Visiting Vet: Urinary stones

Sometimes hard to unlodge, and fast action is needed.

A shih tzu with a seemingly upset stomach turned out to have a urinary problem. — Adam Grabek

Early one morning, Balboa, a 5-year-old male shih tzu, was let outside to powder his nose. OK, dogs don’t powder their noses. Even people don’t really powder their noses anymore, but it seemed indelicate to begin a column with words like urinate and defecate. Veterinarians joke among themselves about the funny euphemisms pet owners use to describe their animals’ excretory functions. But I digress. Balboa went outside to powder his nose, then came inside and vomited. Over the course of the day, the little dog became progressively more lethargic, and vomited repeatedly. His owners thought he had an upset tummy and gave some Pepto Bismol, but as afternoon rolled around decided to call their veterinarian, who then referred them to me, as mine was the Island practice on call that day for emergencies. 

“He goes outside and strains, but nothing comes out,” his owner reported as I spoke with them on the phone. Owners often think their pups are constipated when their dogs squat and strain nonproductively. Most of the time, the pooch in question actually has diarrhea, not constipation, and is simply experiencing that crampy feeling one gets with a case of “the runs.” I hesitated. I could give them the standard over-the-phone advice for dogs with mild gastroenteritis. Withhold food and water. Give over-the-counter medications like Pepto Bismol. Once the vomiting stops, gradually reintroduce water, then bland food in small meals. “Like tea and toast for dogs,” I usually tell people. But it was after three o’clock. The owners were really concerned, and I would rather see them during office hours than risk having to interrupt my plans later that evening. I gave them directions to my office.

When they arrived, Balboa looked alert but subdued. His color, hydration, temperature, and heart rate were all normal, but as I palpated his belly, Balboa tensed his stomach and hunched over. I immediately felt a large, unexpected mass in his caudal abdomen. Oh, crap. Well, no. Not crap. Urine. Balboa’s urinary bladder was severely distended, the size of a grapefruit, and tight like an overinflated balloon. He wasn’t straining to defecate. He was straining to urinate. My suspicions were confirmed when we took him for a brief walk to see if he could relieve himself. He tried and tried. One tiny drop of bloody urine dripped into the collection cup. 

The urethra is a narrow tube that, in males, runs from the bladder down through the penis to transport urine out of the body. Urethral blockage is a very common condition in neutered male cats, but not seen that often in dogs. When it does occur, it is usually caused by a small “stone” that has formed in the bladder (often the result of bacterial infection or metabolic disorder), but then has moved into the urethra and gotten stuck. It’s like putting a cork in the neck of a bottle. Urine can’t come out, but the body keeps making more. The bladder distends. Urine backs up into the kidneys. All kinds of havoc then ensues. 

“Let’s get an x-ray,” I recommended, expecting to see just such a blockage. But when the film was developed, no obvious “stone” was visible. Well, sometimes these stones are radiolucent, meaning they don’t show up on radiographs. It was time to pass a urinary catheter and see if we could clear the passage. I introduced the long, thin, flexible tube into the end of the urethra, and slowly advanced it. In a normal male dog, it’s easy to get the tube to go all the way into the bladder, but in Balboa, my tube would not pass farther than the first few inches. Attaching a syringe to the end of the catheter, I tried flushing with a blast of saline. The idea is to relieve the obstruction by dislodging the stone, so it can either move down and out or, if not out, then to try to “retropulse” it back into the bladder. Then the dog could be treated with special diets that can slowly dissolve the stone over time. Or surgery could be scheduled to remove the bladder stone, but with less urgency.

But I could not get the catheter to pass. The next step was to decompress his bladder by cystocentesis, in other words, passing a needle through the abdominal wall into the bladder and drawing out the urine with a large syringe, thus reducing the pressure. Sometimes once this is done, it’s easier to retropulse the stone. Not this time. I could not get Balboa unblocked. I advised them to head immediately to Cape Cod Veterinary Specialists, where he could get aggressive diagnostics, intensive treatment, and emergency surgery if needed.

Balboa was diagnosed at CCVS with a number of small stones in several places in his urethra. Although they were eventually able to pass a urinary catheter, they were unable to get one of the stones to move (the same one I kept hitting), so Balboa went to surgery. Even the surgeon could not dislodge that particular stone, so in addition to looking inside Balboa’s bladder, he had to do a urethrostomy to remove it, i.e., an additional incision made directly into the urethra. 

As I write this, Balboa is still hospitalized, recovering slowly — not out of the woods, but his prognosis is fairly good. Tests will help determine why he developed these stones. Appropriate treatments will be implemented to minimize the risk of recurrence, but he will have to be monitored throughout his life. I think about how his owners misinterpreted his symptoms as an upset tummy. How I, too, made this assumption, almost suggesting they try home care for gastroenteritis overnight, a course of action that might have proved fatal. What a blessing we agreed he should be seen promptly that day, and that his family was able to invest the time and money to take him to the specialists. Here’s hoping Balboa will soon be able to powder his nose again (oops, I mean urinate) without any trouble.