Diabetes in Dogs


Diabetes Mellitus (Sugar Diabetes)

Diabetes in dogs almost always requires insulin administration. Cats can sometimes be maintained for long periods of time using dietary changes and medical treatment, although it may be preferable to start treatment for diabetes with insulin in all cats and then to try to maintain the cat later without insulin if it looks like that might be possible.

There is absolutely no question in my mind that the best way to monitor pets with diabetes to aid in regulating insulin levels is for the veterinary client to learn to monitor blood sugar at home using a blood glucose meter. It appears that about 50% of veterinary clients can manage this task readily and most can manage it with encouragement from their vet and the vet's staff. Some vets are not yet ready to take on this task, though. If your vet is one of those who discourages clients from attempting home glucose monitoring I personally think that you ought to change vets, at least for the pet with diabetes, unless there is a really compelling reason to stay for reasons other than the diabetes treatment.

Purchasing one of the newer blood glucose meters that require very small blood samples is best. It can be hard at times to get blood from a pet and they tend to move around a lot during the blood drawing process, making it critical that whatever blood you can get can be utilized quickly. Spend a little extra to get a good glucose meter, such as the One Touch (tm) glucometers and it will pay off over the long run in ease of use.

Regulating insulin dosages and blood glucose levels requires a lot of communication between the veterinary client and the vet. It can be a frustrating process that can take months in some cases. There are a few patients who are just extremely difficult to regulate. Despite this most insulin regulation failures are the result of insufficient communication between the veterinarian and the client or insufficient effort on the part of either the vet or the client, or both. It is nearly always possible to regulate insulin with adequate effort on everyone's part.

Choosing the type of insulin to use can be confusing. We almost always start with human NPH insulin, either Humalin N (Rx) or Novalin NPH (Rx) because these insulins are widely available and seem to work well for us. It is important to try to stick with an insulin type once good regulation is achieved so it is helpful to use an insulin that is likely to be available when you need it. Some vets prefer PZI insulin and there is now an insulin approved for use in dogs ( Vetsulin Rx) that is pork based and may work more consistently for dogs since pork insulin is closer to dog insulin than the human products. In addition, glargine (Lantus Rx) seems to work better for some cats than other types of insulin. Since it is also a human product there is a good chance that it will be available at all times, as well. Don't change insulin types willy-nilly, but remember that there are alternatives if regulation is proving to be very difficult.

A blood glucose curve is a plot of blood sugar levels during the day. It is generally done by obtaining a blood glucose level at the time of the morning meal and every 2 to 4 hours afterwards for at least 12 to 16 hours. Plotting the blood glucose numbers on a chart allows visualization of when the level is too high, too low or just right. The pattern of rises and falls in blood glucose allow the veterinarian or the client to see if the problem is an overdose of insulin, an underdose of insulin or resistance to the effects of insulin. This is valuable information that is essential to really good regulation of insulin levels.

Even though I strongly believe in the value of blood glucose monitoring at home, it is possible to monitor sugar levels using urine testing when absolutely necessary. Monitoring urine levels doesn't work as well as monitoring blood sugar levels but is better than not monitoring at all for those who are challenged by drawing blood from their cat.

This is probably veterinary heresy but I treat pets with insulin when the owners are willing to give the insulin injections twice a day but unwilling to pay for additional lab testing or won't attempt getting blood or urine for testing at home. I am willing to do this because the pet is going to die much more quickly, in most cases, if insulin is not used. We explain how to monitor behaviors such as drinking, urinating, appetite and attitude to evaluate whether blood sugar is too low or too high and hope for the best. People get pretty good at recognizing signs of high and low blood sugar over time. If their pet makes it to a stable situation there is a good chance of long term survival as long as insulin continues to be provided. Sometimes, when there is early success, these folks start to believe their pet might make it and go ahead and purchase home glucose monitors or work with us in other ways to monitor their pet's diabetes.

