Fructosamine Testing & Feeding Schedules | Ask Dr. Joi

By Dr . Joi Sutton|2018-01-30T10:43:06-05:00Updated: May 11th, 2017|Pet Care, Pet Diabetes, Pet Newsletter|8 Comments
  • German Sheppard Shepperd and Cat

Oftentimes, I am amazed at how diligent the parents of diabetic pets are. Not only are you on top of your pet’s diabetes management, but you’re all so willing and wanting to learn more to keep your pets as happy and healthy as possible. Below are two exchanges I’ve recently had from pet owners that are clearly on top of what their diabetic pets need. Have a read. Maybe there is something you can grab from our interaction on fructosamine testing & feeding schedules and apply to how you are managing your sweetie!

I have a cat that is diabetic that I have not been able to regulate on insulin. We have tried Vetsulin, Prozinc and now he is on Novolin N and I still cannot get him regulated. He eats a very high protein food, some dry and some wet. He is on five units in the morning and 5 units at night. I work for a veterinarian and she doesn’t seem to think it’s a problem. Whenever we do his fructosamine test it always shows that he still is not regulated. I was wondering if you had any suggestions.

Answer: Well, to start, I’d get him off of dry food altogether. Dry food is by its very nature higher in carbs than canned food. My favorite of the canned foods is Purina DM as it only has 4% carbs. However, cats get a vote regarding what they will eat. There is a pet food composition chart on the Internet (readily Google-able) and you can compare carb contents of most of the commercial cat foods on the market. We want the carb content less than 10 percent, the lower the better for diabetic cats.

Next, I don’t run many fructosamine levels. The fructosamine test is awfully expensive and doesn’t give us as much information as a glucose curve. Rather, I prefer owners run blood glucose curves at home. If you are unable to run curves at home then fructosamine levels can be of assistance. Curves in a vet clinic are often less accurate than home testing because pets may have stress hyperglycemia in a clinic environment. A curve means testing every 2 hours from one injection until the next injection 12 hours later. If the blood glucose drops below 150 mg/dl, do it hourly until it rises again. This way we don’t miss where it bottoms out.

Curves tell us 2 things:

  1. How low does the blood glucose go? This nadir determines if we should increase or decrease the dosage
  2. how long does the insulin last for your pet? This can vary between pets and insulins.

Do you do home glucose testing? It is not only more accurate to check the blood glucose at home, it is much more affordable!

In general, Vetsulin and NPH don’t last very long in cats. PZI and glargine are the traditional choices for cats, but Levemir is gaining popularity. All 3 of these insulins are longer lasting than Vetsulin and NPH for most cats. Feeding a low carb diet with a longer acting insulin is our best chance to get a cat into remission. 5 units is a bit high for the average cat, but I’m guessing if you get rid of the dry food your vet might be able to lower the dosage.

After just now reading the article to give injections to my diabetic dog at meal time, I wonder how do I change time to fit with my schedule? My vet started shots yesterday at 11:00 and 11:00. Her usual feeding times feeding times are 9:00 and 9:00. My vet was adamant not to give injections before 12 hours interval was up.

Answer: When we adjust the time we do it gradually. Since your dog’s injection schedule was originally started at 11AM and 11PM, consider the next day doing it at 10AM and 10PM. Then the next day, shift to 9AM and 9PM. I would also check the blood glucose before the “shorted” interval as you might give a smidge less insulin for that dosage.

It sounds like you have a newly diagnosed diabetic. We have lots of archived diabetic pet articles here. I’ve been writing simple to understand (well, that’s my goal) for ADWDiabetes for 6 years now. A couple of things I’d love for you to do: get a blood glucose meter that is calibrated for animals and do your own blood glucose curves at home. This will save you a fortune and provide more accurate results for your vet to adjust the insulin dosage as needed.

Let me know if I can help you further. Education is key to a well-regulated diabetic pet!

Have a question or comment? Post below or email me at [email protected]. I always enjoy hearing from my readers!

NOTE: Consult your veterinarian first to make sure my recommendations fit your pets special health needs.

