offer your horse some water.
If your horse sweats up when travelling even in cooler weather put aside time to walk them in hand for 10 minutes after their journey and you may also need to hose or sponge them down at the end of their journey so take lots of water with you.
Conditions to watch out for in hot weather:
Suncream in hot weather isn’t just for us! Grey horses and horses with areas of pink skin on their face are particularly prone to getting sunburn and just like with people, the sun damage can affect their skin in the future. Test the suncream on a small area of skin to ensure there are no allergic reactions.
Sunburn usually manifests as areas of hair loss or skin flaking and reddening of the affected areas of skin. If your horse becomes sunburned it is best to either keep them in during sunny weather or cover up the sunburn. Using aqueous cream or an antiseptic cream from your vet on the lesions can speed up the healing.
Photosensitisation is very similar to sunburn however it can occur in not particularly strong sunlight. It can happen after your horse eats certain plants which affect how the skin responds to light, for instance buttercups, bog asphodel and St John’s Wort. If your horse has sunburn check around their field for these plants
The skin reactions appear like very extreme sunburn. And like sunburn keeping out of the sun and using mild, moisturising, antiseptic creams can help the skin heal faster.
When horses become overheated, they can become angry and agitated. Temperatures above 40’c are abnormal. If your horse has a high temperature and seems distressed after exercise or travel then contact your vet, your horse may have an infection or they could be struggling from heat stroke. Withhold food until your vet has examined your horse but try to cool them down with buckets of water or hosing them down.
Signs of heat stroke to watch out for:
- Profuse sweating
- Increased temperature, pulse and respiratory rates
- Lethargy and dullness
- A reluctance to work
- Loss of appetite
- Staggering and weakness
- Muscle tremors
Treatment of overheating:
- Move your horse into shade immediately
- Cold hosing of the whole body, focusing on the big muscle masses in the hindquarters. Do not put wet towels over them as that just traps the heat. It is best not to scrape off excess water and sweat, but to leave the water to evaporate.
- Gentle walking or stand in a breeze / under a fan to help cooling.
- Offer small amounts of cold water to drink (half a bucket, maximum 10l) every 30 minutes
Please call your vet if you are worried at all or have any questions.