If your pooch has been diagnosed with struvite stones in his bladder, your vet might put him on a special diet to help dissolve these stones and prevent new ones. These special diets are only available through your vet and require careful monitoring.
Struvite stones form in the bladder if your pup's urine becomes very alkaline, usually due to a bacterial infection. The bacteria that cause such an infection produce an enzyme called urease, which breaks the urea in your pup's urine down into ammonia. Ammonia makes the urine alkaline and causes bladder inflammation, releasing proteins into the urine. The alkaline urine and proteins lead to the chemical reaction that produces struvite stones, composed of magnesium, ammonium and phosphate. Once formed, these stones can cause your pooch pain and potentially fatal blockages of the urethra. Only surgery, non-surgical techniques and dietary changes can help relieve your stone-ridden pup.
There are several veterinary diets on the market to both dissolve existing struvite stones and help prevent their formation in the first place. You can only purchase these diets through your veterinarian, who must carefully monitor your pooch's progress on them. Some of these diets are okay to feed to your dog indefinitely, while others are only designed for short-term feeding, usually no more than six months at a time, to dissolve existing stones.
How Do They Work?
Struvite-prevention diets contain very low amounts of protein, phosphate and magnesium to keep your pup's urine acidic. This balance of nutrients reduces the amount of urea that your pup's body produces. With little urea present in the urine, any urease coming from bacteria in the bladder won't be able to break it down into ammonia and the urine won't become alkaline. The diets also contain high amounts of sodium, to increase your pooch's thirst and encourage him to drink plenty of water to keep his urine dilute.
While your pooch is on his new veterinary diet, your vet will monitor his urinary pH, which should ideally fall below 6.5, according to VCA Animal Hospitals. She may also prescribe an antibiotic for your pup if he has any stones currently in the bladder. Until the stones dissolve completely, the antibiotic prevents any bacteria inside them from flourishing.
Switch your pooch over to his new food over a period of a week or so, to get him used to it. If he won't eat it or doesn't like it, your vet may need to give him a special acidifying medication for his urine instead. These medications aren't recommended for use with special diets because the urine could become too acidic. Very acidic urine can lead to the formation of calcium oxalate stones, a different type of bladder stone.
Considerations and Cautions
Struvite-prevention diets aren't appropriate for all pups because they have high amounts of fat and sodium. Such diets may not be appropriate for dogs prone to pancreatitis. The low-protein content makes them inappropriate for pregnant or nursing pups as well because protein is needed for growth. While these diets come in both canned and dry formulations, canned formulas have a lower fat content and higher percentage of water to encourage dilute urine.
- Mar Vista Animal Medical Center: Canine Struvite Bladder Stones
- VCA Animal Hospitals: Struvite Bladder Stones in Dogs
- The Merck Veterinary Manual: Canine Urolithiasis
- Dogster: How Can I Prevent Canine Struvite Stones?
- Urinary Stones in Small Animal Medicine; Albrecht Hesse and Reto Neiger
- 2ndchance.info: Struvite Bladder Stones in Your Dog
- Minnesota Urolith Center at the University of Minnesota: Canine Struvite Uroliths
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