Identifying shock in animals

Shock is not just a psychological state after a trauma, but in the veterinary context refers to the body’s response to severe pathological processes occurring in the body.

In essence, it is the inability for fluids (and therefore oxygen) to be appropriately transported around the body due to a variety of processes, from low blood volume (e.g. dehydration, blood loss etc), heart issues, issues with blood volume distribution (can occur with sepsis, anaphylaxis etc) or less commonly an obstruction to blood flow (e.g. heart worm, gastric torsion etc).

Unfortunately, it also creates a vicious cycle in which the progression of shock sets off a series of pathways in the body which can in fact make the shock worse, and lower the blood pressure even more.

For this reason, shock can start off relatively mild and go unnoticed, then rapidly deteriorate into a potentially life-threatening emergency as the blood pressure drops dangerously low.

Initially, clinical exam might note a fast heart rate, a slow CRT and a pale colour – this is early-stage shock when an animal is compensating for the changes. If it progresses untreated the animal might move to ‘decompensating shock’, where the heart rate gets faster, the CRT becomes more prolonged, and the gums may progress to a muddy brown colour. If this remains untreated, the animal can progress to stage three shock which is usually irreversible and fatal.

The treatment is complicated and must be rapid, but usually involves fluid and oxygen (with the exception of some types of shock which fluids could worsen). For this reason, a trained veterinarian should always be sought as soon as possible when there is any risk of shock.

Any animal with a major clinical illness or injury should be considered potential for entering a state of medical shock, and this is one of the reasons why monitoring of vital signs is so important.