Stones and crystals are a common problem in dogs and I am frequently asked how to treat these conditions when diagnosed during a veterinarian visit. There are a variety of stones and crystals that can affect our dogs, so my first question is ‘What type of stones or crystals is present?’ The answer to this question is important because each type of crystal or stone is addressed differently.
Struvites
Struvite crystals are common and typically caused by urinary tract infections. Bacteria in the urine causes alkaline urine (high pH) which creates the perfect environment for struvite crystals to develop. When struvite crystals are found in a urinalysis done at your veterinarian’s office, the next step is to have your veterinarian do a sterile urine culture and sensitivity test. This test is done in-house at the vet’s office. The urine is collected in a sterile manner and sent off to a lab so the bacteria can be grown and identified. This is important so the correct antibiotic can be prescribed to kill the specific bacteria that is present. The antibiotics prescribed are usually given for a month. Then ten days after the dog has been off the antibiotic, another culture is done to make sure the infection is gone. Once the infection is gone, the urine returns to a normal pH and the problem is resolved. However, it is important to keep alert to any future symptoms that show the UTI has returned. These symptoms may include frequent urination, blood seen in the urine, or pain upon urination. Always take your dog to your veterinarian should any of these symptoms occur.
Because Struvite crystals respond to bacteria in the urinary tract, diet changes for this problem are not helpful.
For more information on struvite crystals, please visit this website:
Calcium Oxalates
Calcium Oxalate stones are most common in dogs over five years old and are more frequently seen in male dogs. They are also seen more commonly in certain breeds. Some of these breeds are Miniature Schnauzers, Miniature Poodles, Yorkshire Terriers, Bison Frises, Lhasa Apsos and Shih Tzus. It is thought this may be because of a genetic condition that causes a lack of nephrocalcin, which inhibits calcium oxalates from developing. The symptoms include difficulty urinating, blood in the urine, inability to urinate in a steady flow or increased urination. With any of these symptoms, please have a complete check up on your dog by your veterinarian.
Certain health conditions and the use of certain medications can enhance the development of calcium oxalate stones. Steroids can aggravate a calcium oxalate former by creating more calcium excretion in the urine. Cushing’s disease may also lead to calcium oxalate stone formation, as the increased cortisol production causes calcium excretion. In addition to steroids, other medications to avoid for dogs prone to calcium oxalates include furosemide, also known as Lasix.
Unlike struvites, diet changes can be helpful for dogs prone to oxalates. The primary foods that contain oxalates are grains and vegetables. Since dog foods are primarily grains, feeding a homemade diet is best so you can monitor the ingredients and the quality of foods being fed. Foods to avoidinclude barley, corn, brown rice, wheat, soy, most beans, potatoes, sweet potatoes, spinach and nuts.
Foods that can be fed include all meats, dairy (no soy-based foods and no flavoring or sweeteners), eggs, and a variety of low-glycemic vegetables. There are several sources that assess the oxalate content of food, so be sure to compare several lists. Below are a couple of lists showing low oxalate vs. high oxalate foods:
A raw diet without vegetables, fruit or grains is ideal for a dog prone to calcium oxalate or struvite stones or crystals as oxalates are highest in grains and vegetables. High quality protein diets are more likely to discourage bacteria growth, which is the primary cause of struvite crystals and stones. A good homemade diet would include 65% to 75% animal protein and 25% to 35% low glycemic vegetables which would include vegetables such as Brussel sprouts, broccoli, cabbage, yellow squash and zucchini.
Approximate feeding amounts are 2% to 3% of the dog’s body weight daily. On average, a 100 pound dog would get 2 to 3 pounds of food daily (approximately 4 to 6 cups), a 50 pound dog would get 1 to 1 to 1-1/2 pounds daily (2 to 3 cups) and a 25 pound dog would get 8 ounces to 12 ounces daily (1 to 1 ½ cups). When you feed a homemade diet without raw meaty bones, you do need to add calcium to the diet at a rate of 900 mg of per one pound of food served. This can be done by adding 900 mg of calcium carbonate per pound of food served.
Calcium can be another issue for calcium oxalate formers. While it is uncertain whether or not calcium creates problems, it is know that calcium excretion in the urine can form crystals and stones. Therefore, it is suggested to avoid foods high in calcium. Additionally, steroids should be avoided as they can cause calcium excretion in the urine. You can add some yogurt or cottage cheese, but only as a small part of the diet, not as main ingredient. You will need to add calcium to diet, but use a calcium carbonate supplement WITHOUT vitamin D. Vitamin D increases the intake of calcium.
A sample diet for a 25 lb. dog for one day (divided into two meals) might be:
– 3/4 cup cooked hamburger
– 2 eggs
– 1 tablespoon yogurt
– 4 oz. steamed and mashed cauliflower
Another sample diet might be:
– 3/4 cup cooked chicken breast
– 4 oz. chicken heart
– 1 tablespoon cottage cheese
– 4 oz. white rice
While we tend to use the ingredients in these recipes that our dog enjoys, it is important to avoid getting ‘stuck in a rut’ where you use the same meats and carbohydrates over and over. Variety is very important. Be sure to mix up the ingredients and use at least four different proteins and a good variety of low-glycemic vegetables.
Good meat options include beef or ground beef, ground chicken, ground turkey or turkey heart, ground pork, lamb, and baked white fish. In addition to the vegetables listed above, you can also feed white cabbage, Bok Choy and canned pumpkin. Be sure to boil (not steam) all vegetables before serving. This is necessary for several reasons. Cooking the vegetables is thought to reduce some of the oxalate content as raw vegetables contain a higher oxalate values and dogs can’t digest raw vegetables!
Supplements
Supplements that are beneficial for dogs prone to oxalate crystals includeEPA fish oil capsules at one gel cap per ten pounds of body weight daily and a B complex vitamin. Omega 3 fatty acids are renal protective and B Vitamins are thought to help fight crystal development.
Additional Tips
Both struvite and calcium oxalates prevention require providing your dog lots of fresh water and a moist diet. Be sure to offer fresh water around the clock, give treats of beef or chicken broth, and allow your dog many opportunities to urinate throughout the day as holding urine causes an increased chance of crystal formation which can lead to stone formation. All of these practices help flush the crystals from the system and keep your dog hydrated.
In addition to beef or chicken broth treats, other good moist treats include baked liver, hard boiled eggs and jerky treats. It is best to avoid grain-laden dog treats if your dog is prone to calcium oxalates!
If your dog is prone to crystals and stones, it is important to continually monitor your dog’s health to insure your dog stays infection free and that stones are not developing.
