Winter is a time of increased frequency of lower respiratory disease in horses, and it is not just because of the cold weather. The main reason for the high incidence of lung inflammation during the colder months of the year is actually due to an increase in the time that horses spend confined to stables.


Lung inflammation occurs in 50-80% of stabled horses and is responsible for two diseases: inflammatory airway disease (IAD) and heaves. IAD is a milder form of heaves with clinical signs observed mostly during exercise. Both diseases have many similarities to human asthma. IAD and heaves lead to cough, increased respiratory effort, and poor performance. They can also interfere with the quality of the horse's life. These diseases are not curable, but they can be prevented and controlled with good environmental management. Medications may also be recommended by your veterinarian if a horse does not respond to environmental management alone.

The primary respiratory irritants present in barns that contribute to inflammatory lung disease include dust, mold, ammonia (from horses' urine)
and endotoxin (the outer cell wall of certain types of bacteria). The amount of dust in most barns reaches a high concentration, ranging from 1.5 - 39 mg of particulate matter per cubic meter of air. It is worth noting that OSHA, the federal agency that regulates workplace safety and health, allows a maximum exposure limit of only 5 mg/cubic meter. Arenas with sandy footing contain about 60 mg of dust /cubic meter.  

Bedding is another important source of dust and endotoxin, with straw containing an average of 9 mg of dust /cubic meter and 2,300 mg of endotoxin /cubic meter . Better bedding alternatives include shavings (dust
particles 1.5 mg/cubic meter and endotoxin 500 mg/cubic meter) and cardboard bedding (0 mg dust /cubic meter). Hay is also a major source of dust, endotoxin, and even mold spores.  

The barn environment is harmful not only to horses' respiratory health, but also to the people that spend a significant amount of time in the stable. Research has shown that people that spent 10 or more hours per week in a horse barn were 9 times more likely to have symptoms of lower respiratory disease (especially asthma) compared to people that spent less time in barns.
Some simple management strategies that can significantly improve the air quality in barns include:

  • Using low dust bedding such as shavings or cardboard.
  • Feeding good quality, low dust hay with no mold. Horses that suffer from heaves should have their hay soaked or steamed. More severely affected horses may not tolerate being fed hay and will require an alternative forage (such as hay pellets, hay cubes, or complete feed).
  • Avoid storing hay or straw within the barn. They should ideally be stored in another building, or at least in a separate room.
  • Using low dust footing in the arena or watering it frequently. There are some polymers that can be added to the footing of the arena to retain water and decrease the need for frequent watering.
  • Improving ventilation of the barn by leaving windows and doors open.
  • If there is an indoor arena attached to the barn, keeping the door to the arena closed. This will help to keep the dust of the arena from gaining access to the barn.
  • Removing urine from stalls frequently (at least once a day, or more often if your horse spends prolonged times stabled).
  • Turning out horses at times of increased dust such as during feeding of hay, mucking out and sweeping.
  • Maximizing pasture turnout. Horses with heaves may require 24-hour turnout.
Following these suggestions will help to keep the lungs of you and your horse healthier.

GVEC How To Series:
 How To Give An Intramuscular (IM) Injection to your horse.
Sometimes you are left with medication from your vet that you have to give to your horse. Here are a few tips from Dr. Joan Ayers to keep you and your horse safe.   Presented by:  Joan Ayers, DVM, Kellie Donovan, LVT, and Dew Drop.  

January 19, 2016
7 - 9 PM

"Using Body Condition, Topline Scoring and Weight as Indicators for Your Horse's Overall Health: Focus  on the Hard Keeper"

Presented by  Amy Leibeck, DVM in conjunction with Joe Monroe, Cargill Equine Enterprise Team, and Patty Sheffer, Territory Representative-Nutrena Feeds

Spend an evening looking into how to measure your horse, evaluate your hay, and balance grain rations  in order to achieve better overall health in those troublesome horses that can't seem to maintain weight easily.

Dr. Leibeck is interested in collecting hay samples and horse data on at least five horses to use as examples at the short course.   If you have a hard keeper, please leave a phone or e-mail message for Dr. Leibeck at the  office so that she can follow up with you!  

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