If you have been reading up on feline bladder stones, you might have come across articles that say diet and water play an intrinsic role in preventing them altogether. Breed disposition is also a factor.
In addition, preventing cat bladder stones is specific to the type of stone present. Here we will discuss the basic types, their causes and management.
Struvite stones are noted to be of highest incidence in Himalayans, Persians, Oriental and Foreign Shorthair cats, Chartreux and Ragdolls, and cases may be recurrent. This is the most common of all feline bladder stones, comprising nearly 50 percent of all cases worldwide.
Struvites precipitate from an alkaline urine (pH 7.0 and above), either as a result of alkaline diet, urine stasis or UTI-causing bacteria which increase urine pH. When the urine pH is increased, the risk of bacterial growth also increases. It would be advisable to do a urine culture in such cases, and give antibacterial remedies whenever an infection is discovered.
Management is therefore geared towards making the urine more acidic. Diet should have low protein content to decrease ammonium. Minerals that encourage struvite build-up like magnesium and phosphorus must be eliminated.
Sodium also helps in acidifying the urine and increasing thirst drive, thus encouraging urination to flush out such feline bladder stones. Otherwise, surgery may be done.
- Calcium Oxalate
This is the next most common type, comprising about 30 to 50 percent of all cases. Persians, Himalayans, Ragdolls, Siamese and Burmese cats seem to be more prone, especially in neutered males ages 5 and up. Cats with Vitamin B deficiency are also prone to these stones.
Contrary to struvites, these tend to accumulate when urine is acidic, so affected cats rarely have infections (Acidic urine is a harsh environment for bacteria to thrive on).
The blood calcium also rises so providing a diet that contains just enough calcium and magnesium is important in preventing cat bladder stones of this type. Diet should be low in protein, sodium and calcium. Milk and dairy, spinach, parsley and table salt must be eliminated as they can increase calcium.
Avoid acidic supplements like cranberry, Vitamin C and D, as well as Cortisone since it increases calcium levels. It is also vital to create more diluted urine by providing lots of water and non-acidifying canned food.
Unfortunately, elimination via dietary correction is not possible. Surgical removal via cystotomy, or an incision on the bladder is the preferred treatment method, although cystoscopy, which is less invasive, is possible if the cat is female and the stone is small enough to pass through the device.
If the urine is too acidic (below pH 6.5), potassium citrate is given to prevent stones from forming and to balance out the pH.
Since the recurrence rate is extremely high, quarterly to bi-yearly urinalysis and cultures are a key to preventing cat bladder stones of this nature.
- Compound or Mixed Uroliths
As the name suggests, compound urolith is a combination of types: an inner nucleus with a smaller outer layer of another mineral. Majority have an inner struvite core surrounded by calcium phosphate, and thus often present with UTIs. Antibiotics may be prescribed.
Because conflicts in treating the inner core and the outer core exist (i.e. treating the other may promote the formation of another outer mineral), vets advise surgical removal. From then preventive medical or homeopathic measures can proceed safely.
- Urate Stones
Like calcium oxalate stones, these are often seen in acidic urine and come as a result of uric acid build-up. Males – particularly Siamese and Egyptian Mau cats – are affected more frequently due to the mode by which protein metabolism occurs in their liver, which leads to the proliferation of uric acid. Cats that suffer from congenital liver shunts also seem to be predisposed.
Feline bladder stones of this type tend to be small and are commonly found in the bladder, which may cause urethral blockage.
A low purine diet (less meat and beef) is desirable when decreasing urine acidity. Surgery may be recommended especially when there is urethral blockage or a portosystemic shunt. Otherwise, stone-dissolving drugs and homeopathic remedies are given. Allopurinol is also prescribed to reduce uric acid.
- Ammonium Urate
These are typical of cats who have portosystemic shunts due to faulty ammonia conversion to urea that causes uric acid build-up in the blood and the urine. The combination of ammonia and uric acid creates ammonium urate stones.
Management of this type is similar to that of urate stones. High-protein diet is avoided, and allopurinol is given, sometimes with potassium citrate.
From what we see, dietary management plays a huge role in managing and preventing cat bladder stones, whatever the type is. Once your cat has stones, treatment can get tricky so it’s always best to act ahead. Give a well-balanced diet and plenty of water. You may also try all-natural homeopathic supplements like berberis and belladonna, which are both effective against feline bladder stones, and can even be prepared at home.