Dr Mike Richards, DVM 08/2005

Diabetes control in Siberian Husky

Question: Hi Dr. Mike, You might remember corresponding with me a few months ago about my diabetic Siberian Husky, Kodi. I just wanted to let you know that she is doing great, and to tell you about her progress. When I wrote to ask your opinion about her high bg, I was having a problem with my vets who seemed all too complacent about the readings and who never ceased to discourage me about doing my own home bg testing, etc. I did turn Kodi's case over to a different vet in the practice, who did consult a specialist for me, at least. The specialist told her to tell me to keep raising Kodi's (Humulin N), so long as I kept on testing her regularly. I raised it (slowly, carefully), always still with the same basic results: an initial response to the increase, followed by return to the old problem of many hours a day in the 300s. Owing to some posts I read on two animal-diabetes listservs, I decided I wanted to try using small amounts of regular insulin to try to control Kodi's post-prandial bg increase. My vets were not encouraging about this, either. I went ahead and tried it anyway, mixing only 1 unit at first, testing, etc. I found that 2-3 units of regular insulin mixed with her N evened out her bg and kept her from going high. Whether I used 0, 1, 2, or 3 (never had to go above that) depended on her score at feeding time. I was so ecstatic about getting her bg under good control (consistently between about 90-220) that I was hardly prepared for the next development. After about four months of using R, I don't have to use it anymore. Moreover, I even dropped her back a unit of N because some of her readings were coming in a bit low, in my opinion. At the present time, at 71 lbs and after 16 months of insulin therapy, she is extremely well regulated. She does not have cataracts or any other ailment that I am aware of. I was wondering if you've ever had anyone try using the mixture of insulins for their dog. If the person is a vigilant home tester, it seems like something well worth trying.

Answer: Catherine-

Thank you for the update on Kodi. There are some dogs and cats who require mixtures of insulin in order to achieve good regulation and it is good to spread the word on this. In our practice we have only had to use this technique on one occasion but we "inherited" a patient from another practice who is being treated in this manner recently. The owner is as motivated as you are so we haven't had to do anything for this patient, yet, though.

You are obviously passing your crash course!

Mike Richards, DVM 1/18/2001

Chromium and vanadium may be helpful in diabetic cats/maybe dogs

Question: Hello Dr. Mike, You might remember me and Kodi, my diabetic Siberian Husky, from some e-mail we exchanged a few weeks ago. Thanks again. I just wanted to let you know that one of the other vets in the practice took over Kodi's case, consulted a specialist, and has helped a lot. She's still on Humulin N, but I'm raising the dose slowly and carefully and she is doing much, much better. She weighs 70 pounds, and the specialist says that her insulin can be increased a lot (up to around 32 u per injection) before we conclude she's resistant or needs a change of insulin types. Anyway, I have also added chromium picolinate to her diet (200 mcg at her evening meal) and it looks as though it might be helping maintain lower bg levels. What do you think of the efficacy of chromium picolinate for diabetes management? Are there other supplements I should consider? Thanks. Catherine

Answer: Catherine-

It is funny sometimes how subscriber questions arrive on the days I have just learned new stuff. There was an article in this month's Veterinary Medicine journal that states that chromium and vanadium may be helpful in diabetic cats, which I just read last night.

There is a reason that the article is about cats and not dogs. Cats tend to develop diabetes that mimics the adult onset diabetes seen in humans. In this case, insulin secretion decreases and insulin resistance increases, resulting in the need for supplemental insulin. In some cats, the use of insulin can be discontinued once good control of weight and diet are achieved and oral hypoglycemic agents are used. Dogs tend to develop diabetes that more closely resembles juvenile onset, insulin dependent diabetes in humans, even though it does occur more commonly in older dogs. Chromium may not be quite as specific in its actions to this type of diabetes as vanadium is, so there is more chance that chromium will be helpful in dogs but if you are careful, there probably isn't a problem with trying vanadium, either.

Chromium picolinate is dosed in humans at 200 to 1000 ug/day according the Veterinary Medicine article by Dr. Patricia Dowling and in cats at 200 ug/day. So I guess you could figure out an approximate dosage for Kodi based on her weight compared to a cat and a human.

Vanadium is reported to be more toxic in the same article and a suggested maximum dosage in humans is listed at 100 mg/day. It would probably be best not to exceed this dosage in Kodi, either. Due to the fact that vanadium is listed as being helpful for non-insulin dependent diabetes, it may not be as much benefit to Kodi, either but it is supposed to help glucose uptake into cells so that may be of some benefit.

Exercise is reported to have many benefits in the control of diabetes, too. I really think that it helps our diabetic patients when owners provide moderate exercise on a regular basis but have no strong data to back that perception up with.

Diets moderately high in fiber are reported to help with insulin regulation and control of diabetes, in general, too. Feeding several small meals a day rather than just two meals can help a lot, as well.

