Horse Side Vet Guide ®

Equine Health Resource

Rapid Breathing, Flaring Nostrils at Rest (Not after Exercise)

Code Red - Call Your Vet Immediately, Even Outside Business Hours

Code Red - Call Your Vet Immediately, Even Outside Business Hours

    Breathing rate is regulated by the brainstem, which responds to the levels of CO2 and Oxygen present in the blood. Rapid breathing is the body’s attempt to increase gas exchange in the lungs, it is also a response to overheating, stress and pain.

    Rapid breathing that is not associated with recent exercise is commonly seen in horses suffering from severe disease processes including heaves Recurrent Airway Obstruction (RAO), allergic reaction (anaphylaxis), exhaustion or heat stroke. Horses in end-stage shock that is caused by any number of severe illnesses or injuries (major blood loss, pain, metabolic problems, or heart failure) may breathe or pant heavily.


    Horses exhibiting this sign may be experiencing a life-threatening crisis. Keep the horse quiet and calm and contact your vet immediately. Perform the Whole Horse Exam, paying particular attention rectal temperature, and to the presence or absence of excessive respiratory noise. this may give a clue as to whether there is an upper airway obstruction. Assess the horse’s gum color, which reflect tissue oxygenation status. Are they bluish, pink or red? Regardless, this is a veterinary emergency.


    Your vet uses history and physical exam findings to try to determine what is responsible for the rapid breathing.

    POSSIBLE TREATMENTS or TherapiesTo Lessen or Resolve the Sign

    Author: Doug Thal DVM Dipl. ABVP


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