Overview of Kidney Stones in Cats
Nephrolithiasis is the condition marked by the presence of renal calculi or kidney stones. One function of the urinary system is the removal of body wastes in liquid form. Some mineral wastes are only slightly soluble and may form crystals. If the transit time of crystal movement through the urinary system is prolonged, crystals may interact and grow into stones.
Causes of Kidney Stones in Cats
Several types of stones can affect cats and dogs. Each type of stone is often associated with its own specific cause. General causes include:
Overall, nephroliths are slightly more common in the male cat and are generally seen in the middle-aged animal, although can be seen in any age. There are different breed predilections for each type of calculi. In cats, nephroliths are seen most commonly in the domestic shorthair.
Urine retention and the formation of concentrated urine may predispose to calculi.
What to Watch For
Clinical signs depend on the exact location, size, shape and number of kidney stones. Affected individuals may have no clinical signs. Other signs such as painful urination or frequent urination may be seen in patients who have a concurrent lower urinary tract infection. Some patients may be extremely ill if they have associated kidney failure or severe infection.
Diagnosis of Nephrolithiasis (Kidney Stones) in Cats
Treatment of Nephrolithiasis (Kidney Stones) in Cats
If your pet is on a stone dissolving diet, complete compliance is necessary. NO snacks or other diets are permitted, as these may negate the beneficial effects of the special diet. Administer all medication and return for follow-up as directed by your veterinarian.
If your pet is being treated for nephrolithiasis and suddenly seems ill, contact your veterinarian at once.
Eliminating urinary tract infections may help prevent nephrolithiasis. Treating and controlling underlying disorders may help prevent recurrence of stones.
In-depth Information on Feline Nephrolithiasis
Nephrolithiasis is the condition characterized by the presence of nephroliths (also referred to as calculi or kidney stones) which are stones located within the kidney pelvis. Nephroliths have several potential causes, and a host of possible presentations are associated with their presence. Some factors may enhance the susceptibility to nephrolithiasis such as congenital abnormalities, metabolic disorders or disorders that promote urine retention, but no specific underlying disorder need exist.
Individuals with kidney stones may be have no clinical signs, although some patients may be quite ill, as the presence of stones can cause pain and lead to kidney failure, sepsis (infection throughout the bloodstream) and even death. Depending on the specific case, specific diagnostics and therapeutics are tailored to the individual.
Several diseases/disorders are similar to nephrolithiasis. These include:
Certain diagnostic tests must be performed to diagnose nephrolithiasis and exclude other disease processes that may cause similar symptoms. A complete history, description of clinical signs, and thorough physical examination are all an important part of obtaining a diagnosis of nephrolithiasis. In addition, the following tests are recommended:
Your veterinarian may recommend additional tests to exclude or diagnose concurrent conditions. These tests are not necessary in every case, but may be of benefit in certain individuals and are selected on a case-by-case basis. These include:
Animals with inactive nephroliths that are not causing any clinical signs may not require therapy. They should be monitored periodically by urinalysis, urine culture, radiographs and/or ultrasound. Although some inactive stones may remain inactive for the duration of the individual’s life, it is important to note that inactive stones may become active, causing severe clinical signs with very little warning. Equally important is choosing the most appropriate therapy for the patient who is having associated clinical signs. All recommendations by your veterinarian should be followed very closely, and any questions or concerns that arise during the treatment protocol should be addressed immediately.
Follow-up Care for Cats with Kidney Stones
If your pet is on a stone-dissolving diet, complete compliance is necessary. NO snacks or other diets are permitted, as they may negate the beneficial effects of the special diet. Administer all medication and return for follow-up as directed by your veterinarian.
The expected course and prognosis is highly variable, depending on the type, location, and size of stone, and the presence of secondary complications. If your pet is being treated for nephrolithiasis, and suddenly seems ill, contact your veterinarian at once.
Eliminating urinary tract infections may help prevent nephrolithiasis. Treating and controlling underlying disorders may help prevent recurrence of stones. Dietary modification is recommended in animals with a history of stones anywhere in the urinary system to help prevent recurrence.
Optimal treatment for your pet requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve.
General blood work may need to be reevaluated as recommended by your veterinarian. Abdominal X-rays or ultrasound (depending on the stone type) should be checked every several months at first, and 1 to 2 times yearly thereafter. Urinalysis and urine culture should be checked as well.