As the old saying goes "you can lead a horse to water, but you can't make him drink." While this is true, simply drinking the water is not always enough to ensure your horse is properly hydrated.
WHAT IS DEHYDRATION?
When a horse loses over 5% of their body weight, it is considered dehydrated. After a 12% loss, your horse is considered to be severely dehydrated and needs to see a veterinarian and receive fluids immediately as this can be life-threatening.
WHEN DO HORSES GET DEHYDRATED?
Horses can become dehydrated if they have been overworked, have not been drinking enough, or if they have been sweating excessively due to heat, stress, or illness. Another cause for dehydration is a mineral imbalance, when a horse is lacking the minerals needed to absorb the water they drink, most of it just flushes through without being properly absorbed.
HOW CAN I TELL?
The most common way to check a horse for dehydration is to pinch the skin on their neck. A properly hydrated horse's skin will quickly flatten out to its original position whereas a dehydrated horse's skin will take much longer to smooth out. In older horses this may not be as reliable as horses, like people, lose some of their skin's elasticity.
Another test is to check that the horse's mouth is wet, and the gums are slick. If not, this is a very bad sign, particularly if they are blue or red. You can press on the gum and see how quickly they go from white to their normal pink color. It should be very quick, if not, your horse may be dehydrated.
Other warning signs are an elevated breathing rate and pulse that does not quickly recover after exercise or a horse that does not sweat after exercise when they usually would.
Some horses show dehydration signs earlier than others and so it is important to keep an eye on your horse if you notice any changes.
HOW CAN I FIX IT?
It is important to get your horse drinking. If they have not been drinking, try to find out why.
Is the water clean? Some horses can be very picky on how clean their water and water bucket are.
Is it cold? Horses do not like cold water as it can shock their system. This is a common cause of dehydration in the winter months, and if you are in an area where it is very cold, you should look at a heater for your water bucket.
You can also make an electrolyte solution for your horse by adding some sugar and salt to a bucket of water. This will encourage your horse to drink and is easily absorbed by their digestive system. This should be offered several times an hour until they are no longer thirsty.
With severe hydration, or in cases where your horse refuses to drink, a visit from the vet is needed. The veterinarian will likely want to run an intravenous line to hydrate your horse quickly. Often the horse will want to drink and recover fairly quickly although the vet will probably want to do a blood panel to find out what caused them to stop drinking in the first place.
Make sure that your horse always has access to fresh, clean water that is neither too cold nor too warm. Clean their water trough and water buckets daily to prevent slime build-up, more for horses that like to dunk their food.
You should also make sure that your horse has a mineral and salt block available at all times. This helps them absorb the water that they are drinking and increases their thirst encouraging them to drink more. It also ensures that they have the minerals that they need to keep their internal organs functioning properly.
For horses that do not use a block, you can buy vitamin and mineral additives to put in their grain. This will work the same way as the block and is much more controlled.