About the Author: Dr . Joi Sutton

Dr. Joi Sutton is a 1993 graduate from Oregon State University. She has practiced both in emergency medicine and general practice. Dr. Sutton has done extensive international volunteer work though Veterinary Ventures, a nonprofit organization that takes teams of veterinarians to undeveloped countries for humane medical care. She also runs a small animal practice in South Florida. Connect with Dr. Joi on LinkedIn


  1. Genevieve Martin May 15, 2017 at 6:06 pm - Reply

    I have a miniature Schnauzer recently diagnosed with Cushings Disease and Diabetes within weeks of each other. We had to take her off the Cushings meds due to pancreatitis flare up – the cause of all these new issues. She was doing great on 2Units 2x day on Vetsulin and then started frequent drinking and urination again. Have since increased her back to 3 units 2x day and still having some issues so are resuming the Cushings meds (Vetyrol 10mgs) but only 1x day to see if that helps regulate the insulin. She is on dry dog food – Royal Canin Low Fat GI due to the pancreatitis but wasn’t sure if I should now move her to the soft per the guidance with the cat above. I have the monitor, but am honestly terrified of lancing her to get the results as I feel bad enough pricking her 2x a day with the needle for the insulin as I’m not very steady with the needle and believe I cause her increased stress. Any guidance on how to overcome and/or test her glucose without causing much pain?

    • Dr Joi May 23, 2017 at 3:55 pm - Reply

      First of all, low carb diets (canned food usually lower in carb than kibble) is a big deal for diabetic cats, not or diabetic dogs. Cats are little carnivores that eat very little carbohydrate in nature. Dogs are omnivores. Diabetic cats nearly always do better in low carb diets than on moderate or high carb diets. This is not the case for dogs. Clearly you don’t want to give either species simple carbs like a sugary snack.

      The company that makes Vetoryl (the most commonly used med for cushings these days) recommends giving the Vetoryl twice daily for diabetic pets. There is less insulin resistance when the steroid levels are better controlled with twice daily dosing. Chat with your vet about this.

      You can check a blood glucose from an ear (my fave collection site for cats), from the inside of the mouth (flip the lip inside out), an elbow callus, or even a spot on the hip (have your vet clip the fur off a spot on the hip). There are lots of choices. And if the blood glucose is better under control your pet will feel much better than the little prick of a lancing device. Be sure to massage or stimulate the skin before pricking it. As your mom used to say, rubbing it does make it feel better. Don’t be terrified. Ask your vet or one of the vet techs at your clinic to help walk you through this!

      Great questions!

  2. Kikaioh May 11, 2017 at 2:26 pm - Reply

    I agree with getting off of dry food. One warning, though, about Purina DM — although it’s very low in carbs, the primary ingredient turns out to be liver, which I think isn’t good for cats to eat over a long period of time. My cat was on Purina DM for the last couple of years, until a few months ago when he seemed to be suffering from Vitamin A toxicosis I think (?), and I wound up having to switch him off to another brand of food. Luckily, there are other low-carb, primarily meat-based wet foods on the market (I currently feed him the Turkey Dinner flavor of Wellness, and his numbers seem to be good), so it might be worthwhile to look up some carb charts for different food varieties and see what’s available.

    I would also say that 5units seems incredibly high. Maybe there might be somogyi rebound going on with the shots, maybe the shot area is being overused, maybe the shots aren’t being given correctly or in a proper spot. It might help to investigate all the details of how the insulin is administered just to be sure it’s being done effectively, since that seemed to be a major problem for me for a long time before I was able to regulate my cat. Doing at-home curves is a great suggestion, since it can help to pinpoint if any rebounds are happening and if the dosage might need to be lowered a lot. Takes a lot of time and patience, but it’s worth it when things finally start to work.

    • Dr Joi May 14, 2017 at 9:40 pm - Reply

      Was the vitamin A issue documented?
      Regarding your second paragraph, you are right on track!! Good advice!

  3. Rich Lundin May 11, 2017 at 12:45 pm - Reply

    Regarding cat that can’t be regulated… Yes get off the dry food ASAP. My cat – I tried Prozinc and Novolin. I finally got her regulated with Detemir, and it tends to be just right at every 12 hrs. Fructosamine – it’s a nice to have/do. I have it done to my cat every 6 months. I only use it as a guideline. Daily testing before dosing is best. Don’t know if this person can do a test or curve, but the person does really need to check before dosing – preferably a couple hours before expected dose. Confirming that the BG is rising before dosing is important!

    • Dr Joi May 14, 2017 at 9:37 pm - Reply

      Yes, daily glucose testing is ideal for cats, particularly early after diagnosis in when our goal is to get a newly diagnosed cat into remission. I don’t judge families adversely if they are unable or unwilling to check a blood glucose before each insulin dose. Some pets are very consistent and we don’t have to check twice daily for those pets. Some pets are inconsistent and they are best serviced with a blood glucose check before each dose to help chose the dosage of insulin given. I generally have them do this check right before the meal/insulin. And curves are the best info of all. Just this month a new test for pet a1c came out. I just ordered some and my next article will be about it. 🙂

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