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Dr. B.
Dr. B., Veterinarian
Category: Dog
Satisfied Customers: 1376
Experience:  I have over 20 years experience in small animal and emergency veterinary medicine
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how much calcium does my dog need

Resolved Question:

my 11-lb shi-tzu/bichon frise mix is experiencing "amorphous calcium phosphate" in his urine and is having trouble passing urine at times. he currently is at the vet's office with a catheter until something can be figured out. he has been getting a supplement that provides 300 mg of calcium daily. he eats a homemade diet of fish, sweet potatoes and potatoes mostly, as he has many food allergies. just want to find out if the calcium supplementation is too large for him and it is contributing to his urination problems
Submitted: 9 years ago.
Category: Dog
Expert:  Dr. B. replied 9 years ago.

HI laima rastkis -

The daily nutritional requirements of calcium for an adult dog is listed as 119 mg/ kg of body weight. For an 11 lb dog, that would calculate to approx 595 mg of calcium total, but nutrition can be much more complicated than this suggests as levels of some nutrients can affect absorption of other nutrients. The ratio of calcium to phosphorous is just as important as the the calcium level alone.

If you are going to feed a homemade diet, I would strongly encourage you to consult a veterinary nutritionist so you make sure you are meeting all your dog's nutritional needs while keeping everything in balance. Here are a website that lists the board-certified veterinary nutritionists:;jsessionid=yfiakzw6ih8

and here are two websites where veterinary nutritionists can help you formulate homemade diets specific to your pets needs via online consultation. There are charges for these services.

I hope this answers your questions. If so, please click Accept. If you need additional information, please let me know.

Customer: replied 9 years ago.
do you know anything about treating "amorphous calcium phosphate" in a dog's urine?
Expert:  Dr. B. replied 9 years ago.

HI laima -

Calcium phosphate crystals are pretty uncommon. Calcium phosphate crystals are most often associated with an increased calcium levels in the blood stream, so that is something that should be checked if that has not already been done.

If there are stones (not just crystals) present within the urinary tract, they will need to be removed surgically as there are not any diets that will dissolve these.

If the homemade diet that this dog has been on was not formulated by a nutritionist, there is probably a good chance that the diet may be a contributing factor here and getting him on a more balanced diet could help prevent additional crystals from forming in the future. Also, it would be a good idea to try to keep your dog's urine as dilute as possible as that makes it harder for crystals to form.

Let me know if you have additional questions.

Customer: replied 9 years ago.
Is it possible to flush the crystals out of his system and then work toward preventing future ones through diet and other, nonsurgical means?
Expert:  Dr. B. replied 9 years ago.
Yes, crystals can be flushed out of the lower urinary tract, but if there are any stones present, they may be too large to flush and then would require surgery.
Dr. B. and 2 other Dog Specialists are ready to help you
Customer: replied 9 years ago.
thanks for your help