If your vet subscribes to Veterinary Medicine you might want to ask if you can read the whole article on vanadium and chromium.

Mike Richards, DVM 4/4/2000

Diabetes insipidus

Diabetes insipidus is a disorder in which the kidney is insensitive to a hormone, called anti-diuretic hormone (ADH) or in which there is not sufficient quantity of this hormone available. The result is excessive drinking and urination, or polydipsia and polyuria. This is one cause of changes in urinary habits that leads to problems with urination inside the house in dogs in which "housebreaking" seemed to be satisfactory prior to the disease onset.

ADH is secreted by the body when it has a need to conserve water. It makes the kidneys work harder to conserve water, which makes the urine more concentrated. When the dog can not respond to this hormone or doesn't make enough of it, the dog can not concentrate its urine. This can lead to serious problems, including death, if the dog does not have access to large quantities of water. On the other hand, it may not cause any significant problem if there is always plenty of water available. This problem can occur for a number of reasons and for no reason at all. Examples of predisposing causes are kidney failure, hyperadrenocorticism, liver disease, pyometra and others. These things affect the kidney's ability to respond. Head trauma or brain cancer can affect the body's ability to produce ADH.

This condition is treated using desmopressin acetate (DDAVP), which is a replacement for the anti-diuretic hormone. It can be administered intranasally or on the conjunctiva (the inside lining of the eyes). It is pretty effective. Unfortunately, it is also somewhat expensive. Some dogs benefit from therapy with other medications, including chlorpropamide and chlorothiazide diruretics.

The prognosis for this condition varies with the underlying cause. Dogs that have diabetes insipidus due to trauma often recover in a short time and the same is true after successful treatment of pyometra. The prognosis is good for spontaneous occurrences of diabetes insipidus as well. When it occurs for other reasons the prognosis is usually less favorable.

Mike Richards, DVM

Human glucose meters for testing pets

Question: Thanks for the newsletter, and congratulations to the new graduate!! Can I use a human glucose monitor for my dogs, and if so, what is the acceptable glucose reading? For a 30-35 lb. male Frenchie, 6 years old; and a 40+ lb. female blue heeler who is 2 and 1/2 years old? Thanks so much, Jean

Answer: Jean-

The human glucose meters are the glucometers that I was referring to. I should have made that more clear in the newsletter.

The normal range for blood glucose for dogs is around 60 to 110 mg/dl or 3.9 to 6.1 mmol/L.

The normal range for blood glucose for cats is around 70 to 140 mg/dl or 5.9 to 10 mmol/L. Some cats can get their blood sugar as high as 250 mg/dl if they are stressed, though. This makes it a little harder to interpret high glucose readings in a cat.

If there is a reason for routine screening for diabetes, like a known family tendency in one of the dog's lines, using urine glucose strips is easier than trying to draw blood and use a glucometer. If there is glucose in the urine, then checking the blood glucose would be a good idea and your vet can help you determine the best way to correct the problem.

Mike Richards, DVM 6/10/2000

Controlling Diabetes with diet

Q: Dear Dr. Mike, I have been reading through all of the questions and answers from your website and see nothing about controlling diabetes through diet only and no insulin. Our 8 year old schnauzer was diagnosed with Diabetes Mellitus on October 10th. We have not put her on insulin to date as I wanted to know if it was possible to control the diabetes with diet only. I check her glucose and keytone levels daily. The glucose is at 2000 or more mg/dl and the keytone level is negative. However, there was one day that it looked like there could have been a trace of keytones in the urine. Am I fooling myself trying to control the diabetes through diet? She is on a high fiber diet. We are feeding her Purina OM formula from the vet, and then I give her carrots for treats. When I leave for work in the morning I give her one "Select Care Treats for Dogs." This also comes from the vet. Ingredients: oat flour, apple pumace, oat bran, oat hulls, yeast culture, carrot pumace, etc. There is no sugar listed, but know there are natural sugars because of the apples. After reading your answers I became very frightened as to the fact that I have put our dog at a greater risk for major liver damage. I can't believe how fast all of this has been happening. Two weeks ago she seemed so healthy. We had taken her to the vet for some skin irritation due to a flea bite. The vet gave her a cortisone shot and put her on some antibiotics (cephalexin). Heidi goes through this experience once a year. I just read that you should not allow cortisone injections without being aware of glucose increase. Could this have hurt Heidi? Of course, the vet did not know at the time of the shot that Heidi was diabetic. Also, Heidi has had 5 seizures since 1993 that we have seen. One in l993, l994, l995, l996, and l998. They seem to last about a minute, and I try to comfort her as much as possible until she is out of danger. Could these seizures be related to diabetes? I really do have a great deal of confidence in our vet. I just wanted some additional information. Thanks, Mike and Linda

