A "cold" in a horse is a catch-all term for an upper respiratory infection. The root of this infection could be viral, bacterial or fungal, and it is characterised by coughing, lethargy, disinterest in food, runny eyes, runny nose and depression. Complications, which occur in approximately 10% of all cases, according to My Horse, could include a viral infection of the heart, bacterial pneumonia or damage to the lungs. There are several ways to treat a horse's cold to ensure the animal gets well and back grazing the open fields.
Allow the horse to remain outdoors for a few hours if the weather is warm. If the weather is cold or rainy, keep the horse inside and warm with a horse blanket.
Pay attention to the horse's body temperature. If the horse becomes hot and feverish, cool him down by rubbing his body with a damp cloth. Have the horse wear a blanket if he is cold. Monitor the horse for these changes and treat accordingly.
Feed the horse some grass or moist bran mash or pellets that have been soaked for 20-to-30 minutes. According to My Horse, grass is an excellent source of moisture, vitamins E and C and antioxidants. These foods are also easy to consume and will not irritate the horse if it has a sore, scratchy throat.
Offer the horse a steady supply of water. According to My Horse, a horse that is on a grass diet should consume anywhere from 4-to-5 gallons of water a day. A sick horse will also be more inclined to drink water that is not ice cold.
Speak to the horse's veterinarian about the possible use of medications to treat the horse's cold. A vet may prescribe medications such as flunixin meglumine or phenylbutzone to treat the horse's fever or any aches and pains.
Avoid riding the horse or using it in any work capacity until its cough and runny nose are gone for at least one week.
Isolate the sick horse from any other animals to prevent the upper respiratory infection from spreading. Any instruments used on the horses, such as brushes and blankets, should be sterilised and cleaned between each use to prevent spreading the infection any further.
Avoid the use of cough and cold medicines that are intended for humans, especially over-the-counter antihistamines, as these could cause excitement in the horse, according to My Horse.