SOME HORSES grazing summer pasture in Louisiana develop respiratory distress caused by an asthma-like condition, according to LSU AgCenter veterinarian Dr. Steve Nicholson.

“Unfortunately this is not an uncommon problem,” Nicholson said, adding, “This condition also is seen in horses exposed to dust from hay and straw bedding materials.”

Old-timers referred to the condition as “the heaves,” because of the labored breathing affected animals display, Nicholson said. But medically speaking, the correct term is chronic obstructive pulmonary disease or COPD, for short.

“Horses with COPD overreact to inhalation of irritants such as dust, pollens and especially molds and bacteria,” the veterinarian explained.

“Their airways become inflamed and thickened. Accumulation of excessive mucus and debris, combined with bronchoconstriction impair oxygen uptake, make breathing difficult.”

The veterinarian said affected horses usually do not have a fever but they do cough.

“Diagnosis is based on the history and clinical signs,” Nicholson explained, adding, “If there is any doubt about the diagnosis, veterinarians may use endoscopy to view the airways.

In another procedure, airway fluids collected by bronchiolar lavage can be examined microscopically for cell types present.”

Treatment with anti-inflammatory and bronchodilator drugs provides considerable relief for horses affected by COPD, according to Nicholson, who says these horses also should spend less time grazing summer forages than normal animals.

“Feeding a grain ration reduces the time they need to spend grazing,” he said, stressing, “Also keep in mind that hay should not be stored in the same air space in the barn where these horses are stalled.”

Nicholson urges horse owners to have their animals examined if respiratory distress is noticed.

“If an animal is diagnosed with COPD, it is important that the owner learn as much as possible about managing the disease,” he said.

For more general information on issues such as caring for livestock, visit the LSU AgCenter's Website at www.lsuagcenter.com.