A: Mike:

I have had a number of clients try to control diabetes through diet alone, in both dogs and cats. Once in a while this approach seems to work in a cat when moderate fiber, restricted calorie diets are used and there is weight loss in an overweight cat but I can't remember this approach succeeding in a dog.

I am not aware of a any evidence that seizure activity leads to diabetes. The reverse is not true -- sometimes diabetes does lead to seizures.

It is my opinion, for what it is worth, that it would be better in most cases in dogs to control diabetes with insulin therapy rather than trying other approaches such as dietary control or oral medications. The actual risk of not treating depends on how high the blood sugar levels are and how long the diabetes has been present. I am assuming that your vet is advising you during the dietary trial and has considered these factors. Keep in close contact with your vet and schedule frequent rechecks. Treating diabetes involves close teamwork between you and your vet so it is good you have a trusting relationship and feel confident in your vet.

Mike Richards, DVM

Sudden onset Diabetes or ketoacidotic diabetes

Q: We just buried our pet Dalmatian two days ago, she was 8 years old. Several months ago she began limping trying not to use her right rear leg. We took her to our vet who diagnosed her problem as arthritis. While we gave her some pills to help with the arthritis she seemed to lose her zest for life, we attributed this to her lack of mobility. Last weekend she started vomiting repeatedily so on Monday we again to her to our vet. A check of her urine confirmed diabetes. Our vet told us she was in bad shape and even if they could control the diabetes there may be other damage to her internal organs. She had lost over 20 lbs in the last six months, (we were trying to help her lose weight to ease the arthritis problems). Most of the weight loss occurred in the last couple weeks though. On Wednesday, our vet said the sugar level was under control but she was still declining and in pain, wouldn't eat, couldn't lift her head etc. She recommended we put her down which we did. We are having a hard time accepting that she could get so bad so fast. Do you have any idea what may have been her underlying problem? I realize a dog doesn't get diabetes and three days later is gone. Thanks

A: Deb-I am sorry, but I probably will not be able to help much with your questions. There are times when diabetes occurs secondary to another problem, particularly immune mediated disorders and other hormonal illnesses. Genetic factors, obesity, some medications such as progesterones and chronic pancreatitis have also been associated with diabetes. None of these are usually associated with lameness in one limb, though. Diabetes can be a really insidious disease. The weight loss would have been a good hint but since you were attempting to make her lose weight this sign was also confusing. It is likely that she was diabetic for some time, perhaps several weeks, prior to the vomiting episode. Diabetic dogs do reasonably well until they lose most of their ability to utilize sugar. Once this happens, they burn body fat for energy almost exclusively. Fat accumulates in the liver leading to liver problems. By products of fat metabolism include ketone acids which cause acidification of the blood and severe metabolic problems. This part of the process does happen very rapidly - often within a few days. If the initial signs of diabetes are masked or missed the onset of severe diabetes can seem to be extremely sudden. We have also seen sudden onset of diabetes after severe attacks of acute pancreatitis in our practice and vomiting does occur in this case, too.

It can be very expensive to treat ketoacidotic diabetes. Even with intensive care there is a possibility of death. I am very reluctant to give up on these patients but sometimes wish that I had after losing one. These dogs are so sick and seem so miserable that I really regret attempting to treat them when they do die. I definitely can not say that your vet made a bad choice in recommending euthanasia. This is not a situation in which you are making a choice to return a pet to full health. They are still diabetic even if the treatment for the ketoacidosis is successful. In many instances it is not possible for people to care properly for a diabetic dog and that has to be considered in the initial decision to treat or not treat the ketoacidosis. Secondary damage that is already present also has to be considered.

This is a very tough and very painful situation to have to muddle through. I wish that no one had to face this kind of problem. I am sure your vet gave you her best recommendation. Sometimes it just doesn't help much to know if there was an underlying cause when the visible symptoms are severe enough to warrant euthanasia.

