The only normal level when using urine test strips is "negative". Urine glucose testing is based on the fact that once the amount of glucose in the blood exceeds the renal threshold of 180 mg/dL, the kidneys can no longer process any more blood glucose and it spills into the urine. A dog's normal blood sugar is 70-90 mg/dL. Once it gets over 180, it passes into the urine, and can be measured by the urine strips.
When discussing results on a urine glucose test strip, it's important to always mention what brand you are using, as different brands use different measurement systems, and a "1" could be the highest glucose level on one brand, and the lowest on another.
An example of results from one type of test strip is Diastix. Their scale is as follows:
% Negative 1/10 1/4 1/2 1 2
(mg/dL) Negative 100 250 500 1000 2000 or more
Negative is the best result, then 100, and so on.
One of the negative aspects of urine testing is that it can't tell you when blood sugar has dropped too low. When you are treating an animal for diabetes, sometimes the blood sugar level can drop to dangerously low levels, and this won't show up on a urine test.
A diet will certainly make a change in diabetes, and in fact if your dog has diabetes your vet will put your dog on a special diet. If your dog is overweight, your vet will want him to lose weight. Your dog may need to eat a special diet, and eat smaller meals more often to help keep his blood sugar constant.
If your dog has not seen a vet, and is testing positive on urine test strips, or has other symptoms of diabetes, you should see a vet about insulin injections, diet changes, and exercise for your dog.
Here is a link to more information about diabetes in dogs:
http://www.cah.com/dr_library/diabetesdogs.html
Here is a link to more information about urine glucose testing:
http://www.petdiabetes.org/urine.html
Let me know if I can clarify anything or answer any more questions.
