Urine testing stix

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.

Testing reasons

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.

Reading Results

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.

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.

Medications & Urine Test Results

Antibiotic/Sulfa drug name	Effects
cephalexin, Keflex Cephorum (UK),Rilexine Cefixime/Suprax Cefotixin/Mefoxin Cefpodoxime Proxetil/SimplicefCefotaxime/Claforan other cephalosporin antibiotics enrofloxacin Baytril	less than accurate (false negatives & positives) urine glucose test results
Gantrisin, Septra Bactrim, Albon Chanoprim (UK) Duphatrim (UK) Tribrissen (UK) Trinacol (UK) more names at link	can alter urine glucose test results
Chloramphenichol Chloromycetin	can produce false urine glucose test results.
Tetracycline Helidac,Sumycin Doxycycline Doryx, Doxy 100 Monodox, Vibramycin Vibra-Tabs, Ronaxan (UK) Doxyseptin (UK)	false urine glucose test results
Penicillin and its derivatives ampicillin carbenicillin ticarcillin penicillin G other names at links	can produce false positive urine glucose test results.

Possible False Urine Glucose Test Results
Acetaminophen (brand names) Tylenol	Common use: Pain reliever.
Aspirin	Common use: Pain reliever. False positives possible (With urine test brand name Clinitest.) False negatives possible (With urine test brand names Clinistix or TesTape.)
Salicylates Pepto-Bismol, etc.	Common use: Diarrhea. False positives possible (With urine test brand name Clinitest.) False negatives possible (With urine test brand names Clinistix or TesTape.)
Phenazopyridine Pyridium, Geridium, Pyridiate, or Urogesic	Common use: Urinary tract infections. False positives possible (With urine test brand name TesTape.) Delayed reactions possible (With urine test brand names Clinistix or TesTape.)

Possible False Negative Urine Glucose Test Results
Diazepam (brand names) Valium	Common uses: Seizures, anxiety, muscle relaxant, appetite stimulant. (With urine tests brand names Diastix and Clinistix.)

Possible False Urine Ketone Test Results
Valproic Acid (brand names) Depakene, Depakote, Divalproex Sodium	Positive. Common use: Treatment of epilepsy.
Cefixime/Suprax	Positive with nitroprusside-based urine testing. Common use: Antibiotic.
Levadopa Metabolites	Positive with high concentrations.
Tricyclic Ring Compounds	Positive. Common use: Treatment of depression.
Captopril other drugs with free sulfhydryl groups	Positive. Captopril Common use: Hypertension (high blood pressure), various heart conditions, preserving kidney function in diabetic nephropathy.
Phenazopyridine Pyridium, Geridium, Pyridiate, or Urogesic.	Positive. Common use: Urinary tract infections.

Vitamin C Supplements
Possible False Test Results
Blood Chemistry	Decreased blood glucose and cholesterol test levels.
Urine Testing	False high urine glucose test results (With urine test brand name Clinitest).
Urine Testing	False negative urine glucose test results (With urine test brand name Clinistix).
Urine Testing	False negative urine glucose test results With other urine test brand name strips.
Urine Testing	False negative urine ketone test results

If your pet is taking any type of vitamin supplements, it should be noted on his or her medical records. Knowing that he/she is using them means being able to factor them into interpretations of test results.

False Readings from other causes

Possible False Urine Glucose Test Results-Other Reasons
Moderate Ketones	Negative if glucose is only slightly elevated.
Increased Urine Specific Gravity	Negative.
Decreased Temperature	Negative-refrigerated samples.
Very Concentrated Urine	Negative.
Expired Test Strips	Negative.
Contaminated Sample	Positive with oxidant contamination such as bleach or hydrogen peroxide.
Feline Urinary Obstruction	Positive-pseudoglucose.

Possible False Urine Ketone Test Results-Other Reasons
Pigmented Urine	Positive-Any other color except yellow or clear. May be the result of other disease processes.
Dehydration	Positive- lack of fluids can concentrate ketones
Old Urine Sample	Negative-ketones can evaporate rapidly.

Getting samples

How to catch urine. Some people place the stix under their pet's stream when s/he is urinating. Others catch urine in a dedicated spoon, ladle, or other collection device and dip the stix into the urine. Sometimes, catching urine from a cat requires stalking it. This can be a challenge in the UK where many cats are allowed outdoors to relieve themselves. Still others confine the cat to a small space (a bathroom) with an empty or almost empty litter box covered with plastic wrap that will catch the urine. Intervet has Internet pages with some ideas for performing urine tests on cats and dogs. More tips on collecting uring samples for dogs.

Further Reading

• Understanding Feline Diabetes Mellitus: Pathogenesis and Management-U Queensland 2005-Rand/Marshall
  Section with information on how to monitor urine for cats using Lantus (glargine) who won't allow regular blood glucose testing.

• Urinanalysis: Obtaining a Urine Sample Drs. Foster & Smith Pet Education Library

• Cornell University-Feline Health Center-Urine Monitoring Flash Movie
  Ways to Collect Test Urine and How to Read Ketone Test Strips.

• Urinalysis Dipstick Interpretation-University of Georgia
  How to read multi-screen urine testing strips.