Bladder Stones: Now You See Them, Now You Don’t

March 4, 2015

The two x-rays seen below are from the same canine patient, taken one month apart. The one on the left shows two bladder stones. On the right you can see the stones are no longer present in the bladder. How did this magic happen? Surgery? Laser therapy? Antibiotics? Food? Magic wand?

canine bladder stones

Canine x-rays. Left image indicates 2 bladder stones. (Click to enlarge.)

Surgery?
Nope. Surgery may be the fastest and most common treatment for bladder stones, but for this lucky duck dog surgery was not necessary. Bladder surgery is performed under general anesthesia. The surgeon makes an incision in the abdomen near the back legs and finds the bladder just inside the body wall. Because the bladder is a hollow organ, it will collapse when the surgeon makes an incision in the bladder wall. Special sutures are placed in the bladder to hold it up and keep it open while the stones are scooped out of the bladder with a bladder stone spoon.

Bladder spoons

Bladder spoons (click to enlarge)

PCCL?
Huh? This acronym stands for per cutaneous cystolithotomy. Using laparoscopy equipment, a pinhole incision is made in the bladder. A small camera is threaded into the bladder and its magnifying properties are used to visualize the tiniest stones. Using this non-invasive method, stones are busted up using the laser and then easily removed.

Laser therapy?
Guess again. For dogs of the right size with not too many stones, non-invasive bladder stone removal is possible. Stones can be fragmented using a special laser which is passed up the urethra and into the bladder. Once the stones are broken into small enough pieces, they are either flushed out of the bladder or removed with a special stone-removing basket which is passed up the urethra and into the bladder to gather up the stone fragments.

Antibiotics?
Yes, but only in part. I can hear you saying, “Wait a minute, this makes no sense. Stones are hard chunks of mineral. Antibiotics treat bacterial infections, they do not dissolve stone.” But, this dog’s urinalysis showed an infection in addition to the stones. The infection played a role in the development of the stones and without treating the infection, the stones will not disappear.

Diet?
Stones form in the bladder as a sequel to infection and also because there are too many minerals in the urine. Drinking more water dilutes the minerals and helps dissolve the stones. Taking advantage of that information, a diet was formulated to promote water drinking in dogs fed the special stone dissolving diet. The diet is also low in magnesium and phosphorus, the building blocks of a type of bladder stone called struvite. This diet does not work in every type of bladder stone, only the struvite ones. Antibiotics are necessary since as the stone dissolves, it releases bacteria, and thus the dog needs antibiotics until the stones are completely gone. Antibiotics alone will not dissolve the stone and diet won’t work unless the infection is controlled, so the correct answer for the magical disappearance of the bladder stones in this dog is diet AND antibiotics.

Signs of bladder stones
Dogs with bladder stones urinate more frequently than is normal, have accidents in the house and blood in their urine. If you see any signs like this, be sure to have your dog evaluated immediately by your veterinarian. View a prior blog post on bladder stones to see diagnostic images of stones.


Why Your Veterinarian Goes Crazy for a Urine Sample from Your Pet

January 28, 2015

pet urine sampleWhile it is not unusual for a pet to have an accident in The Animal Medical Center waiting room or while standing on an examination table, my reaction to that accident may be considered unusual. As the embarrassed pet family is grabbing for a paper towel or a tissue to mop up, I blurt out “stop” so I can get a syringe to collect the urine for analysis in the laboratory.

18 Tests in One Tube
At The Animal Medical Center, a urinalysis tests 18 different parameters from just a teaspoon of urine. Some of the parameters are assessed visually, like color and clarity. A special dipstick measures six values simultaneously – especially important here are glucose and ketones – indicators of potential diabetes. The urine is spun in a centrifuge and the material that collects on the bottom of the test tube is specially stained and evaluated under the microscope. Finally, a drop or two of urine is placed on a refractometer, a device that measures the specific gravity and assesses how concentrated the urine is.

A Snapshot of Your Pet’s Health
The results from tests performed on that teaspoon of urine I have collected off the table or floor gives me a whole lot of information about your pet’s health. The finding of red and white blood cells and bacteria when the urine is evaluated under the microscope suggests a urinary tract infection. Observation of crystals in the urine is common and may not represent disease, but if your pet has bladder stones, the presence of crystals gives a hint as to the type of stones, and knowing the type of stone makes treatment more specific and successful. For example, the presence of ammonium biurate crystals in a dog with bladder stones suggests the presence of an abnormal liver blood vessel, and the presence of struvite crystals in a dog with a urinary tract infection and bladder stones suggests struvite stones. In addition to filtering the blood to remove waste products from the body, the kidneys help maintain the body’s water balance. Drink too much and they excrete the excess, drink too little and they hang on to every molecule of water they can. When the kidneys don’t work well, they lose the ability to dilute and concentrate the urine. Measurement of a urine specific gravity, part of a routine urine test, helps veterinarians assess the kidney’s ability to dilute and concentrate and is a partial measure of kidney health.

