Note: The author has had no veterinary or medical training. She has merely documented her experience with her dog's health problems. Be sure to check with your veterinarian before acting on any information you see here.
Lulich and Osborne say "Most dogs who have formed calcium oxalate uroliths are likely to form them again." In one study 3% reformed in 3 months after surgery, 9% by 6 months, 36% by 1 year, and 48% by 2 years. That's pretty dismal.URINE COLOR
Randy Walker DVM says that if the pet is fed only Hill's U/D dog food there is less than 10% chance the stones will recur. If not followed strictly, there is greater than 80% chance they will return. So there is an easy solution unless your pet is like Amie - allergic to the U/D Diet (see Finding a Dog Diet that Works). Several people have emailed me that their dog has reformed calcium oxalate stones even though the dog has been fed u/d exclusively.
Since calcium oxalate stones can re-form, frequent monitoring is necessary, even if your dog is eating the U/D Diet.
See Amie's Care Log for an organized way to track and document a pet's health care.
Urine color is a good indicator of kidney functioning (another good reason to paper-train). Stones result when the urine becomes too concentrated and substances in urine crystallize into stones.
The first urine should be straw-colored or light yellow. If it is dark yellow or orange, the urine is being concentrated. The body is conserving fluids making the urine darker. Clear urine means it is too dilute and indicates renal failure. Clear urine during the day is OK.
Take your dog to the vet if you notice blood in the urine.
As of February 1998 Amie's urine color varies from pale yellow to clear. I haven't correlated changes to any other change, but will begin to pay closer attention. Tests in April, 1998 showed blood in the urine that I didn't detect through color.
There are several indicators that Amie isn't feeling well. One of the first is her urine pH. Urine pH is a measure of the pet's acidity or alkalinity.
Dr Larry Adams, who performed Amie's lithotripsy said the solubility of calcium crystalls isn't pH dependent. "Alkaline urine merely shows the medications are working." This seems contrary to what I have read - that maintaining a higher urine pH will prevent stones from forming. Now I'm really confused. Nevertheless I continue to check Amie's urine, because it has been an indication of problems in the past.
A low pH may reduce kidney stone inhibitors by decreasing citrate in the urine. I'd really like to know what that is!
Check the first morning's urination, as soon as it appears, and before the dog has eaten anything. A pH of 5.0 is normal but is so acid that calcium oxalate stones could form again. Therefore we have been advised to adjust her medications so her morning urine pH is kept between 7 and 7.5. One Internet source says a urine pH of 7.5 is difficult to achieve or sustain. If normal pH is about 5.0, what are the long-term effects of a higher pH?
Struvite stones form in an alkaline environment. Amie has struvite indications. What is the pH level at which struvite stones form?
You can get pH paper (red and blue litmus papers) from a craft house. Don't. Yes/no or acid/base litmus paper isn't much of a test. You want paper that is more accurate. (See Sources of pH Paper).
Lulich and Osborne recommend the following procedure for calcium oxalate testing.1. After 2-4 weeks following baseline testing (radiography, urinalysis, serum calcium concentration), evaluate urine sediment and verify diet compliance. Check for calcium oxalate crystals in the urine.
If there are crystals, treat with potassium citrate (see Urocit) and check again in 2-4 weeks. Otherwise check in 3 months.
2. If there were crystals at the last check-up, check for them again. If they are present, consider vitamin B6 supplements and follow-up in 2-4 weeks. If no crystals were found, check again in 3 months.
3. If crystals are still showing up in the next check-up consider hydrochlorothiazide and monitor for hypokalemia or hypercalcemia.
4. At the 3 month check-up. make sure the diet is being followed, do a complete urinalysis, serum calcium concentration and radiography.
If there are microscopic crystals, began again with the tests and compare to the baseline tests.
If there are macroscopic stones, remove them non surgically by voiding urohydropropulsion and catheter retrieval and analyze the stones. Begin again with testing and compare to the baseline tests.
The Urocit label recommended regular monitoring. Whether or not your pet is taking Urocit, itseems like a good idea to check on your pet's health. Make a schedule for regular blood and urine tests.
