Cats are good at hiding illness and pain. So, for some feline patients, it’s hard to tell what’s behind a bout of vomiting. 

A few of the many possible causes include:

• Hairballs.

• Food sensitivities.

• Dietary indiscretion.

• Infections or parasites.

• Stress.

• Pain.

• GI foreign bodies.

• Inflammatory conditions.

• Internal issues such as kidney disease or hyperthyroidism.

• Cancer.

Is it serious?

Often, it’s obvious whether the patient needs aggressive treatment right away or just needs a little bit of supportive care and observation at home.

However, other times it’s more difficult to know for sure. Those are the cases that may stay on your mind, making you wonder if the vomiting will continue or even become more severe.

It’s especially nerve-wracking if the patient went home for observation, but you’re concerned they may get worse overnight.

Reaching a diagnosis

Depending on the patient’s signalment, history, and physical exam findings, you’ll recommend the appropriate diagnostic tests.

Bloodwork

Bloodwork is a key factor in determining overall health status, and in establishing a baseline to monitor the patient for improvement or worsening of their condition.

These labs may be especially valuable in senior cats who have lost weight, when kidney disease, hyperthyroidism, or other internal medicine issues may be what comes to mind as the most likely diagnosis.

Imaging with x-rays and ultrasound

For some patients—especially if the vomiting is severe, or if you feel something abnormal on abdominal palpation—imaging may be needed right away. For patients with milder signs, you may decide to hold off on imaging at the first visit, but recommend the client bring their cat back if symptoms don’t improve.

And even if an obvious abnormality is noted on bloodwork (such as elevated thyroid hormone), imaging is still a good idea to rule out concurrent conditions, and to establish a baseline to compare any changes that show up on future imaging tests.

Either way, when it comes to imaging, radiographs are a good place to start. 

Radiographs give you a good overview of what’s going on inside the abdomen. You can look for masses, abnormal-looking organs, constipation, bladder issues, pyometra, signs of a GI obstruction, and much more.

However, sometimes more information is needed. Often, x-rays and ultrasound work well together to give you the full picture.

Ultrasound gives you additional clues about soft tissue structures, including:

• Differentiating a mass (size, what the borders look like, texture, thickness, etc.) from surrounding normal soft tissues. Silhouetting may make this interpretation challenging on x-ray images.

• Viewing bladder stones that aren’t radiopaque.

• Looking at small structures that are hard to see on x-rays, such as the adrenal glands.

• Inflammation of the GI tract or other internal organs.

• Finding evidence of a GI obstruction when it’s not obvious on radiographs (or, ruling out an obstruction—which may help you worry less if you decide to send the patient home for monitoring).

The list goes on, but the point is, x-rays and ultrasound can complement each other to give you the information you need, which can help you confidently diagnosis the mysterious vomiting cat.

Additional tests

Sometimes additional tests—for example, biopsies and infectious disease testing—may be needed to reach a diagnosis.

However, bloodwork, x-rays, and ultrasound are a great place to start. And often, these modalities will need to be completed prior to other modalities such as surgically obtained biopsies.

Lifestyle changes and monitoring

If the vomiting is due to a factor such as stress or hairballs, this may require a simple lifestyle change like providing Feliway diffusers and adding mental enrichment at home, or changing to a special diet.

But even in these cases, it’s good to rule out other, treatable medical causes—so a medical workup with diagnostic tests may still be recommended.

Keeping the vomiting at bay

If you have a patient with a chronic condition, you may recommend repeating the bloodwork, x-rays, and ultrasound at regular intervals.

A wellness checkup package that includes testing may be a good option for many patients—especially seniors. The wellness tests can be offered at checkups before the patient ever becomes ill, which gives you a great baseline for comparison with future test results.

Even though cats may not like to show symptoms of illness until a disease has progressed, wellness bloodwork and imaging (x-rays and ultrasound) can help to catch abnormalities early on, when the chances for treatment are better.

Disclaimer: This article is for general informational purposes only, and not intended as a guide to the medical treatment of any specific animal.

Written by: Dr. Tammy Powell, DVM