One of the first calls an equine veterinarian makes when examining a sick horse is whether its in shock. That’s because treating shock is a priority.

Shock results from inadequate blood flow in the body. Because blood carries oxygen and nutrients to all of the body’s organs, shock can rapidly be fatal.

A number of situations can result in shock. Sometimes, the heart doesn’t pump normally. In other cases, blood flow is blocked by an enlarged organ or pregnancy. The most common type of shock in horses is caused by decreased blood volume — for example, when fluid leaves the circulation to pool in other parts of the body.

The initial treatment for shock is usually fluid therapy. That’s why veterinarians often start giving fluids to a horse even before they complete a full examination. As I said, shock takes first priority.