1. Respiratory infections: Coughing is a common symptom of respiratory infections such as equine influenza, equine rhinitis, and pneumonia. These infections can be caused by viruses, bacteria, or fungi.
2. Allergies: Horses can also cough due to allergies to environmental allergens like dust, pollen, or mold spores.
3. Parasites: Some types of parasites, such as lungworms, can cause coughing in horses.
4. Chronic obstructive pulmonary disease (COPD): COPD is a progressive lung disease that can cause chronic coughing.
5. Heart disease: Coughing can also be a sign of underlying heart conditions such as congestive heart failure.
6. Foreign bodies: Horses may cough if they have inhaled a foreign object, like a piece of hay or straw.
7. Laryngeal problems: Issues with the larynx, such as paralysis or inflammation, can also lead to coughing.
8. Exercise-induced pulmonary hemorrhage (EIPH): EIPH occurs when small blood vessels in the lungs rupture during intense exercise, causing coughing.
9. Other underlying medical conditions: Certain systemic diseases or conditions, including certain types of cancer and autoimmune disorders, can also cause coughing.
If you notice your horse coughing, it's important to have it evaluated by a veterinarian to determine the underlying cause and receive appropriate treatment.