Home blood glucose monitoring


This section contains general principles about home blood glucose testing for pets. The different techniques used to obtain a blood sample from cats and dogs are described.  Detailed instructions are given for the ear and paw prick methods for cats, and the lip and leg-callous stick for dogs.

Important Disclaimer
Managing diabetes is very complicated. Blood glucose (BG) readings can change depending on food consumption, exercise, stress, and normal daily fluctuations. There may also be other diseases or conditions that are effecting your pet's health. Home blood glucose monitoring should be performed in consultation with your veterinarian.

Purpose of Home Blood Glucose Monitoring
Home BG monitoring is a useful tool to help you and your veterinarian get your pet’s diabetes regulated. It can be used to determine how well the current type and dose of insulin is controlling the diabetes. This determination is best done under typical daily conditions where the pet’s feeding, exercise, and stress levels are normal. One common problem with doing BG testing in the vet’s office is that many pets, especially cats, become severely stressed, refuse to eat, are confined to a cage for a long period of time, then restrained for a blood test. These are not normal conditions and the BG values obtained at the vet’s office may not accurately reflect what the BG is doing on a typical day.

If your pet’s diabetes is pretty well regulated, home BG monitoring can be used to check the BG on an occasional basis or to fine tune the control. You can perform a BG test at any time, quickly and conveniently.

If your pet's diabetes is difficult to regulate, home BG monitoring can be used to obtain the information that is necessary for your vet to determine the appropriate adjustments to the insulin therapy.

Testing Habits of Owners  
Read the results of a survey of owner on the petdiabetes mailing list. Owners were asked to characterize their home bg testing habits.  You can also read reasons why people do, or do not perform home bg testing.

Will My Pet Hate Me?
Many owners are discouraged from doing home bg monitoring because the vet suggests that the pricks may make the pet dislike the owner.  None of the people I've spoken with who do home bg monitoring have had this problem.  Sure, this is not the pet's favorite activity, but it is relatively quick and painless. But not all pets will tolerate being restrained or having a prick performed. If you have a pet who hates being handled, lightly restrained, or is otherwise uncooperative, home bg testing may not be appropriate for you and your pet.  Even if your pet is cooperative, you do not want to become "prick-happy".  You and your vet can discuss the appropriate amount of home bg testing for your pet. Some vets also believe that the home bg meters are inaccurate - this is not true. These meters are relied on by human diabetics for their daily diabetes management, and for the the purposes of diabetes regulation in pets, these meters have adequate accuracy.

Will I Hurt My Pet?
Probably not. Some vets suggest that the ear can be seriously damaged doing an ear prick.  Of course it is possible to cause a bruise, an infection, or a more serious injury that requires veterinary attention, but in over three years of corresponding with other owners, I have never heard of an owner having any problems with excessive bleeding, bruising, infection, tearing, or any other problems.  By taking proper precautions, these methods can be safely used on your pet. If a problem does arise, contact your veterinarian for advice. 

Which Meter Should I Purchase For My Pet?
There are several very good meters for use with pets. These meters require a very small blood sample and have test strips that use capillary action to "suck" the blood into the test chamber. Always be sure to read, understand, and follow the instructions provided with your meter and the test strips.

Where to Prick

  • Dogs and Cats  
    Clipping a claw too short in order to get blood is not recommended.  This is very painful for the pet and can not be used on a regular basis.
  • Cats  
    The edge of the ear, or a paw pad work well. You will have to determine the best site for you cat. Some cats hate their paws being touched, while others hate their ears being played with. At first, we tried drawing blood from a front paw vein, but our cat was not cooperative. Unless you have a very cooperative cat, I would not recommend this method. You only need one drop of blood, and one of the prick methods usually works well.

    For the ear prick, there is a small blood vessel that runs around the outer edge of the catís ear. To locate the blood vessel hold a flashlight (or sit near a bright lamp) with the light shining into the inside of the ear. Look on the back (furry side) of the ear. You should see the a thin red line - this is the blood vessel that you will prick.

    How Donna does ear pricks on Barney.
    How Barb does paw pricks on Rusty
  • Dogs
    Ear pricks usually do not work on a dog because they don't have the prominent marginal vein that cats do.  Most dog owners who perform home bg testing prick the inside of the upper lip.  Have your dog lay on its side and gently lift the upper lip and roll it outward so you can work on the inside surface. The area near the canine tooth is often a good spot. Wipe the area with a clean cloth so all saliva is removed.  Pricking towards the edge of the lip often works well. You will have to figure out the spot that works best for your dog. Dog owners who use the lip prick technique report it is very easy, and it does not hurt the dog. Some even do it while the dog is sleeping.  Be careful that your dog will allow you to do this and you don't get bitten.  Another owner has success pricking the outside of the lip

    Other sites that owners prick include: a paw pad, the calloused area on the leg, the chin area, a pinch of skin on the rump. Others have had their vet show them how to draw a tiny amount of blood from their dog's leg vein. An unused insulin syringe is perfect for this - it has a very tiny needle.

    How Pat does the inside lip sticks on Chance
    How Joan does the outside lip sticks on Bayou

    How owners stick the calloused area of a leg
    How Majie pricks the quick of Cinder's nail

General Precautions

  • Keep everything very clean. Thoroughly wash your hands with soap and water. Have a clean work surface or put out a clean towel to lay things on. Do not touch the tip of the lancet.
  • The prick site must be clean and dry before you prick it. If the prick area is dirty wash it with warm water. You must wait until the area is completely dry before you can perform the prick. Moisture will cause the blood drop to spread out and it will be difficult to perform the BG test. Moisture will also dilute the blood sample and cause a faulty BG reading.

