In the harsh months of winter, it can be difficult for horses to remain properly hydrated. When water troughs freeze over and are often busted out at varying levels of frozen, it becomes all but impossible to keep track of how much your horse drinks.
A lack of hydration can lead to a myriad of issues, especially colic. Just like people, a horse's teeth are sensitive to cold things. When water is cold, and especially when it freezes, horses tend not to drink in order to avoid that painful sensation cold water causes as it rushes past teeth. Unfortunately, this leads to improper hydration in the hindgut and can often lead to impaction colic. Feeding electrolyte supplements can work for some horses, but not all. Hauling hot water is also an option, but a time-consuming and often inconvenient one.
One option, instead of feeding electrolytes or hauling hot water, is to buy a heated water trough or water heater. Those can range in price from $30 to upwards of $100, but that is a small price to pay when you can avoid a vet bill that could start at $300.