Chest ultrasound and FAST examination

What it involves

The FAST examination (an abbreviation of the English “focused assessment”) is a simplified, quick ultrasound scan performed on a patient in an emergency, without shaving and without laying the animal on its back. Within minutes it answers questions on which life depends: is there blood in the abdomen, is there fluid or air in the chest, is the heart working inside a pericardial sac filled with fluid, is there oedema in the lungs.

A full chest ultrasound is done at a calmer pace, in a stabilised patient: we assess the pleura, the peripheral parts of the lungs, the mediastinum and the heart. Ultrasound cannot see through air, so it does not replace an X-ray of the lungs, but it shows fluid and masses adjacent to the chest wall very well and allows the chest to be punctured safely to collect that fluid.

We combine the examination with echocardiography when we suspect that the cause of breathlessness is the heart — all in the same place, without moving the patient.

When it is used

We perform FAST on admission of every patient after an injury (being hit by a vehicle, a fall, a bite) and in animals with sudden breathlessness, pale gums, collapse or an enlarged abdomen — even before an X-ray, because it is quicker and does not require painful positioning. During opening hours, call before you set off; we see patients without a referral.

Planned chest ultrasound: for pleural fluid seen on X-ray, masses of the chest wall or mediastinum, assessment of the diaphragm, and for puncture of the pleural cavity.

Indications: symptoms that should prompt a visit

• A dog has been hit by a vehicle or a cat has fallen from a height and is breathing fast, has pale gums or a tense abdomen.
• An animal has suddenly started to breathe with effort, or a cat is breathing with its mouth open.
• A dog has become weak, has fainted and has an enlarged abdomen that seems to slosh — bleeding from a splenic mass is suspected.
• A dog bitten in the chest area by a larger dog has wounds and rapid breathing.
• A cat with diagnosed heart disease has suddenly deteriorated.
• After a procedure or injury, an animal has suddenly become lethargic and is breathing shallowly.

Conditions for which we use it in particular

Diagnostics beforehand

In an emergency there is no time for preparation — FAST is the first examination, carried out at the same time as giving oxygen, placing an IV cannula and taking blood. The veterinarian who admits the patient decides the order: first whatever threatens life, then the rest.

Once the patient is stabilised, we complete the work-up with X-rays of the chest and abdomen, a blood count, biochemistry, blood gas analysis or a clotting test and, if needed, echocardiography. We examine fluid taken from the chest or abdomen in our on-site laboratory (cytology, parameters), which often explains the cause straight away.

How it proceeds

Aftercare

A patient after an injury or with breathlessness usually stays in the hospital for observation with oxygen, fluid therapy and pain management — the lead veterinarian decides the length of stay and overnight monitoring. We carry out a follow-up FAST and X-ray before discharge.

At home, monitor the resting breathing rate (in a dog and a cat it should be below 30–40 breaths per minute during sleep), the colour of the gums and the appetite. Call immediately if breathing speeds up, the gums become pale or the animal weakens — outside our opening hours, use the 24-hour animal hospitals named in the discharge notes.

Frequently asked questions