    If you are pricking a cat's ear, it must be warm. It is very hard to get a drop of blood from a cold, or even cool ear. Warm the ear by massaging your cat's head and ears or use a warm washcloth inside a plastic bag or a rice bag you can heat in the microwave. Whatever you use, make sure it will not burn your pet.

    If you are pricking a paw pad, it will also help if the paw is warm.
  • Gently restrain your pet. This procedure requires keeping the pet calm and still for a few minutes. The pet must be relatively relaxed. If you cause a lot of stress to your pet while trying to restrain it you may not get a useful  BG reading. This is particularly true of cats, because their bg can become elevated very quickly just because of stress. Of course there may be a little struggling, but if the pet becomes highly agitated, I would wait 15-30 minutes and try again. Ask your veterinarian to show you how to properly restrain your pet. NEVER use excessive force.
  • Controlling bleeding. After you get the blood sample in the meter, let the meter do its work and attend to the pet’s ear (or wherever you did the prick).  Hold a gauze square firmly (not too tight) at the prick site for about 30 seconds. This should be more than enough time for the bleeding to stop. I have never had a problem with excessive bleeding. If the site continues to bleed, keep applying gentle pressure for another minute. Don't "peek" to see if the bleeding has stopped. Just firmly hold the spot and keep your pet calm. If the bleeding does not stop or if a large bruise forms, call your veterinarian for advice.
  • Bruising. A small red spot may form after the prick. This is where a small amount of blood has leaked from the blood vessel and is trapped beneath the skin. A small bruise is ok (the size of a grain of rice) and will go away in a day or two. Watch for any large bruising, swelling, fluid accumulation, warmth in the area, or infection. If you think any of these are happening call your veterinarian for advice.

What The Numbers Mean
The BG value tells how much glucose is in blood. Meters in the U.S. report the units in mg/dL - that is milligrams of glucose per deciliter of blood. Normal values are around 80-120 mg/dL.  Meters in other countries (U.K., Canada, Australia) may report in millimoles per liter (mmoles/L) and normal values range from about 4.4 to 6.7 mmoles/L. When discussing bg values on the internet, be sure you are talking in the same units. You can use the information and chart to convert the values.  The difference in units won't be a problem when you're talking with your vet because you'll be using the same measuring system.

This section is not to give advice on what to do when you get a specific BG value. That is for you and your veterinarian to discuss. Your vet should have told you what the signs of hypoglycemia are and what to do to treat it. I will say that our cat has had a few low BG readings. We immediately fed him and watched him very closely for any signs of hypoglycemia. Be aware that your pet can have very low BG and not show any outward signs of hypoglycemia. Again, it is very important that you have discussed hypoglycemia and the immediate treatment with your vet.

Your vet will help you interpret the bg numbers and decide if any changes are needed in your pet's insulin dose, insulin type, or other aspects of the daily care routine. 

ThingsTo Remember

  • Follow the instructions that come with the meter and the test strips. Failure to follow the instructions may result in a faulty BG reading. 
  • Make sure the  meter is calibrated according to the instructions.
  • Try to repeat the BG test if a result seems faulty - either high or low.  Some meters (notable Bayer's glucometer elite) will give you a faulty low reading even if you didn't get enough blood into the test strip. 
  • DO NOT base any decisions on just a few tests. An exception is if you get a very low bg reading.  Then you should immediately treat your pet for hypoglycemia. 
  • Consult with your veterinarian.  

This is how some owners perform BG tests on their pet. The ideas are for you to use or modify to best suit the needs of you and your pet. 

Tips For The Glucometer Elite
This is a great meter for doing home bg tests on pets. It is easy to use and requires a very small drop of blood. The test strip automatically pulls the drop of blood into the test chamber, so you don't have to try to drip the blood onto the strip. Also, you can move the meter up to the pet - you don't have to keep the meter laying flat on a table.

Partially insert the test strip before the pick, then fully insert it (you hear a beep) just before you are ready to do the prick. The meter beeps when the test strip is correctly inserted. After the beep, the meter allows 3 minutes to get a drop of blood. The 3 minute time is a battery saving function of the meter. The test strip is still good after 3 minutes.

If you can't get a drop of blood in 3 minutes, remove the test strip, wait a few seconds, then re-insert the strip. This will give you another 3 minutes.

You must get the required amount of blood into the test strip all at once. The meter beeps when it has enough blood. If you try to get blood into the meter and the meter doesn't beep, you can NOT do another prick, then get more blood into the strip until it beeps. The BG value may be invalid. If you don't get enough blood on the first try, discard the test strip, use a new test strip, and try again. One "fault" of the glucometer elite is that is can "beep" to tell you it has enough blood, when it really doesn't. Look at the test strip and compare it to the picture of a "full" test strip in the gluc. Elite users manual. If you question the validity of a test, try to repeat it.   Also, be sure your meter is properly coded to the right "F code".  A coding strip comes with each new box of test strips.

Bayer has a new meter, the "Dex".  Some owners prefer this model because it has a wheel of test strips that stay in the meter, so you don't have to fuss with a test strip for each test. The Dex is more expensive than the elite, but both models work very well.

Other Sources Of Information
Your vet should be able to help with most questions about your technique.

If you have questions about the meter, read the instruction book or call the 800 phone number for the manufacturer. Many of the popular meters, the web site, and users manual link are available here. Most manufacturers have an 800 number that you can call for questions.

Many members of the Petdiabetes E-mail list perform home bg testing. If you would like to discuss the pros and cons of home testing with people who actually do it, they are a great source of information.  There are also members who do not do home bg testing, so you can get both sides of the story.

Home BG Testing Index
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Updated August 2001
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