Make sure the dog is not taking antibiotics and has been off antibiotics for several days. Get a first of the day "clean catch" urine sample. This is pretty easy in Amie's case because she is paper trained. We cover her newspapers with plastic wrap. If your pet isn't paper trained, attach an aluminum pie pan to a broom stick for females or put a glass cup or jar in the loop of a wire hanger for males. The test requires only 1 - 2 teaspoons of liquid. Pour it into a clean, dry glass jar. Put in the refrigerator until the appointment - within 2 hours.
Screen for crystals and bacteria.
The UC Davis nutritionist recommends checking specific gravity of the urine. It should be around 1018 -1020. If it is OK you don't need to be concerned with increasing water consumption.
The Kidney Stones Handbook says there is a urinalysis you send from home which measures 13 factors. Call for more information about the Stone Risk Diagnostic Profile at 1 800 531-3333.
The Urocit flyer said to check for serum potassium, acid-base balance, other electrolyte levels, acidosis, urinary citrate, creatinine, complete blood count.
Check for serum calcium concentration. If there is hypercalcemia, find out what is causing it. If corrected, stone therapy my be unnecessary.
Look for increased blood urea nitrogen (BUN), creatinine, potassium, phosphate and decreased hematocrit. One source said a low protein diet can cause changes in BUN and creatinine levels - how?
Tests that show hypoalbuminemia, azotemia, proteinuria may indicate renal failure.
Weight loss with anemia is a symptom of renal failure.
Creatinine level indicates the concentration of urine. Normal is 0.5 - 1.5. Amie is considered to be still concentrating her urine with a creatinine level of 2.0 (high normal). By the time blood tests show elevated levels of creatinine, the dog has less than 25% kidney function. A failure to concentrate urine is a sign of kidney dysfunction. In humans there is a test for creatinine clearance, glomerular filter rate.
I read that there are dip sticks to test for nitrates, indicating an infection. My vet, Claudia, said that they test positive only if there is a significant infection and we'd know there was an infection before that.
Kidneys filter and remove waste materials from the blood. When there is kidney disease some wastes remain in the blood instead of being excreted in the urine. These wastes are toxic. When Amie's pH has been too high or low for a while or when she has an infection, she seems toxic - obnoxious, very barky and easily irritated.
Signs of stones include frequent urination (often in unusual places), bloody urine, dribbling urine, straining, weakness, depression, loss of appetite, pain. Get the flyer "Canine Urolithiasis" from Hill's or your vet.
When Amie is sick she sleeps a lot, doesn't want to be touched and is irritable. She looks at me strangely, almost pleadingly. She has a pitiful expression on her face. Her breath smells like fish. She trembles. She can feel hot and feverish. The number of urinations per day decreases.
As she gets sicker, her playfulness diminishes to zero. She won't go for a walk or jump on or off the couch. She will begin to eat her wet newspapers or any tissue or paper towel she can find. She also will begin urinating throughout the house. If I put down an old towel in the kitchen, she will prefer to go there rather than on the living room rug. She smells like urine. I have just found a source that connects dry, red smelly ears with kidney dysfunction.
Only under extreme illness, she will refuse to eat. Usually she eats three times a day, but she may skip a meal when she doesn't feel good.
About 6 months after Amie's second lithotripsy she began dribbling - continuing to urinate after she thinks she's finished. If lithotripsy removed the stones, leaving slight kidney damage, why is she getting worse?
Excessive water intake. Look for puffiness and water retention. Since Amie never has been much of a drinker and has stopped drinking, almost altogether, I guess we should be alarmed if she starts drinking a lot again. Is it possible that drinking after eating food laced with Urocit has burned her tongue or gave the water a bad taste?
Large amounts of dilute urine. Notice any change in quantity of urine and note its color. Dilute urine means the kidney is failing to concentrate (toxins are collecting in the bloodstream). Call the vet if it is cloudy or foul smelling (may be an infection). Call the vet if urination ceases. Since Amie has been eating digestive enzymes she has been urinating larger quantities and much more frequently. As of February 1998 her urine output varies from vast quantities to small amounts.
Vomiting. Note: Vomiting can be due to the Urocit. If the vomit has a clear, frothy liquid, it indicates a stomach irritant. Call the vet.
Weight loss. It is especially important to monitor if your dog doesn't weigh much. We weigh Amie every chance we can at the vet's since she only weighs 7.25 lbs.
Failure to thrive. I can't stand it when Amie can barely lift her head from her pillow. This definitely gets my attention.
