Bladder Stone

Chloe came into the office peeing blood and licking her vulva. X-rays show a bladder stone.

A rock-hard bladder stone forms from minerals in the urine when a bladder infection happens.

Chloe, a fluffy Poodle-terrier mix has been leaving dribbles of bloody urine here and there on the floors. Plus, she's constantly licking her vulva. She was bright, alert, and happy, but did stop and lick a lot. I was able to feel the hard bladder stone simply by squeezing my fingers together on the back half of her belly. Abi helped me collect a few cc's of urine to see what the problem was. Next, I ordered x-rays.

X-ray of Chloe's abdomen. This view was taken when she was lying on her right side with her hind legs pulled back. A normal abdominal radiograph does not have that oval body in a bladder; urine should be in there, not hard stones. The X-ray confirmed my suspicion of a bladder stone; they are easy to feel on abdominal palpation.

Chloe's urine was abnormal in color too; it was cloudy red, from the red blood cells and white blood cells. I spun the urine down to analyze the sediment, see what I found below:

Urine chemistry supported the infection diagnosis. The dipstick here revealed a change in blood, elevated pH, and Leukocyte esterase. The blood was from the infection and the stone jiggling around, the high pH was because the bacteria were changing the acidity of the urine, making it alkaline, prone to stone build-up. Finally, white cells called leukocytes were there trying to kill the bacteria, that's why the dipstick picked up the purple color on the last square.

The urine was cloudy red, so I already knew we had a problem. I spun it down in a centrifuge to pull all the cells to the bottom. After discarding the liquid, I had a sample I could check in the microscope. Sure enough, the turbidity was due to the high number of cells in the urine. Most of the cells were our good old neutrophils, general all-around good guy white blood cells, but a suspicious cell here and there concerned me. Worrying they could be cancer I examined them closer, deciding they were large cells present because of the stone. There are certain things we look for when we check for cancers, one of which is irregular cell size, which I didn't see. Neither did I see active nuclear material inside these purple giants, suggesting these unknown cells had none of the common cancer characteristics, so I was able to push cancer way down on the list of possibilities. I knew it wasn't cancer, but the stone had to come out.

The bladder was popped up out through the incision. This one is red and irritated, look at the prominent blood vessels. A normal bladder is not so inflamed.

Notice the thickness of the bladder wall. This is abnormal and is there because of the irritation and infection from the rocks.

There were two of these stones in Chloe's bladder.

What are the Signs of Bladder Stones in Dogs?

Bladder stones start out small but over time can grow in number and size. Dogs with bladder stones typically have some or all of the following symptoms:

-Urinary accidents -Frequent attempts to urinate without producing much urine -Straining to urinate -Discolored urine -Licking around the urinary opening

How are Bladder Stones Formed and Treated?

Bladder stones are a collection of minerals and other materials. Most bladder stones in dogs are made from struvite, others are calcium oxalate, urate, or cystine crystals.

The most common are the struvites, concretions of minerals that stay in the bladder instead of being peed out. When bacteria infect the urine they secrete bad stuff that changes the pH, causing normally acid urine to become alkaline. That's why the pH part of the dipstick test changed away from orange. This allows dissolved calcium and other ions to precipitate out, forming hard stones with an infection at its core.

Surgery will be necessary to get the stones out of the bladder. Smaller stones can be cured over time with long term antibiotic therapy and diets that keep the urine acidity correct formulated to make the dog produce more acidic urine than they would otherwise.

What’s the Best Way to Prevent Bladder Stones in Dogs?

Once the stones are gone, diet plays a significant role in preventing their return. Manufacturers have formulated special foods that deter the formation of struvite, calcium oxalate, urate, and cystine crystals. Encouraging water intake is also important since crystals are less likely to form in the dilute urine.

For this reason, many veterinarians recommend the canned versions of these foods over the dry. Because diets designed to prevent bladder stones have to be fed over the long term, they must be nutritionally balanced. But pay attention to the type of diet and stones you use; if urinary acidification is taken too far, calcium oxalate stones can be the result.