There is no easy way to lose a friend but some ways do seem a lot harder than others. I wish I could make it easier.

Michael Richards, DVM

Monitoring Glucose Part 1

Q: I have a 2 year old Yorkshire terrier (female) that was diagnosed several months ago with diabetes mellitus, and have been giving her (I may be wrong on the terminology) 3.5 and then 4 units a day of insulin as per or vets instructions. My wife has been the one taking her to the vet, and when I asked her if we were supposed to monitor her glucose levels I was told that it was not required.

A: When diabetes is well regulated after several months of testing, I can see extending the testing interval for things like glucose curves but I can't imagine advising no testing at all. Maybe I am misunderstanding this situation. You are really not monitoring the blood glucose in any way, based on your vet's advice? Not even with occasional glucose curve testing at the vet's or something like that?

Mike Richards, DVM

Part 2

Q: No you are not misunderstanding. We (nor our vet) have not been monitoring glucose or anything else, and while I have been concerned about this, with the limited knowledge I have on this condition, that is until I started to do some reading on the subject recently on the internet. I have been reluctant to question our vets advice. I am beginning to realize that some Vets (as well as some people) have an aversion to small (lap) dogs. Whether this is the case here or just general incompetence I have no idea, but I do know I need to take care of my dog to the best of my ability and do all I can to make sure she lives a long and happy life. If you could be so kind as to advise me of the best way to approach this I will forever in you debt. PS: Please excuse the typos in the first email, it was late at night and I was pressed for time. Sincerely Al

A: Al- Monitoring insulin levels is best accomplished using blood glucose testing and the best way to do this is by testing several samples over the course of a day (every 2 to 4 hours for at least 12 hours and preferably 16 to 24 hours). Plotting these values allows the establishment of a "blood glucose curve" --- just a visual aid for determining how well the insulin is working. Ideally, the blood glucose would be between 80 and 180 for the whole curve but this is rarely, if ever, possible to achieve. If values drop below 60 at all or above 250 for more than a few hours of the day it is best to adjust the insulin dose and recheck the blood glucose curve in a week or two. We encourage pet owners to attempt to draw blood at home and test blood glucose using one of the glucometers that can be purchased at pharmacies. Most owners have been able to do this but obviously not all pets will allow the blood collection and some owners just can't bring themselves to use the lancets to collect the sample. We have had the most success using the inside of the upper lip (rolled outwards) for blood collection but some people have used the back edge of footpads or ear margins. We have one nurse who just draws blood from a vein but most pet owners are not going to be able to do that well. If you can not do the blood testing yourself your vet can do it for you. Local emergency clinics are often adept at this and are often open all weekend, making it convenient for them to draw blood over an entire 24 hour period. You might check to see if this is an option in your area.

Regulation of the insulin level to get the best possible effect is time consuming and a little expensive but it is definitely worth it. Some pets do fine for very long periods of insulin use without much attempt to regulate the use of insulin other than careful attention to clinical signs such as drinking habits, urination frequency, weight loss, coat condition and overall health but it is hard to avoid problems like insulin shock or ketoacidosis without some monitoring of blood glucose.

Good luck with this.

Mike Richards, DVM


Q: Dear dr. Mike, I have a dog (a dachs called "Willie") who's 12 years old, and suffers from diabetes. His blood values are around 300, before and after eating, and his condition is worsening since last week. He's watering a lot, eats a lot, and loses weight. All in all, he's an old dog but still very lively. I've been looking around about diabetes, talked to my vet (who doesn't seem to be very animal-loving, I'm afraid to say) as well as to my GP. The vet, at any rate, suggests administering insulin; however, he also tells me that the risk of giving too much insulin is very high, and the dog may get hypo and fall into a coma. My GP suggested administering "Glucobay", but then I found out that this is for type II diabetes, and what my dog has looks more like type I diabetes (right?). Also, he doesn't know if Glucobay would be appropriate for a dog. I'd very much appreciate a short word of advise. I'd love to come by but unfortunately (esp. for Willie, he has to suffer the vets here) I'm living in Munich, Germany. Kindest regards, Patrick

A: Patrick- Dogs only rarely have non-insulin dependent diabetes (Type II). Most dogs require the use of insulin to regulate diabetes.

