Human and animal diabetics both use ketostix or ketodiastix. These are reagent indicator strips that test urine for only ketone (ketostix) or for both ketones and glucose (ketodiastix). These links show examples of Ketostix  and Ketodiastix .
These stix are available at any brick-and-mortar or Internet pharmacy that sells human diabetic supplies. Stix do expire, so check the unopened expiration date when you buy them and record the date you open them. Keep the bottle tightly closed when not in use; prolonged exposure to air can produce false negative urine ketone test results .
If the foil-wrapped Ketostix, rather than the ones in vials are purchased, you may find it less wasteful. After the bottle is opened, the remaining unused strips have only a 6 months' life. By using the foil-wrapped ones, you can extend the "life" of your purchase. The singly-wrapped ones can have a unopened expiration date of up to two years. You are then only using what you need when you need it, having the rest still sealed and potent until the indicated expiration date .
You should test your pet's urine for ketones for the reasons discussed at ketones. You may test your pet's urine for glucose because (1) you've been instructed to do so by the vet as a method of gauging regulation, (2) your pet is undiagnosed and you want to determine whether there is hyperglycemia, or (3) your cat is in remission and you want to determine whether there is hyperglycemia.
Urine Glucose Testing
Some reasons for preferring testing glucose levels by using blood over urine testing is that the urine used in testing may have been in the bladder for hours. Because of this, it may not be a reliable indicator of what systemic glucose levels are at the time of testing . What's seen when testing urine for glucose is an average of what the level of glucose has been over a period of about 5-8 hours (the time period from last urination) .
Urine testing  also makes it more difficult to determine whether any hyperglycemia noted is the result of a Somogyi rebound pattern or a true need for an increase in insulin dosage. Urine only tests positive for glucose when the renal threshold has been exceeded for a length of time .
There also must be some degree of glycosuria (glucose in urine) present in order
for a urine test to detect development of hypoglycemia .
Evaluating the results. The stix bottle has instructions and color charts to show you how the color on the stix will change given the level of ketones/glucose in the urine over 15 (ketones) or 30 (glucose) seconds. Be sure to read the colors at those time intervals because the colors will continue to darken and a later reading will be an incorrect result. Timing with a clock or watch second hand instead of counting is said to be more accurate .
- If you see a "trace" or more of ketones, see ketones .
In a diabetic, any urinary ketones above trace, or any increase in urinary ketone level, or trace urinary ketones plus some of the symptoms above. are cause to call an emergency vet immediately, at any hour of the day.
When testing urine for ketones, the sample needs to be as fresh as possible. Ketones evaporate quickly, so there's a chance of getting a false negative test result if you're testing older urine .
At low levels, ketones can be detected in the urine (ketonuria) before they are found in the blood (ketonemia/ketonaemia) .
Ketodiastix--measures urine glucose and ketones.
- The glucose portion of the stix measures your pet's glycosuria --that is, the glucose that has collected in your pet's bladder since s/he last urinated. If you see any color change in the glucose portion of the stix, that means that your pet has exceeded its renal threshhold since it last urinated. The darker the color, the higher your pet's BG level has been since its last urination. Note that positive urinary glucose results are not indicative of your pet's blood glucose level at the time it urinated. No meaningful conversion between urine glucose and blood glucose readings is possible.
Ketostix--measures urine ketones.
- If you are testing urine for glucose, the time you test likely affects results in this way: mid-day urine glucose tests would reflect the nadir of glucose in the system--this also represents the peak of the insulin. Morning urine glucose tests are frequently high. Seeing negative urine glucose test, especially repeated negative ones, can mean the pet is approaching hypoglycemia  .