So much information from something you, the pet owner thought was just an accident. No wonder I am crazy about getting that urine sample from your pet.


Leaving No [Bladder] Stone Unturned

July 17, 2013

The veterinarians at The Animal Medical Center attended to several canine patients last week – Chompers, Maxie and Theo – all of whom were suffering from bladder stones, technically called cystic calculi. Bladder stones form when the urine contains excess amounts of a substance, usually a mineral, such as calcium or phosphate. The cause of the excess can be due to diet, abnormal metabolism, a genetic defect, or most commonly, a urinary tract infection.

X-rays can be used to find some bladder stones. Below, you can easily see the four stones in poor Chompers’ bladder. His stones were easily found, but that is not always the case. For example, dogs with stones resulting from an abnormal liver blood vessel, or from the a very specific kidney abnormality of Newfoundland dogs, stones require identification through ultrasound testing.

stones1

Chompers has four bladder stones

The second patient, Maxie the Maltese, had several stones identified on an ultrasound performed because she was having accidents in the house. A urine sample was submitted to the lab, which showed an infection. Treatment with antibiotics was given to control the infection, but additional treatment will be necessary to remove the stones.

stones2

Ultrasound image of Maxie’s stones

Theo, a one year old Yorkshire terrier came to The AMC’s ER for blood in his urine. Because abnormal liver blood vessels and bladder stones are common in Yorkies, his surgeon performed an abdominal CT scan to investigate. The scan confirmed a half inch diameter bladder stone and an abnormal liver blood vessel. Both the stone and the abnormal blood vessel were corrected during surgery.

The bright white circle is a bladder stone resulting from a liver abnormality.

The bright white circle is a bladder stone resulting from a liver abnormality

Rock removal
The traditional method of removing bladder stones requires surgery, which is a procedure many general veterinarians routinely perform. Once the bladder is accessed via a skin incision, the bladder is opened and a scoop is used to remove the stones. After closure of the incisions, an x-ray is taken to ensure all stones have been successfully removed.

These days, there are as many methods of stone removal as there are stones in some bladders. Non-surgical methods sound easy, but calculolytic (stone dissolving) diets work for certain stones, called struvite. Urohydropulsion flushes small stones out of the bladder, but will not work if the stones are too large. Another method of non-surgical stone removal is lithotripsy. Bladder stones are pulverized using lasers, allowing the fragments to pass through the urine.

Minimally invasive methods of stone removal can also be used. These procedures require an endoscope which enters the bladder after passing through a skin incision.

Signs your pet may have bladder stones:

  • Accidents in the house
  • Bloody urine
  • Staining to urinate

If you see any of these, have your pet evaluated by your veterinarian immediately, because bladder stones make your pet uncomfortable and there is a risk of a urinary blockage if the stones lodge in the urethra.

All the treatments described above are available at The Animal Medical Center, including the minimally invasive procedures such as lithotripsy. If you suspect your pet may have bladder stones, our veterinarians are on site 24/7 to diagnose and treat your pet.


Urine Dribbling: Plugging the Leaking Dog

December 14, 2011

Willa came to The AMC today. Her owner was worried she might have diabetes because the dog bed was smelly and soaked with urine the last couple of mornings. Dogs with diabetes (and cats too!) will drink and urinate excessively, often having accidents in the house. When I questioned Willa’s owner, the “accidents” only happened when the dog was sleeping and there was no increase in water consumption or urinations. A quick test of the urine the owner brought with her dog determined diabetes was not the problem.

Causes of Urine Dribbling
Simple and complex disorders can lead to urination abnormalities in dogs. Infections, bladder stones and hormone problems are common causes of urine leakage and can readily be identified with routine blood tests, analysis of urine and x-rays. The x-ray to the right shows a dog with four large stones in its bladder. In some cases, a special diet will dissolve bladder stones. In this case, surgical removal of the stones resolved the urine dribbling.

In Willa’s case, testing showed no urinary tract infection, no stones and no blood test abnormalities. Because she is an older spayed female dog, I thought she might have “urethral incompetence.” Large breed, older, spayed female dogs are at risk for developing this condition, which may be related to a lack of estrogen in spayed female dogs and occasionally neutered males.

Treatments for Urine Dribbling
Commonly it is treated with medications including drugs to tighten the urethra (known as α-blockers), such as phenylpropanolamine, ephedrine or pseudoephedrine, or with estrogen replacement therapy using diethylstilbestrol. Recently, the Food and Drug Administration approved estriol for use in dogs.

If your dog resists taking medications, specialists at The Animal Medical Center can inject collagen into the urethral wall using special noninvasive endoscopic equipment to help narrow the urethral lumen and prevent urine dribbling. For refractory cases, AMC specialists also use a hydraulic urethral occluder.

Willa quickly responded to treatment with estrogen and once again has a dry bed in the morning. With all these options available to plug the leak, no dog should have to suffer with a stinky, wet bed.

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This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit http://www.amcny.org. To make an appointment, please call 212.838.7053.


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