Bladder Stones

I still remember those words from the vet, "Truffle needs surgery." I took her to the vet for what I thought was a hairball blockage and left scheduling a surgery to remove bladder stones. I'd heard of stones, but had no idea what they were or how to treat them.

What Are Bladder Stones?

Bladder Stones (uroliths or cystic calculi) are rock-like deposits of minerals, crystals, organic material that develop in the urinary bladder. Bladder stones may be a large, single stone or a collection of stones that range in size from sand-like grains to gravel. The stones may be a mixture of both large and small stones.

Bladder stones removed from Truffle

Dr. Richard Goldstein, DVM (Cornell Feline Health Center) says "minerals are present naturally in a cat's body and stones form when the minerals exceed a certain threshold of concentration in the urinary system. When the concentration goes over that threshold, they start to form crystals, and the crystals accumulate and may grow into stone." Dr. Goldstein explains that they don't know why this process takes place, but veterinarians have found that stones tend to occur frequently in domesticated cats, especially those that are not very active, don't take in enough fluids, and don't urinate enough. There is some belief in the veterinary community that stress in the environment could cause bladder stones.

There are two types of bladder stones: Calcium Oxalate and Struvite. 

Calcium Oxalate stones (Minnesota Urolith Center) are the most common and difficult stone to prevent because the factors that are responsible for its formation are not completely understood. It's accepted that crystal growth and possibly initial crystal formation may be a reflection of urine supersaturation with calcium and oxalate. Cats who are fed a low-sodium or low-potassium diet or a diet formulated to maximize urine acidity are at increased risk for developing calcium oxalate stones. Some believe that neutered male Burmese, Persian, and Himalayan cats may be genetically predisposed to developing calcium oxalate stones. 

Struvite stones tend to form in sterile urine. The formation of struvite urolith formation in sterile urine is poorly understood; however, dietary and metabolic factors that result in alkaline urine and increased concentrations of magnesium, ammonium, and phosphate in the urine have been implicated (Grauer, 2019). Diets that are high in magnesium, phosphorus, calcium, sodium, chloride, and fiber, with moderate protein content have been associated with an increased risk to develop struvite stones. Struvite stones may be twice as likely to develop if urine pH is consistently elevated (6.5-6.9 versus 6.0-6.2).

How Are Bladder Stones Diagnosed

The most common symptoms of bladder stones are blood in the urine (hematuria) and straining to urinate (dysuria). Hematuria occurs because the stones rub against the bladder wall, irritating and damaging the tissues and causing bleeding. Dysuria may occur because of inflammation and swelling of the bladder walls or the urethra, from muscle spasms or due to a physical obstruction to urine flow caused by the presence of stones. Other possible symptoms may be frequent urination, genital licking, chronic urinary tract infections, urine spraying, and urinating in unusual places. Sometimes, cats exhibit no symptoms of bladder stones.

Dr. Boyette palpates Brulee's abdomen during an examination

If bladder stones are large enough, your veterinarian may be able to feel them through the cat's abdominal wall. However, most veterinarians tend to use radiographs (x-rays), ultrasound, urinalysis, and urine culture to diagnose bladder stones and help determine the underlying cause. If a cat is brought into the veterinary hospital who is experiencing abdominal pain or has recurrent episodes of hematura or straining, a veterinarian usually performs diagnostic imaging testing to help determine the cause. 

Treatment

There are multiple treatments if a veterinarian suspects stones in the bladder, however, the fastest solution is to perform a cystotomy and urolithotomy, or surgically open the bladder and remove the stones, especially if a diagnostic imaging test determined there were larger stones. The surgery is a routine procedure for removing stones and most cats make a speedy post-operative recovery. Stones are removed from the bladder and sent off for analysis to determine which type of stones were in the bladder to better determine appropriate treatment to prevent future stones.

A second option some veterinarians may use is to try and dissolve stones with special prescription diets. If you have a cat who has health issues which may cause complications for surgery, this is an option the veterinarian may consider. The disadvantages of treating the stones with a special diet are it's not successful for all types of stones, it's slow, and not all cats will eat the special diet.

Other less popular treatments are using a flushing procedure where the bladder is filled to induce urination, lithotripsy (breakdown of stones with shock waves), and waiting for the cat to naturally pass the stones.

Having plenty of water available

Prevention

After the stones have been removed and sent off for analysis, you'll have a better idea of to treat your feline to help avoid future stones in the bladder. You should have always have plenty of water available for your cat to drink, especially if she's had a history of bladder stones. It's not only important to have plenty of fresh water available, but you need to monitor your cat to make sure she is drinking the water. Some veterinarians prefer cats stay on a prescription diet, depending on the type of bladder stones that were present. Even if your cat is on a special diet, at least 50% should be wet food. High moisture foods are more effective because increased water consumption is associated with decreased urine concentrations of calculogenic minerals. It's important to help your cat exercise on a regular basis to help keep her system healthy. Keeping the litter box clean will encourage your cat to urinate more frequently. Since stress may be a contributing factor for bladder stones, it's important to keep your cat's environment as stress-free as possible.

