The term "exercise intolerance" is often used in veterinary publications. Owners can recognise this as reduced ability to exercise, as demonstrated by a reluctance or refusal to go for a walk or run, or reduced ability to exercise with the onset of fatigue before the usual amount of exercise has been completed. Often the animal may just stop mid-exercise and be reluctant or refuse to continue. Owners may notice an increased respiratory rate (tachypnoea), difficulty breathing (dyspnoea). Sometimes animals will be so weak that they collapse during exercise. On examination of exposed mucous membranes such as the gums, they may appear to be blue (cyanosis) or very pale (pallor).
Last updated : October 2013