Clinical Signs of Shock in MWDs

Dogs in shock are amazing in how stable they appear on initial presentation, due to compensatory mechanisms.

- MWDs in early (compensatory) shock may have tachycardia, tachypnea, alert mentation, rapid arterial pulses with a normal or increased pulse pressure, decreased capillary refill time (< 2 seconds), and normal or bright red mucous membranes. While this MWD seems normal, it is already in compensatory shock. Immediate treatment at this point may stop the progression of shock.
- As the early decompensatory phase of shock begins, tachycardia persists, pulse pressure and quality begins to drop or may be normal, capillary refill time becomes prolonged, mucous membranes appear pale or blanched, peripheral body temperature drops, and mental depression develops. Aggressive treatment must be provided to halt ongoing shock.
- As late decompensatory shock develops, the heart rate drops despite a decreased cardiac output, capillary refill time is very prolonged or absent, pulses are poor or absent, both peripheral and core temperature is very low, and marked mental depression (stupor) is present. Irreversible cellular injury may be present to such a severe degree that despite aggressive measures at this point, many patients will die.