Dogs (and cats) can get both kidney and bladder stones. Just as we can. The causes are much the same — minerals precipitate in the urine as microscopic crystals, the crystals then form small grains of sand-like material as they bond together, which with additional precipitation of minerals lead to the creation of stones. Stones can grow pretty large, up to 30+mm in diameter. But no matter the size, serious problems arise when stones interfere with urination, even blocking it altogether.
Bladder stones can be of different compositions but the most common is the struvite — formed of magnesium ammonium phosphate. Different types and compositions of stones demand different treatments and management through diet — completely different, so its important to know what type of stone a dog has. Problem is there’s no reliable way of knowing, not until a vet extracts and examines one. Until then, the vet needs to work from the urinary pH; the dog’s age, breed, and sex; type of crystals in the urine, if present; radiographic density (how the stones appear on x-ray); whether infection is present; and certain blood test abnormalities.
Having said this, the most common stones found in dogs are struvite. Research studies have repeatedly identified the highest percentage of such stones are to be found in mixed breeds (25%), Miniature Schnauzers (12%), Shih Tzus (9%), Bichons Frises (7%), Cocker Spaniels (5%) and Lhasa Apsos (4%). And then mostly in females between the ages of 4 and 8 years and prone to bladder infections.
As to what causes some dogs to have a predisposition to form these stones rather than others, no one seems to have a definitive answer. Researchers continue to explore risk factors such as breed, age, gender (anatomy), and genetic predisposition along with environmental and nutritional factors such as food types, water, exposure to certain drugs and living conditions.
But it is the elevated level of urinary pH that directly stimulates the formation of struvite crystals and thereafter, stones. So its important to remove or at least moderate foods that alkalise the urine. You really need to achieve a urinary pH of about 5.5–6.5. A pH of 7 is neutral, everything below this level is acid and above, alkaline. Dogs naturally have a slightly acidic urine but when pH rises above 7, there is an increased danger of struvite crystals.
What we do know is that dry pet food or kibble is dehydrating and causes an increase in urine concentration and a higher pH, contributing to crystal and stone formation. We also know that diets high in cereals and carbohydrates, typical of many kibble biscuits and tinned foods have a large alkalising effect. Whereas red meat has a very significant acidic impact, not only this, fresh raw red meat is about 60% water.
Dr Bruce Syme of Vets All Natural, says..’Diets that are too high in cereal levels will result in a more alkaline urine, which is typical of many dry foods and tinned foods. Commercial pet foods commonly contain significantly higher levels of non-meat ingredients, as red meat proteins are the most expensive ingredient used, and are generally kept to a minimum level for economic reasons — meat by-products, and white meats such as chicken, do not have the same acidifying effect as red meat’.
The renowned holistic vet, Dr Karen Becker, makes the same point, ‘when dogs and cats who are designed to eat meat are fed a grain-based diet or a starch-rich diet, the starch alkalises urine pH, which can lead to the development of struvite crystals and stones’.
What can you do about the presence of stones or to prevent their formation?
A urinary analysis is required to assess whether bacterial infection is also present in the bladder. If so, this needs to be treated first and separately, with antibiotics. Bacterial infection and stone formation seem to go hand in hand but stones can form without apparent infection.
Once you’ve worked through the possibility of bacterial infection, you can then manage the situation through diet. Given the formation of the most commonly found struvite stones, are exacerbated by a higher (more alkaline) urinary pH, you need to reduce urine pH by feeding a low-carb, grain-free, potato-free and preferably fresh, raw food diet for increased moisture content.
The other thing here is to ensure your dog is drinking — filtered water (not tap, too many chemicals) plus other liquids such as meat broth, goat kefir and goat yogurt. The key is to keep liquids flowing to help flush the bladder and to dilute the urine as much as possible to prevent further crystal formation. Alongside liquids, you’ll need to provide increased opportunities for your dog to pee — don’t encourage your dog to hold its urine for long periods (which they can do).
Adding a little (a teaspoon, maybe two) organic ACV (apple cider vinegar) to each meal will help control against future bladder infections. Iodine found in organic seaweed powder, will also help, helping flush the bladder. A glucosamine supplement could also be of value. It’s been suggested that glucosamine forms a mucus lining inside the urinary bladder, creating a barrier and protecting the bladder from the irritation caused by any crystals.
It’s a good idea to measure your dog’s urinary pH using pH strips, from a vet or chemist (they sell the same for humans). Just hold the strip in the flow of urine at least daily, record the pH value and repeat over a few weeks, to get an understanding of how your dog’s urinary pH is tracking. Remember, a constant pH above 6.5 is of concern.
If stones and crystals do not dissolve through management of diet and liquid intake, and they continue to grow, they will need to be removed surgically. As will any stones located in the urethra or the ureters (the tubes that connect the kidney to the bladder) — which are serious and very painful.
Diet management alone can dissolve cystals and stones in the bladder but it will take a few months at least, for this to happen.
- Feed a raw diet. Make sure you choose red meats (more acidic) that are moisture rich. Feed sardines at twice weekly, include the non-salt spring water (if from a tin). Add a whole raw egg every 2–3 days.
- For a while at least (3 months or so) moderate the vegetable content of any meal, vegetables, like carbohydrates, are alkalising and may add to the elevation of urinary pH.
- If as part of your existing raw diet, you are already adding Vets All Natural cereal mix (many folk do—for good reason), reduce to a ‘small’ desert spoon per meal, not more than 10% each meal. It’s carb based mix and whilst the carbs are ‘good carbs’ (of a low glycemic index), they are still carbs nonetheless.
- Supplement with goat kefir and goat yogurt — goat kefir as an occasional drink (every second day to start); and a desert spoon of goat yogurt with each meal.
- Natural Animal Solutions DigestivitePlus for its support of the gut, digestion, intestinal tract and a healthy liver. Mix into each meal, as directed.
- Natural Animal Solutions Organic Seaweed for its iodine content. Use every 2–3 days, as directed.
- Natural Animal Solutions High Potency Vitamin C, fantastic for elevating the acid content of your dog’s urine.
- Add desert spoon of extra virgin cold pressed coconut oil, from most organic/health stores.
- Feed a carrot after each meal; and an apple (minus pips) as a daily treat. Both good sources of fluid.
- You might like to blend a little veg (green and yellow) with the goat kefir and vitamin C powder (see above), as a smoothy — twice weekly. Lots of goodness and fluids.
- Occasional meal of warm bone broth (beef rather than chicken) — either make this yourself from meat bones (easy); or buy an organic premixed one; but watch the added ingredients (a little onion and garlic are fine).