Other signs associated with bladder stones include:
• Vomiting and abdominal pain
• Muscle spasms
• Loss of appetite
• Swollen abdominal area
• Straining to urinate
• Painful and frequent urination
The two most common bladder stones are magnesium ammonium phosphate (known as struvite) and calcium oxalate (often just referred to as oxalate). Why some cats and dogs develop bladder stones and others do not remains one of the yet-to-be-solved mysteries in veterinary medicine. Certain breeds, such as Himalayans, Persians, miniature Schnauzers and Lhasa Apsos have been shown to be predisposed to forming bladder stones.
Treatment options to address these rock-like mineral deposits that rub against and tear the tissue of the bladder wall and cause bleeding include surgery, urohydropropulsion, laser lithotripsy and dietary management.
The surgical procedure — called a cystotomy — involves making an incision through the abdominal wall to remove the stones while the pet is under anesthesia. The stones are sent to a lab for analysis and the pet is placed on antibiotics and a special diet during his recovery. This is by far the most expensive treatment option.
When the stones are small enough to pass through the urethra, a veterinarian may opt to perform urohydropropulsion. While the pet is under anesthesia, a veterinarian will insert a urinary catheter, fill the bladder with sterile saline and flush the stones out the urethra by compressing the pet’s bladder.
Another non-surgical alternative is the laser lithotripsy. This minimally-invasive option breaks the stones into minute fragments without damaging the surrounding tissue. A laser fiber is passed through an endoscope with Holmium: YAG laser pulverizing the stones and removing them from the bladder while the dog is under general anesthesia.
A slow-but-steady treatment option is feeding the affected dog a therapeutic diet low in magnesium and protein. Slowly, the ingredients in these special diets dissolve the stones and are designed to reduce the risk of recurrent bladder stones. Owners are also encouraged to increase their pet's water consumption by adding water to kibble, serving canned food or providing flavored dilute broths.
“We are learning how to turn on or turn off defective genes or use medications to block off this defective gene,” says Carl Osborne, DVM, Ph.D., DACVIM, director of the Minnesota Urolith Center. Since opening its doors in 1981, this center has amassed the world’s largest database of more than 750,000 veterinary samples of bladder stones removed from the entire urinary tracts of dogs and cats.
Hydration Is Key
Dogs and cats with a history of bladder stones should be encouraged to drink an increased volume of water.
Arnold Plotnick, DVM, a veterinarian who operates Manhattan Cat Specialists clinic in New York City, shares these tips to get a cat to drink more water:
• Switch from the traditional water bowl to a fountain-type water bowl. Cats are often fascinated by flowing water, and will usually drink more water if the bowl contains “flowing” water.
• Put additional water bowls in unconventional places. Cats are naturally curious, and if they stumble upon an additional water bowl where they don’t expect it, such as in the corner of the bedroom, or on a ledge where they sleep or hang out, they’re likely to increase their water intake.
• Don’t just refill -- replace. When the water level in your cat’s bowl decreases, don’t just add more water to it. Dump out the old water, clean the bowl and replace it with fresh water, preferably chilled, from a bottle kept in the refrigerator, instead of from the faucet.
By Sarah Zumhofe