A FAST Scan Could Save Your Pet’s Life After an Accident

dog ultrasound

Story at-a-glance -

  • FAST, or Focused Assessment with Sonography for Trauma, is an ultrasound technique being used increasingly by veterinarians for emergency situations
  • FAST scans can quickly assess areas of the body (typically the abdomen or thorax) for pockets of fluid
  • After trauma, these fluid pockets may be blood, which means the animal is suffering from internal bleeding and may need emergency surgery or other life-saving treatment

By Dr. Becker

It's a topic most pet owners would rather not think about, but if your pet ever becomes a trauma victim (is hit by a car, bit by another dog or severely injured in any way), a FAST scan could save her life.

FAST, or Focused Assessment with Sonography for Trauma, is an ultrasound technique being used increasingly by veterinarians for emergency situations. FAST scans have been used in human emergency rooms since the 1990s, and it's now standard care across the U.S. in trauma situations.

What does the FAST scan do? It's a type of ultrasound that can quickly assess areas of the body (typically the abdomen [AFAST] or thorax [TFAST]), the area of the body between the neck and abdomen) for pockets of fluid.

After trauma, these fluid pockets may be blood, which means the animal is suffering from internal bleeding. Veterinary clinics do not even need an ultrasound machine to perform FAST, as it can be performed with an ultrasound probe that hooks up to a laptop or smartphone.

And while it takes considerable training to be able to accurately read conventional ultrasound results, FAST scans can be quickly evaluated in less than five minutes with some basic training. In the midst of a veterinary emergency, every minute counts, which is why FAST scans can save lives.

FAST Scans Help Determine When Surgery Is Necessary

The use of FAST scans in dogs was first described in the Journal of the American Veterinary Medical Association (JAVMA) in 2004.1 Its use was evaluated in 100 dogs who had been involved in motor-vehicle accidents. The researchers concluded:2

"FAST is a simple and rapid technique that can be performed on dogs in an emergency setting to detect intra-abdominal free fluid and can be performed by veterinary clinicians with minimal previous ultrasonographic experience."

Since then, its use has grown, as has an abdominal fluid scoring (AFS) system often used alongside it.3 When used on the abdomen, the animal is assigned a number from 0 to 4. AFS 0 means the FAST scan was negative for fluid in all four quadrants assessed while an AFS 4 means fluid was found in every quadrant.

Guidelines suggest that a score of 3 or 4 requires surgery to stop the abdominal bleeding, although in some cases bleeding could be stopped using another advancement in care: a pressure bandage and hypotensive therapy.

Some Animals Can Avoid Surgery Following Trauma

A case report in The Coloradoan described the case of Toby, a 4-year-old terrier mix who was hit by a car. Along with a shattered back leg, a quick FAST scan detected fluid in his abdomen (with an AFS 3).

A tap of the fluid confirmed it was blood and surgery was considered, but veterinarians instead decided to try a pressure bandage and hypotensive therapy to get the bleeding under control. The Coloradoan reported:4

"An elastic abdominal wrap was applied to provide counter-pressure, and medications were given to keep Toby's blood pressure just high enough to provide adequate circulation, but not so high as to exacerbate the bleeding.

With the pressure of the bandage and relatively low blood pressure, clots could form on Toby's spleen and liver, the most likely sources of bleeding. By the next morning, Toby's FAST score was down to 2, and later that day his blood counts had returned to normal.

He was ready to have his leg fixed the next day, and a veterinary surgeon skillfully [put] the many pieces of his tibia back together again. The following morning, Toby was discharged from the hospital."

Other Uses for FAST Scans

If your pet is involved in an accident involving blunt trauma, get her to an emergency veterinary facility immediately. The veterinarian will perform a physical exam, but it can be difficult to detect hidden injuries like internal bleeding.

Some veterinary hospitals solve this issue by monitoring the animal for at least 24 hours, but waiting until related symptoms become obvious could be too late to help some animals. The use of a FAST scan to detect accumulating fluid is therefore a potentially life-saving tool in these situations.

If you find your pet in this situation, ask the veterinarian if a FAST scan can be done. In addition to trauma patients, FAST scans can be used for other medical issues. This includes:

  • Bleeding abdominal masses
  • Sudden and severe abdominal pain (acute abdomen)
  • Fluid accumulations from heart failure
  • To screen for any issues after abdominal surgery and see if the bladder is filling with urine
  • Collapse, shock, disorientation or weakness

As VMD Technology reported:5

" … [T]he 'T' in FAST has been used to represent 'Triage' and 'Tracking' as well as 'Trauma.' This highlights FAST's usefulness in non-traumatic cases such as acute abdomens, collapse, weakness, disorientation, shock-like emergencies and respiratory distress patients."

While FAST scans can't replace a thorough physical exam or more comprehensive ultrasound, when required, it represents a quick, easy-to-use tool that could save the life of your pet in an emergency.

In planning ahead for veterinary emergencies, it's a good idea to call the emergency veterinary hospitals on your list and find out if this technology is available in the event your pet, heaven forbid, needs it.