Your vet is correct, taking on the treatment of a dog with diabetes means making a big commitment in time and responsibility to your pet. Not everyone can do this as jobs, other family needs and many other things can interfere with this sort of commitment. Some dogs can be maintained on once daily insulin injections and feeding three fairly equally spaced meals a day. Many dogs require twice daily insulin injections, evenly spaced, with three to four equal meals a day at regular intervals. You have to learn to administer the insulin injections and to help in regulating the insulin levels. This usually involves screening for glucose in the urine or using a glucometer to measure blood glucose levels. Many of our clients have been able to use the blood glucose meters made for home use for their pets. They draw the blood by using the lancet device or with a hypodermic needle. Our clients seem to have the best luck getting blood from the upper lip but some people use the footpad or ear margin.

Despite the difficulties, many of our clients elect to treat their pets with insulin therapy. I am always awed by their dedication and by their ability to do this successfully. If you want to make this work, you will probably be successful, too.

Good luck with this.

Mike Richards, DVM

Diabetes with rebound hyperglycemia

Q: Hi Dr. Mike: Isn't this a small world! I was surfing the net to find out info about our 10 year old Springer with Diabetes and found your Site. I called to see if this could be the same Mike Richards I knew, and low and behold it was! We have kept up with you guys through Mom & Dad over the years, but never thought we would get in touch this way.

Lady, our Springer, was diagnosed with diabetes about eight weeks ago. Up until that time she had been healthy though a little overweight. She is 22' tall, a big Springer, and weighed @ 60 lbs. She started losing weight and being lethargic, drinking alot, and seemed sick. She was diagnosed with pancreatitis also, and given antibiotics. She was started on 12 units NPH 100mg per cc. Her urine glucose levels are up and down. We have gradually increased her to 18 units twice a day, but the glucose levels still go between 50 and 1000+. The trendline on the graph is between 600 and 800. We can't seem to get this regulated. Any suggestions? I will keep in contact. This is really a great medium!

A: Hey! That covers the last twenty years or so :) It is nice to hear from friends of old.

Getting diabetes regulated can be a real challenge. There are some things that make it a lot easier, though.

First, if your dog is reasonable about letting you get blood using the glucometers that pharmacies sell can help a lot. Blood glucose is better for regulation of insulin than urine glucose. Most of our clients find it possible to get blood and do the testing but a few have had too much trouble with it to keep it up. I'll be glad to talk to you about how to do this if you want to discuss it with your vet. If you can do blood glucose curves at home you will be able to adjust the insulin level much more precisely. This is done by drawing blood every 2 to 4 hours for 12 to 16 hours to see how the level changes over the course of the day.

Secondly, it is much better if you can feed four small meals a day when using twice daily insulin injections rather than two or even three meals. It does mean making a huge commitment to be around for your dog but it helps a lot. There may be some benefit to feeding a moderately high fiber diet as well.

Finally, don't make changes in the insulin too quickly. Give each change a few days to work before increasing the dosage. It seems to take three days or so for things to stabilize with new dosages.

Diabetes that starts out in conjunction with pancreatitis can be really hard to deal with at first since there are other pressures on the hormonal system from the pancreatitis. In addition, once in a while a dog with diabetes in conjunction with pancreatitis will suddenly experience a resurgence in insulin producing capability and a sudden "recovery" from diabetes. If you aren't thinking about that possibility it can lead to insulin overdosage. I doubt that will happen after all this time but if the pancreatitis returns and affects insulin dosage in the future, it may be good to keep this in the back of your mind.

Hope this helps.


Response: Dear Mike; Thanks for the info. I will pass it on to Cindy, a surgical specialist, so she can try to implement it. It really is so frustrating. I will keep in touch with you about the problem. Thanks again

A: There is a really good set of articles on diabetes in a recent "Clinics of North America" entitled Diabetes mellitus by Peterson and Greco. ISSN 0195-5616. I am pretty sure you get buy this issue from the publisher (W.B. Saunders Company, The Curtis Center, Independence Square West, Philadelphia PA 19106-3399.

If your vet subscribes to this journal he or she would probably be willing to let Cindy read it or borrow it (we won't let people take our journals out of the office -- but will let anyone read them and photocopy what they need).

