Urinary obstructions in cats are a life-threatening issue that vets see and treat commonly. 

And while most vets have a system for caring for these unfortunate felines, it is exciting to learn about new technology that may provide value during the treatment of these critical patients.

One such development is fluoroscopy technology, which is now more accessible than ever to general practitioners. Here are three ways fluoroscopy may help while unblocking a cat… 

Confirming Placement of the Urinary Catheter

Depending on the type of indwelling catheter used, it may be of value to check the placement of the catheter on radiographs. 

This is especially true for red rubber catheters—which can double back on themselves or even tie into a knot if too much of the catheter is placed into the urinary bladder—or for any catheter long enough to cause additional trauma if passed so far that the tip contacts and irritates the bladder wall.

While traditional x-rays may be used for this purpose, fluoroscopy offers the advantage of being able to adjust the catheter placement in real time. That way, the catheter can be quickly adjusted prior to placing sutures.

Real-Time Contrast Studies of the Bladder and Urethra

Blocked cats with severely distended urinary bladders are at risk for bladder rupture—whether from the condition itself or from manipulation (pressure or cystocentesis) while the bladder is excessively full.

A large bladder rupture is often obvious since a full bladder will suddenly become difficult or impossible to palpate. However, a small tear or leak may be more difficult to detect.

A positive contrast cystourethrogram can help to identify small ruptures, by looking for contrast outside the borders of the urinary bladder on radiographs. 

While traditional radiographs can certainly be used for this purpose, fluoroscopy may prove useful because of the ability to see things moving in real time, and the ability to move the patient and quickly see the abdomen at multiple angles without taking a lot of x-ray shots. 

In addition to the bladder, this can be very useful for tracking the movement of contrast through the urethra (to identify obstructing materials, strictures, etc.), versus only seeing a couple of snapshots in time on traditional x-rays.

Since contrast media can be irritating to tissue that is already compromised, a vet must weigh the pros and cons of doing a contrast study right after unblocking a cat. But this procedure could also be useful after the cat has had time to heal, to ensure the bladder is intact before the urinary catheter is removed and the patient is sent home.

Evaluating for Uroliths and “Sludge” 

In cats, sludge, sand, or gritty material—which may be a combination of crystals, blood clots, mucus, etc.—can accumulate in the urinary bladder. And while less common than in dogs, uroliths are sometimes diagnosed in cats.

On radiographs, sludge may be confused with a bladder mass or even sometimes with uroliths. Fluoroscopy can help with characterizing this material inside the urinary bladder (and distinguishing it from a bladder mass) by seeing how it moves in real time, as the patient is moved. 

Additionally, a vet could use fluoroscopy to track the progress of flushing this material out of the bladder (or urethra) after relieving a blockage. 

Conclusion

For many years, traditional radiographs have been included as part of the workup for blocked cats, and a vet can provide excellent care to feline patients with current protocols.

However, as fluoroscopy technology continues to evolve and become more accessible to general practitioners, it’s exciting to see the ways in which this modality can make a vet’s job easier and provide more information for patient care.

Written by: Dr. Tammy Powell, DVM