Your vet may recommend a urinalysis (pH should be maintained between 6.5-8.0 and specific gravity should be less than 1.030) and urine culture several times throughout the year to test for crystals and/or infection. Some vets may perform an ultrasound or other type of medical imaging during annual wellness checkups.

Mom Paula and Truffle at follow-up visit to vet

Personal Experience

Truffle was taken to the veterinarian because I notice she was going to the litter box more frequently than usual and I noticed some loose stools. I thought she may be fighting a hairball because both cats had done a lot of shedding that month. However, one night, I noticed her going back and forth to the box every few minutes and I saw nothing in her box. I rushed her back to the veterinarian the next day and x-rays were taken. As I said at the beginning of the post, the "young" vet came into the room very excited, saying, "we know what the problem is and Truffle needs surgery." The surgery was schedule for the first part of the next week.

Truffle stayed at the veterinary hospital overnight after her surgery and was sent home in a MPS - Medical Pet Shirt® Cat to protect the incision and stitches. This "onesie" was a life-saver for both Truffle and me. It took her a couple of days to get accustomed to the shirt, but it was designed where she was able to use the litter box with no difficulty and it was comfortable and snug enough where she felt safe and didn't bother the stitches.

Truffle's bladder stones were determined to be struvite stones and the veterinarian recommended feeding her a prescription food.  There are three different brands (Purina, Hill's Prescription, and Royal Canin) of feline cat food developed for specifically for urinary issues and bladder stones. I tried all three brands in both the dry kibble and canned food with Truffle and she really didn't like any of them. Both Truffle and Brulee were already eating the Royal Canin Persian food, so I thought I'd stick with this brand. Truffle did prefer the Royal Canin SO kibble and canned food. She didn't like the pate canned food, but would tolerate the Royal Canin SO morsels in gravy. It was very difficult to feed two different diets to my two Persian cats because Truffle would smell the "regular" food Brulee was eating and abandon her prescription diet and push Brulee away from her food bowl. Many times, I'd feed Brulee in a separate room, but she didn't like that because it was different.

Unfortunately, Truffle developed an infection at her incision site. I had to leave her with the vet for four days because I was scheduled to be out of town at a Blog Paws conference. Truffle's infection healed under the watchful eyes of the veterinary staff at Cherokee Trail Veterinary Hospital. Dr. Boyette had me bringing her in the office every month for a urinalysis to check her pH levels. The pH levels continued to be high and her urine wasn't dilute enough. We kept Truffle on the prescription diet and I monitored her water intake. Eventually, 6 months after Truffle's surgery, her pH levels were within the normal range.

This past year, I began feeding Truffle a high-quality, high-protein wet food to go along with the prescription kibble. This way, both Truffle and Brulee can eat the same food and actually enjoy it. I'd noticed Truffle's coat becoming a little dull and I knew she needed more. I did share my decision with the veterinarian and he said we'd monitor her closely each year. During her most recent 6-month wellness checkup, another urinalysis and ultrasound were performed. Truffle's pH values are on the high-end of the normal range and her ultrasound didn't show evidence of stones. The vet still wants Truffle's pH levels more towards the middle of the normal range since she did have surgery. I have three different water fountains in my home and Truffle constantly drinks from all of them. In fact, as soon as she finishes eating anything (even treats), she goes to the water fountain and drinks.

I also try to keep my home as stress-free as possible for the health of both of my cats. I keep Feliway or Comfort-Zone infusers plugged into my home at all times. When I need to travel overnight, I have a pet sitter to come into my home and she is one that both girls like and are comfortable being around.

This will be a life-time commitment for me to monitor Truffle through her diet, water availability and consumption, and regular wellness checkups with the veterinarian.

References

Cornell Feline Health Center. 2019. Bladder and Kidney Stones. Cornell University College of Veterinary Medicine. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/bladder-and-kidney-stones

Grauer, Gregory F., DVM, MS. Feline Struvite & Calcium Oxalate Urolithiasis. Today's Veterinary Practice. https://todaysveterinarypractice.com/feline-struvite-calcium-oxalate-urolithiasis/ 

Osborne, Carl A., DVM, PhD; Albasan, Hasan, DVM, PhD; Lulich, Jody P, DVM, PhD; et. al. Feline Calcium Oxalate Uroliths. Minnesota Urolith Center, University of Minnesota.

Lulich, Jody P, DVM PhD and Osborne, Carl A., DVM, PhD. Feline Struvite Uroliths. Minnesota Urolith Center, University of Minnesota.

Ward, Ernest DVM. 2016. Bladder Stones in Cats. VCA Hospitals. https://vcahospitals.com/know-your-pet/bladder-stones-in-cats

WebMD Veterinary Reference from the ASPCA.  2019. Bladder Stones in Cats. Fetch by WebMD  https://pets.webmd.com/cats/bladder-stones-cats#1