Dogs, like people, suffer from bladder stones. Veterinarians refer to these stones as urinary calculi. They form in any section of a dog̵7;s urinary tract, but they form most frequently in the bladder. Bladder stones occur in any dog breed, but they most frequently occur in smaller breeds. Many factors affect bladder stones. If left untreated, painful complications occur.
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Signs
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Dogs with bladder stones may exhibit some of the following symptoms: frequent urination, straining while urinating, licking genitals, bloody urine, pain or depression. Sharp mineral crystals scrape the bladder lining causing blood in the urine. Only small amounts of urine can be eliminated due to crystal blockage, thus dogs need to urinate frequently. Complete blockage leads to pain, bladder rupture and possibly death.
Formation
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Microscopic urinary crystals appear in the urine and stick together forming the bladder stones (uroliths). The stone̵7;s chemical components form calcium oxalate, ammonium urate, magnesium ammonium phosphate or other crystals types. Higher concentrations of these chemicals cause higher incidence of stone formation. As crystals accumulate, the stone enlarges and interferes with urination causing pain. Factors influencing crystal formation include; genetics, urine pH, diet, infections and confinement.
Genetics
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No specific cause is indicated as the reason for bladder stone occurrence. Genetic physiology predisposes some dogs to crystal formation, but predetermination is not possible. Different breeds of dogs are predisposed to different types of crystals. A study by Doreen M. Houstan proved oxalate stones appear often in Lhasa apsos, while urate stones appear commonly in dalmatians.
Urine pH/Diet
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Urine pH (acidity) and diet interrelate, because certain crystals form in acidic urine, while others form in alkaline urine. Diets high in magnesium, phosphorus or calcium affect the urine pH, increasing incidence of certain crystal types. Lowering those chemicals and increasing both protein and salt will neutralize pH, thus decreasing crystal incidence. Boosting salt increases water intake and amplifies urinary output. Increased output helps flush crystals out of the urinary system, preventing stone formation.
Bacteria/Confinement
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Lengthy confinement predisposes dogs to decreased water intake and infrequent urination. Lack of frequent urine flow enables bacteria to multiply within the urinary tract. Increased bacteria cause urine pH changes, which lead to increased stone formation and bladder infection. Some bacteria become trapped within the stone and slowly escape as it dissolves. Therefore, treatment to dissolve bladder stones must include antibiotics.
Treatment
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Veterinary diagnosis and treatment is necessary. Most bladder stones dissolve with permanent dietary change, but others may need surgical removal. Both long-term antibiotic therapy and follow-up urinalysis prevent further stone formation. A change in diet may take 14 weeks to dissolve the stones. X-rays aid visualization of the dissolution process. Increasing water intake assists the process and implementation includes canned food and continuous access to water.
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