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Finding The Adren0al Glands On Ultrasound In Large Dogs

A thorough abdominal ultrasound includes evaluating the adrenal glands.

Common reasons to look at the adrenals include searching for signs of neoplasia, Cushing’s, or Addison’s disease. And even in animals where adrenal disease isn’t suspected, sometimes growths or other changes to the gland(s) are discovered incidentally.

Unfortunately, sometimes adrenals can play “hide and seek” and be tough to find. That’s true for any dog—but especially for large dogs with deep abdomens, since the abdomen may be too thick for the ultrasound waves to penetrate well.

Having a repeatable system for where to look can help. Here are some steps for finding those tiny glands inside of a big dog…

Perform an Abdominal Ultrasound in the Same Order Every Time

Just like reading an x-ray or performing a physical exam, a systemic approach helps ensure that nothing is missed.

Each veterinarian may have their own preference for how to go through a scan in a stepwise fashion. For example, some may scan cranially to caudally. Others may scan clockwise, or have some other system. Any system is fine, so long as it covers everything you need to see and is easy to repeat on each patient. So choose what works best for you.

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In addition to revealing unexpected abnormalities of the adrenal gland(s) sometimes, systemically examining the entire abdomen will also help a veterinarian gain experience. Then, when it’s time to locate the glands on a patient with suspected adrenal disease, you’ll have plenty of practice to fall back on and may feel less pressure.

Where to Find the LEFT Adrenal Gland

To narrow the search, first, find the left kidney by scanning the left dorsal mid-abdomen.

Next, narrow the search even further by finding the vascular landmarks: the aorta (in long view) and the left renal artery.

Look for the spot where the left renal artery branches off from the aorta. The left adrenal gland should be just cranial to this junction.

Where to Find the RIGHT Adrenal Gland

First, locate the right kidney by scanning the right cranial abdomen.

Next, locate the vascular landmarks: the caudal vena cava (in long view) and the cranial mesenteric artery.

Apply some pressure, which will cause compression of the caudal vena cava and allow better visualization of the adrenal gland. The gland is dorsolateral to the vena cava and just cranial to the cranial mesenteric artery.

A Few Tips

It may be tempting to use the kidneys as a primary landmark since the adrenal glands are located near each kidney. However, the kidneys may overshadow the small glands. So while the kidneys are a good starting point, it’s also important to use vascular landmarks.

Color Doppler can be a big help, too. It often makes it easier to find and view vascular landmarks.

Minimize the distance between the probe and the adrenal glands as much as possible. This can be done by moving the probe as needed, and by applying gentle pressure if the patient allows.

What to Include In the Medical Record

Be sure to describe any abnormalities. Additionally, rather than just noting ‘normal’ or ‘abnormal’, it’s good to provide specific details in case a comparison is needed in the future. Here are some things to note, even if the glands look normal…

Measure and record the size of each gland. Measurements are typically taken from the cranial to caudal pole, as well as a measurement of the thickness of each pole.

Note if the glands are hypoechoic to surrounding fat or if their appearance is different than expected.

Classic adrenal gland shape has been compared to a ‘peanut’, or sometimes an ‘arrowhead’ for the right adrenal. Note if the shape is as expected or if it’s abnormal.

If any abnormalities are noted, list the most likely rule-outs and a recommendation for follow-up/monitoring or further diagnostics if indicated.

With practice, locating the adrenal glands will become second nature. It may still be challenging on some patients, but having a repeatable system and gaining experience will help.