It is nice to know you're doing well overall! (at least I'm presuming that :)


Diabetes continued

Q: Hey Dr. Mike! After reviewing your comments back to us, we have looked more carefully at the graphs we made from the data. There is a really strange pattern developing. Lady gets her insulin at 7AM and 7PM, and gets food at 7AM, 2PM and 7PM. In the morning, when glucose levels should be highest, they have been running 50 to 100 or normal. After these lows, the level at 2PM drops to zero or lower. The evening level jumps to 1000+ at 7PM. Yesterday at 2PM she jumped to 1000+ and stayed there through 7PM. This morning she was back to 100. Could these readings of 1000 after a negative be rebound hyperglycemia? What could cause this? Could she be producing enough insulin again? We are keeping a close watch on her after administering insulin to watch for hypoglycemia. Our Vet has not been very helpful with these questions and you seemed to pose some answers that we had not had before. Thanks Again!

A: This is very likely to be a rebound hyperglycemia. It may help a lot to lower the insulin dose some (we usually just go down 1 or 2 units at a time, wait a few days, evaluate again). It would be a good idea to do a glucose curve -- even if you have to leave her at the vet's all day for it. I don't think that is best since it isn't the dog's normal environment and that affects the levels a little. But is is better than not checking the glucose curve.

Mike Richards, DVM

Diabetes mellitus (high blood sugar) in a dog

Q: We have a 9 year old part sheltie female. She recently started having problems with drinking lots of water and urinating frequently. We took her to a local vet and he tested her urine and did a blood test. The blood test showed a level of 537, and said that the only way to help her was to start insulin shots and change her diet. We started her on WD dog food which is made by Science Diet and now make sure that we don't give her anything else. We would like to know if there is an alternative treatment for dogs with diabetes using an oral medication. We know that there are several medications available for humans, one of which is glipizide. Can you tell us if any of these types of medications are worth trying before going to the shots and if so which one(s) would you suggest? Thanks

A: The general consensus among veterinary internal medicine specialists we have consulted with at our practice is that oral medications for control of diabetes do not appear to work well, if at all, in dogs. There is a new medication for people that I remember seeing something about recently but I do not know if any studies have been done dealing with its use in dogs. Unfortunately, I can't even remember its name.

With the blood sugar levels you report, I think it would be best to go ahead and use insulin. I realize this is a really big commitment to make because of the need to monitor blood glucose, give injections and feed meals on a very consistent basis. Unfortunately, the alternative at this time appears to be euthanasia when the diabetes begins to have severe effects like secondary ketoacidosis or diabetic neuropathy. It is a tough situation. I wish I knew of an easier course of action than these two.

Mike Richards, DVM

Diabetes Mellitus and Hypothyroidism

Q: Dear Dr. Mike: Our 8 year old Golden Retriever was recently diagnosed with Type 1 diabetes (mellitis) & a hypothyroidism. We have had a heck of a time maintaining his glucose level. We have been monitoring his glucose a daily basis at home since his treatment started aprox. 5 weeks ago. A good thing since his vet initially recommeneded .5 cc twice a day of NPH 1 insulin which threw poor Einstien into insulin shock after about 4 days. He now receives .3 to .35 twice daily but his glucose is all over the charts....yes we keep detailed records....along with WD canned and dry. If we had taken the vet's advice and brought him back every 14 days who knows what shape he would be in now. First off, is there a less expensive alternative to the WD diet? Could we prepare his food in our kitchen? and....could there be a relationship between hypothyroidism and his onset of diabetes? Could one have caused the other? Just prior to his sudden-onset blindess and subsequent diagnosis of Diabetes he was on an injectable steroid and Rimadyl for what the vet thought was arthritis....lethargy, slowness. The vet completely missed the signs of hypothyroid, lethagy, hair bleaching, hair loss, etc. Could the arthritis regime have brought on the diabetes?? Could this be Type III?? No, we aren't looking to sue a vet, we are merely trying to find out all we can about his condition in order to maintain his quality of live for as long as possible. He is a beauitful and loving animal and deserves the best we can provide. Any and all information you can provide would be helpful. This part of southeastern Ohio is lacking in good internal vet specialists so we are reaching out through every available channel. Best regards

A: There seems to be some correlation between dogs developing one hormonal illness and an increased tendency to develop a second one but I can not remember mention of specific link between hypothyroidism and diabetes. That is probably the easiest of your questions to answer.

