Changes: Hometesting blood glucose

Revision as of 15:25, 25 October 2006

Many caregivers with diabetic pets test their pets' blood glucose at home using a glucometer. Testing blood glucose in a cat or dog requires a bit of practice, but those who persevere master the skill eventually. The majority of feline caregivers on the FDMB do home test.

When to test

The tests are done at least once before each insulin shot, and sometimes once more a day, about halfway between shot times, generally at the expected time of peak insulin action. While adjusting dosage, that third peak reading is vital -- the rest of the time it's just a good check once in a while. Note that the expected peak time varies by case, you'll need to determine your pet's peak time first, using some blood glucose curves. Curves are usually done on weekends or days off.

How to test

Here's a very good article^[1] about hometesting written by Dr. Lisa (of FDMB board). It has pictures of the process and is very instructional. Here are two other good links^[2]^[3].

These sites also contain helpful information about hometesting; one has a video.

Harry's Page^[4], although the information there about popular glucometers is dated.
VSPN Hometesting Video^[5]^[6]

Earflap testing for dogs:^[7]

Earflap testing for cats:^[8]

More downloadable movies re: testing for cats:^[9]^[10]^[11]^[12]^[13]

Paw testing for cats:^[14]

Step-by-Step Instructions

Here's a friendly guide, for cats, from one caregiver in the US:

Disclaimer: These are the products, steps, and tips that we followed with great success. There are lots of brands of meters, strips, lancets, and lancing pens. These are only our suggestions; they worked for us, the first time and every time. What ever tools you buy, you should read all the instructions and accompanying papers. My tips and instructions are meant to complement those that accompany your supplies. Also please fully read the articles in the first three links in the "How to Test" section above. Those are truly helpful and written by folks with lots of experience in feline diabetes. Lastly, our vet uses this very handout to all new patients.

First, once you get all your supplies gathered up, put them on the floor and let your cat smell everything. Rub the lancing device (without a lancet in it) all over your cat and click it several times so he gets used to that sound, it will be right against his ear when you click it for real, so doing it ahead of time will be helpful to the whole process.

Which brand of supplies you use is up to you -- see the Supplies category or the web_resources page for other brands.

Here's what we use:

Bayer Ascensia Contour Meter^[15](uses a .6ml drop - very tiny) and takes 15 seconds to give results. You can find it for free with the purchase of 100 test strips, usually.

The strips must match the meter - Ascensia Microfill Test Strips - they cost about $1.00 per strip.

I use a lancing device (called a pen) rather than freehand, it's just my preference. I use the One Touch Penlet Plus by Lifescan, $14.00^[16]. The lancing device that came with my meter kit was awkward and not effective. I strongly suggest buying a lancing device for this reason, you know, you get what you pay for. BD also makes a very good lancing pen.

The lancets I use are One Touch Fine Point Lancets by LifeScan, $10 for 100^[17]. They are purple. There are others by the same company that say "ultra soft" but they did not produce success for us every time the way these do. These are a bit stronger. Buy the purple ones, purple!

Read the manual and inserts completely before you use the equipment. Try testing yourself a few times so you know how it feels and how fast the equipment works.

Once you are ready to start, WASH YOUR HANDS VERY WELL, and have all your supplies at hands reach but out of the reach of the cat. I like testing on the washing machine with a soft blanket under the cat. That way the cat is at an easy-to-reach level.

Fill a sock with rice and heat it in the microwave for 45 seconds. Make sure this is not too hot, some microwaves are stronger than others. Then warm the cat's ear for a good 3 minutes, brushing him if he likes that, petting him and talking to him in a very soothing voice. Stroke the warm sock all over the cat's body and then concentrate on the ear. You have to get the blood moving in the ear so massage it too. Getting the ear warm is the key. This petting, talking and brushing is really an important part of the process. You want the cat to like the test, not fear it, so lavish praise, brush and pet so that the cat thinks this ritual is all about him.

Don't push the test strip in all the way until you are ready to test, you only have 3 minutes from that point so you'll want to push it in after you have warmed the cat's ear and are ready to go. Also, the strips are sensitive to moisture and direct sunlight (fragile if you will); so don't take the strip out until you are ready to test and be sure to close the container tighly.

Before you poke, shine a flashlight on the ear to see the vein, you don't want to hit the vein, you want to hit between the vein and the outside rim of the ear. I find that I really like using a device, (lancing pen) not free hand, it removes the burden, one click and you're done.

Now you should push the strip in all the way. Hold a cotton pad (not a cotton ball) behind the ear and set your pen to a setting of about 3. You want to poke very near the outside rim of the ear. You can do the poke from either side but if your cat has black or dark hair, doing it on the inside will be easier to see the droplet of blood. When you do the poke put a little pressure against the ear with the lancing device, this tip really helped us.

It probably will poke right thru but don't worry about that, that's why you hold the cotton pad there. Very Important: Once you poke, drop the lancing device and hold on to that ear, don't let the ear go or the cat will shake and you'll have to start over.

After you poke, if the drop of blood is too tiny, try massaging it and "pumping" it up. Remember, don't let go of the ear! Hold the tip of the strip (which you have pushed in all the way) right up to the droplet of blood and let the strip "sip" up the blood until the meter beeps. The strip needs to be full as according to your strip instructions.

