1. People joke about “bulking up for winter,” but for horses that live outside, increasing calories is a very real need as it takes more calories to keep warm. A high-quality hay is the foundation of any healthy diet, and increasing calories through increasing the hay ration rather than grain is a healthier option. Older horses that are unable to consume their calories from hay due to dental disease might need another calorie source such as corn oil. Please consult with your veterinarian about dietary management during the cold winter months.
2. Your horse needs abundant, fresh water, even when it is cold outside. Check several times daily to make sure that his water source is not frozen! There are numerous types of heating units, made specifically for this purpose, to ensure that your horse has fresh, unfrozen water available at all times.
3. Keeping your horse in a warm, tightly shut barn is not necessarily a good thing as a closed up barn increases your horse’s exposure to airborne dust and allergens. A well-ventilated barn, even if it means a drop of a few degrees, will keep the air fresher, and healthier for your horse. If your horse has a non-infectious respiratory disease such as Recurrent Airway Obstruction ("heaves") or Inflammatory Airway Disease, being inside the barn is a particularly unhealthy option, since exposure to the high levels of particles in the air can trigger a flare-up of respiratory signs. Invest in a warm, weatherproof blanket and leave a horse with airway disease turned out, with access to a run-in shed for shelter.
4. Some of our horses that live outside year-round have their blanket on all winter. While blanketing is necessary to keep your horse warm, that beneficial clothing can sometimes hide things lurking beneath. This can also be true of horses and ponies that are not blanketed but grow a very thick hair coat. Make sure to bring the horse in and remove the blanket at least once weekly so that you can check for any new lumps, bumps or changes in body condition. Remember that a long hair coat can hide a lot and you need to actually touch your horse to get an idea of his/her condition. A good grooming session will provide the opportunity to check the horse out thoroughly, and provide some valuable bonding time when the weather is not conducive to riding!
5. Keep in mind that blanket management can impact the growth of your horse’s coat. Blanketing a horse will encourage less growth of the hair coat, so if you are going to blanket, be consistent.

Dr. Harris is a lecturer in the Section of Emergency and Critical Care at Penn Vet New Bolton Center.