The common clinical signs associated with heaves include a chronic cough and exercise intolerance. Horse often exhibit an increased respiratory rate, and a nasal discharge may be present. Wheezing may be audible, and over time, horses will develop a 'heave line' between the flank and thorax. Severely affected horses will suffer weight loss and appear unthrifty. Pollen, dust or molds result in allergic bronchitis that is similar to asthma in people.
Heaves is a management-related disease, so the treatment is to remove the cause.
For example, remove the horse from the stable and turn it out to pasture. Most horses will respond quickly to feed and bedding. Changing bedding to shavings or shredded paper will often be helpful. In severe cases, removal of bedding material and placing the horse on rubber mats may be necessary. Soaking the hay in water for up to five minutes will help remove some of the dust and spores.