Once it beeps put the meter down but make sure the strip doesn't touch anything. Now with the cotton pad, fold it over both sides of the poke and hold it there with pressure for about 30 seconds. This will prevent bruising and sore ears and is a rather important part of the whole process. Your meter has beeped now for the second time and there is your test result.

Congratulations! You are now a member of the vampire club and your cat will love you for it because now you can help control the diabetes with knowledge rather than a good guess.

Hometesting Misconceptions

Some vets discourage home blood testing on various pretexts. Thess DVMNews articles^[18]^[19] and this Canadian Veterinary Journal (CVJ)^[20] may be helpful in convincing them otherwise. Vets themselves use hand-held glucometers for a number of illness other than diabetes itself; both sepsis and insulinomas (insulin-producing tumors) cause hypoglycemia. The patients need not be diabetic to have hypoglycemia from these conditions^[21].

Some people think they will have to draw blood from one of the animal's veins to test the blood glucose level. Not true: most of those who hometest cats take a tiny amount of blood by pricking the ear, some prick the foot pad. In dogs, it is most common to prick the lip, though the ear is also possible.

In 2002, a study was done with blood samples taken by the "ear nick" technique and blood obtained by the traditional venipuncture method, comparing samples from both diabetic and non-diabetic cats. The non-diabetic cats' blood results with the ear nick test was not found to be significantly different from the blood testing using venious blood. For those with diabetes, the results regarding ear nick vs venipuncture was found to be significantly different, but the difference was not found to be clinically important. The conclusion drawn by the study indicates that the ear nick technique is a reasonable alternative to drawing blood from a vein^[22].

Vets sometimes discourage hometesting saying that it will spook the pets, making them wary of their caregivers, or could cause testing site infections. Again this turns out not to be the case^[23]. Most pets are amenable to the test once they become accustomed to the routine (and petting and a treat at test time help). Concerns about test site infections can be alleviated by using hydrogen peroxide or an antibacterial ointment on the site after the test.

Vets also sometimes discourage hometesting saying that the caregiver will become too focused on the numbers, rather than the overall condition of the pet. While the pet's overall condition is indeed an important consideration in evaluating and treating its diabetes, blood glucose readings are critical to regulating the pet and to avoiding hypoglycemia, which is caused by injecting more insulin than the pet needs at the time.

No single blood-glucose reading, whether at a vet or at home, is adequate for determining a correct insulin dosage. The first few months can be especially tricky while finding a correct dose, and there are no substitutes for frequent testing and occasional curve-plotting. These tests are best performed at home, both because vet stress causes inaccurate readings, and because you can test more frequently and regularly at home.

Some other 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.

Urine testing^[24] 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.

You may see that blood drawn when glucose levels are normal is has a lighter color then when they are high. This is due to an enzyme (glucose oxidase) in the strip reacting to the amount of glucose in the blood^[25].

References

[1] Home Blood Glucose Monitoring

[2] Testing Blood Glucose at Home

[3] Diabetic Feline Blood Glucose Monitoring At Home

[4] Harry's Page

[5] VSPN Hometesting Video-RealPlayer Version

[6] VSPN Hometesting Video-WindowsMedia Version

[7] Earflap Method for Testing Blood-Dogs

[8] Earflap Method for Testing Blood-Cats

[9] Feline Blood Testing Movie--Windows MediaPlayer Format

[10] Feline Blood Testing Movie--RealPlayer Format

[11] Feline Blood Testing Movie-Flash Version

[12] Punkin's Testing Movie-RealPlayer Version

[13] Punkin's Testing Movie-Quick Time Version

[14] Xavier Shows You How To Paw Test With His Slideshow--End Slide VERY IMPORTANT!

[15] Bayer Website-Ascensia Contour Meter

[16] LifeScan Website-OneTouch Penlet

[17] LifeScan Website--One Touch Lancets

[18] DVMNews-Capillary Blood Collection Valuable for in-Home Diabetes Management

[19] DVM News Magazine Blood Glucose Monitoring-2001

[20] Owners' Perception Re: Home Monitoring of Blood Glucose

[21] Portable Blood Glucose Meters-Means of Monitoring Dogs & Cats With Diabetes Mellitus-Clinical Techniques in Small Animal Practice-2002

[22] Glucose Concentration Comparisons: "Ear Nick" vs Venipuncture in Diabetic & Non-Diabetic Cats

[23] FDMB discussion regarding hometesting and site infections -- none found yet!

[24] DVMNews:Glucose Testing-Blood vs Urine Tests

[25] Childrenwithdiabetes.com Blood Samples for Glucose Testing Lighter-Colored When Glucose is Low

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@@ Line 116: / Line 116: @@
 *[http://www.cliniciansbrief.com/cms/portals/_default/pdfs/capsules/Cap18_July06.pdf Home Monitoring of Blood Glucose in Diabetic Patients-North American Veterinary Conference-2006]
 *[http://www.unc.edu/~pjdutche/bloodsugar/ Checking a Ferret's Blood Sugar Using the Freestyle Glucometer]
+*[http://www.royalcanin.us/documents/OSUProceedings.pdf OSU Endocrinology Symposium 2006-Monitoring of Glycemia in Dogs & Cats with Diabetes Mellitus-Reusch-Page 36]
 ==References==