As a dedicated cat owner, you're always on the lookout for potential health risks that could affect your feline friend. One such often overlooked issue is the presence of crystals in cat urine - specifically struvite, calcium oxalate, and urate. Often unnoticed until it becomes a significant issue, these crystals can lead to discomfort, urinary tract infections, and even life-threatening blockages. In this article, we will review the causes, symptoms, and treatments associated with these urinary crystals in cats.
What are urinary crystals in cat urine?
Urinary crystals are small, microscopic mineral deposits that can be found in cat urine. They never occur in a normal situation and therefore are always a medical concern. Some cats do not show symptoms of urinary crystals, which can make detection difficult.
Generally speaking, crystals in cat urine will develop under the influence of several risk factors. These can include the pH of the urine, urine mineral concentration, obesity, highly concentrated urine, and genetics.
The most common urinary crystals in cat urine are struvite, calcium oxalate, and urate crystals.
Struvite crystals
Struvite crystals in cat urine are the most common type. Struvite crystals can form due to infection or sterile conditions. In dogs, infection-induced struvite crystals are more common, while sterile conditions tend to result in more occurrences of struvite crystals in cats.
Almost all cases of struvite crystals in cat urine are not caused by a urinary tract infection (UTI).
The exact reasons why some cats develop struvite crystals in their urine, which aren't caused by an infection, can be difficult to determine. There are certain factors that we think contribute to the development of struvite crystals in cat urine.
Cats who have urine that's more alkaline (opposite of acidic) seem to be more prone to this issue. Also, if your cat's diet is high in things like magnesium, phosphorus, calcium, and fiber, it might make these crystals more likely to form. The same goes if these elements are found in high levels in your cat's urine or if their urine is overly concentrated. Lastly, there appears to be a genetic link to the development of struvite crystals in cats.
Calcium oxalate crystals
Calcium oxalate crystals in cat urine are another common type of urinary crystal that affects cats. It's thought that these crystals tend to form in highly acidic (low pH) urine, or when a cat has high levels of calcium (hypercalcemia) and oxalates in their system.
It turns out that what your cat eats and how much can play a role in forming calcium oxalate crystals in their urine. Research has shown that cats with these crystals often have been eating diets that are lower in things like protein, fat, salt, calcium, phosphorus, water content, magnesium, potassium, and chloride. These are all important nutrients, but their balance can be tricky when it comes to urinary health.
Another important point to remember is that heavier cats or those carrying a few extra pounds seem to be more at risk for struvite crystals. It's another reason to keep a watchful eye on your kitty's waistline and ensure they're getting a balanced diet and plenty of playtime.
Urate crystals
The last type of crystalline deposit commonly found in cats is urate crystals. These crystals will form when there are excessive amounts of uric acid in the bloodstream and urine. The abundance of uric acid in the urine will eventually crystallize forming urate crystals.
Urate urinary crystals in cat urine can be associated with liver disease (e.g. portosystemic shunt), genetics, or less commonly, caused by urinary tract infections (UTI) with certain types of bacteria.
As liver disease is a risk factor for the development of urate crystals in cats, there will likely be other symptoms present. These could include being small in size, not growing properly, and having problems with their nervous (behavior changes, incoordination, seizures) and gastrointestinal systems (vomiting, diarrhea, weight loss, lack of appetite).
What are the symptoms of crystals in cat urine?
Urinary crystals can show up in our cats in different ways, and being able to spot these signs is part of our duty as caring cat owners. If we catch these symptoms early on, it can lead to quicker treatment and help prevent any serious issues from developing.
- Frequent Urination: If your cat is visiting the litter box more frequently than usual, it could be a sign of discomfort caused by urinary crystals.
- Straining to Urinate: Cats with urinary crystals may strain while trying to urinate. This can often be mistaken for constipation.
- Blood in Urine: Hematuria, or blood in the urine, is a common symptom of urinary crystals. The urine may appear pink or red.
- Painful Urination: Your cat might cry out while urinating, indicating pain. They may also lick their genital area excessively due to discomfort.
- Urinating Outside the Litter Box: If your usually well-trained cat starts urinating outside the litter box, it may be a sign of urinary crystals.
- Behavioral Changes: Cats are experts at hiding their discomfort. Therefore, any changes in behavior, such as decreased activity, increased irritability, or loss of appetite, could be a signal that your cat is not feeling well.
How are crystals in cats diagnosed?
The presence of crystals in cat urine can be detected by a simple urinalysis test (urinalysis). This involves collecting your cat's urine and analyzing it for the presence of any abnormal components, including crystals or other materials. The size, color, and concentration of these crystals can tell us a lot about their type and severity.
As crystals in cat urine can be the result of other medical issues, your veterinarian may also recommend other tests such as blood testing to help determine why your cat has crystals.
What are the treatments for crystals in cat urine?
The treatment for crystals in cat urine will vary depending on the type of crystal present and any underlying conditions. Regardless of the type of crystal present, appropriate water consumption is key as it promotes urine dilution.
Struvite crystals are often treated with dietary changes. The ideal diet should have less magnesium and phosphorus, urine acidifiers, and lower protein to reduce urea and promote urine dilution. Examples of such diets include Hill’s Prescription Diet c/d™, Purina Pro Plan Veterinary Diets UR Urinary St/Ox™, and Royal Canin® Veterinary Diet Urinary SO.
Calcium oxalate crystals can be managed with diet modifications although the ideal composition is not yet known. Studies have indicated that a diet that is high in moisture (above 75% water) and includes alkalinizing foods, potassium, sodium, and chloride can help to lower the risk of calcium oxalate urolith formation.
The same prescription diets used to treat struvite crystals in cats can be used with success in treating calcium oxalate crystals.
Potassium citrate is useful in the treatment and prevention of calcium oxalate uroliths as it inhibits the formation of calcium oxalate crystals. Additionally, it helps in increasing the pH value of the urine, making the urine more alkaline.
If hypercalcemia is the cause of calcium crystals, this will also need to be treated.
For urate crystals, dietary therapy can also be implemented. Dietary modification decreases the excretion of uric acid, increases urine volume through dilution, and alkalinizes the urine. Additionally, reduction in protein is also an important aspect as it reduces the intake of purines.
Unfortunately, there are no commercially available diets for cats. To lower purine intake, it's common to substitute high-purine foods like fish and organ meats with those that have lower purine content such as eggs, vegetable proteins, and dairy products.
It is important to recognize the symptoms of crystals in cat urine, as it can indicate a more serious underlying problem. The most common types of urinary crystals in cats are struvite, calcium oxalate, and urate crystals. If your cat shows signs such as frequent urination, straining to urinate, bloody urine, painful urination, and behavioral changes, you should take them to your veterinarian for an examination and urine test. Depending on what type of crystal is present, treatment may involve dietary modifications such as changing their diet or introducing supplements like potassium citrate. It's also essential that you promote urine dilution such as using a water fountain and/or feeding canned food. By following these tips and consulting with your veterinarian if necessary, you can help keep your kitty healthy and prevent further issues arising from urinary crystals.