Everything else is either controversial or involves one practitioner's preferences over another's. Here goes, though:

Diet is an integral part of the treatment for diabetes. It is important to feed a maintenance diet which meets your dog's individual caloric needs and varies as little as possible. A golden retriever should need between 50 and 60 KCal/kg/day, according to Sherri Ihle, DVM writing in the Clinics of North America "Diabetes mellitus", May 1995, where most of the dietary information in this email comes from. For a dog receiving insulin two times a day, the optimum feeding schedule is to feed four meals a day. One at the time of each insulin injection, one in the early afternoon and one in the late evening. It is probably best to feed a high carbohydrate, medium fiber diet. You can just add fiber to your dog's normal dog food using a fiber source such as psyllium (Metamucil), canned pumpkin or other fiber source. There is some difference between fiber sources (soluble vs. insoluble) and how well they work, but it may not be clinically significant. Or you can buy a commercial food containing the proper quantities of fiber. The ones listed in Dr. Ihle's article are Prescription Diets w/d, Science Diet Maintenance Light, Theradiet Reducing (dry), Purina Fit and Trim, Purina Dog Chow - Low Calorie Formula and Cycle 3 Light (canned). The canned version of Theradiet Reducing may have more than the optimal amount of fiber and this is also true of Prescription Diet r/d. These food vary in fiber content but no one knows for sure what the optimum amount is.

Corticosteroids used chronically may predispose dogs to diabetes mellitus. I am not aware of any correlation between diabetes and the use of carprofen (Rimadyl Rx). We use a lot of corticosteroids here in the Tidewater area due to the problems with allergies in our area and we do not see a high correlation between the use of corticosteroids and diabetes in our practice.

There are a lot of different recommendations on how to start insulin therapy (dosages to start with) so it is entirely possible that your vet chose a starting value that falls within one of the recommended ranges in the literature. We usually use about 0.25U per pound of body weight as a start but I have used up to 0.5U per pound in situations in which it seemed necessary to gain control of the situation as quickly as possible.

We think that most clients with dogs can learn to draw blood using the devices that come with glucometers and recommend that owners of diabetic animals purchase a glucometer. We usually recommend spot checking the blood glucose the first two to three days after starting insulin and then running a "glucose curve" after that.

A glucose curve is simply a plot of the blood glucose level over the course of an entire day. By taking blood samples and measuring blood glucose at 2 hour intervals for 6 to 8 (or even 12)samples during the day it is possible to get an idea of the effect of the administered insulin. Often it is possible to identify a problem such as over administration of insulin, which results in very low glucose levels part of the day and very high "rebound" levels another part of the day. The more "level" the curve is during the day, the better. For us, this is the best way to fine-tune the insulin levels. Most of the time our clients catch on to what we are looking for very quickly and do most of the fine tuning themselves.

Not all pets will allow collection of blood easily. For these pets, the glucometers are not useful. It is a real challenge to try to stabilize a diabetic animal using information gathered at long intervals. It is expensive for the owners if we try to do the blood glucose curves too often. Getting the timing of when to do these down is one of the challenges of diabetes regulation.

Some vets do feel that monitoring the glucose in the urine and trying to keep it negative or only very slightly positive is an effective method of monitoring insulin administration. We thought we did OK with this before glucometers were available but we think our clients do better monitoring blood levels. Once a stable state is reached, longer testing intervals are OK. It is tempting to try to constantly fiddle with the insulin dosage but for most of our clients that seems to cause more trouble than just testing at reasonable intervals using glucose curves.

Type 1 diabetes is by far the most common in dogs. There are probably instances of type 3 diabetes (diabetes secondary to another illness, such as hyperadrenocorticism or pancreatitis) in dogs, but I think this is a relatively uncommon thing.

It is most likely that you have just not found the proper insulin dosage at this time. It is also possible that your dog may be resistant to insulin therapy due to a secondary illness but that is a lot less likely.

Dogs with other illnesses commonly test low on baseline thyroid levels. Many of the signs seen with diabetes are similar to those seen with hypothyroidism. While it is definitely possible that your dog could have both problems, it is also possible that low thyroid hormone levels are or were secondary to diabetes. It can be very difficult to rule in or rule out hypothyroidism in the face of another illness.

I hope that this will help some with your situation. When we are having great difficulty regulating a diabetic patient we do sometimes rely on a very good internal medicine specialist in our area. If the problem with regulating the insulin levels persists it may be worth asking your vet about referral to an internal medicine specialist, even if you have to make a trip to Ohio State University.

Good luck with this.

Mike Richards, DVM


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...