In older animals look for early tooth loss, poor condition, malaise, poor appetite.
A Hill's Pet Food Company brochure on the kidneys lists the signs of kidney disease:1) loss of appetiteThe end is near when Amie collapses, faints, is confused, has seizures, or goes into shock. She will go into a coma before dying. I hope she will have some great drugs to send her on her way.
2) increased thirst
3) frequent urination or no urination
4) poor coat
5) depression and/or vomiting
6) symptoms may appear suddenly or develop slowly over time.
CAUSES OF KIDNEY STONES
Unfortunately removal of calcium oxalate stones rarely corrects the underlying cause. And discovering the cause may be eternally elusive or un-fixable.
Canine kidney stones are more common in some breeds than others such as Dalmatians, Lhasa apsos, Branford miniature schnauzers. Of 20 cats and dogs on which Dr Adams at Purdue has performed lithotripsy (as of January 1997), 90% of the dogs were small purebreds - schnauzer, Yorkie, Lhasa, shitzu. And Amie, the teacup purebred poodle, was number 21. In humans kidney stones tend to run in families. Check with your breeder about your pet's parents and siblings.
Diet and Nutritional Supplements (see Diet - Modifications for Calcium Oxalate Kidney Stones). A chemist from the University of Chicago found that glycoprotein coats crystals and prevents growth of calcium oxalate. The enzyme that makes glycoprotein either malfunctions or there is not enough to work. Diet can slow the rate of growth. Research continues to find ways to increase production of glycoprotein.
Hypercalcemia means the cause is due to high levels of calcium in the blood, probably due to diet.
Hypercalciuria is a metabolic disorder which causes too much calcium to be absorbed from food eaten and dumps the excess through the blood and kidneys into the urine. This is found in humans diagnosed with primary hyperparathyroidism. Other causes include toxic levels of Vitamin A or D, excessive dietary protein, sodium or calcium.
Hyperoxaluria may be caused by excessive oxalate, insufficient calcium in the diet, a pyridoxine deficiency, or vitamin C excesses. Vitamin C turns into oxalate when exposed to air.
Endocrine disorders such as overactive parathyroid glands, chronic dehydration, urinary tract obstruction, inflammatory and degnerative diseases, diabetes mellitus, gout, and recurring infections can lead to kidney stones. Bowel disease can raise calcium oxalate levels, promoting stone growth. An untreated urinary tract infection can lead to kidney stones.
Dare I say this again? Find out what type of stones your dog has before you attempt to treat it. If your dog has calcium oxalate stones, it probably has a tendency toward a low or normal urine pH.
Glucocorticoids such as Prednisone promote bone resorption and increase urine calcium excretion.
Furosemide or antacids can put some at risk for hyperacalciuria.
Loop diuretics promote sodium and calcium excretion. Not good.
High Blood Pressure
In humans high blood pressure is a risk factor for kidney stones. People with high blood pressure don't absorb calcium properly in the kidneys. I would guess that the same things that contribute to high blood pressure (salt and lack of exercise) should be avoided in dogs.
Lack of Exercise
Several sources said kidney stones can be due to a lack of exercise. HJ & E Ullman in their book, Poodles, recommend a daily walk of at least an hour. The guilt rises.
Amie is irrepressible when it comes to exercise. One "expert" told me to let her tell us when she needs to play, otherwise she will play by herself. In fact, she will kick the ball in order to chase it and will run laps around the house. She will insist we play ball with her, yet she is often not very eager to go for a walk.
Insecticides, solvents or other toxic substances can affect kidney function.
It's interesting that some sources have said that skin problems and ear infections are caused by kidney problems.
Did we cause Amie's kidney stones by not walking her an hour a day? It's hard to blame her stones on this when we have made so many other errors in diet trying to solve her allergy problem. My next pet will not be a purebred small dog.
We've had to consider what actions we are willing to take regarding her care. We will not subject Amie to painful treatments to keep her alive. My dad died of kidney failure as a result of an aneurysm. He had a few dialysis treatments and shortly succumbed. But before he went, he was miserable. Our wonderful vet Claudia Lewis has promised to advise us of when it's time to euthanize. We will not subject her to a kidney transplant, removal or dialysis. We want a pain free, happy, perky puppy.
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