Hypoglycemia - low blood sugar in dogs


Q: Dear Dr. Richards,

Thank you very much for the information on stroke and vestibular syndrome. I have another question. (My Vet is still on vacation.) Is it possible that my Yorkie's stroke-like symptoms could be caused by hypoglycemia or an electrolyte imbalance? (She suffered a week long bout of vomiting and diarrhea prior to her symptoms.) After this was suggested to me, I started giving her a little sugar in her food and water. She does seem to be feeling better and walking more normally. Although, she still seems to be a little disoriented. If hypoglycemia is possible, what is the proper way to treat this?

Again, thank you very much,


A: Debra-

It is possible for disorientation, weakness and even seizures to occur with hypoglycemia. Small breeds are more likely to become hypoglycemic from illnesses than larger breeds but most older dogs do not have much problems with this whether they are large or small. Older dogs do have problems with insulin producing tumors of the pancreas sometimes, though. This is probably the most common cause of hypoglycemia in older dogs. A temporary fix is to feed several small meals a day rather than one or two large ones. That would help until your vet got back. Then the best thing to do would be a general lab panel or blood glucose test (but I'd run the whole panel most of the time) and check for hypoglycemia. If it is present then checking another sample is a good idea. Then checking the insulin/glucose ratio on a blood sample would be a more definitive test for excess insulin. Insulinomas can be treated surgically or medically but surgery has a chance of curing the dog and medical treatment doesn't.

Good luck with this. Peripheral vestibular syndrome clears up in most cases spontaneously so response to therapy for other possible problems isn't a good way to rule it out. Discuss all of this with your vet and I'm sure he or she will help you make the right choice about how to go from here.

Mike Richards, DVM

Hunting Dog Hypoglycemia

Q: Dr. Mike-

We have a male Red Beagle that was bred for hunting Snowshoe Hares. They are fast on the trail by comparison to standard Beagles. We purchased the puppy at 6 weeks of age. He is now 10 months old and is a very intense and hard hunting dog. He weighs 27 lbs., stands 15" at the withers, and is in excellent physical condition. He had all of the necessary puppy vaccinations. He started running rabbits at 5 months old and was hunted about 4 days a week and had developed into an excellent hunter and trail dog, sometimes chasing a rabbit for 45 minutes.

When he reached 8.5 months of age, he had a seizure when running a rabbit trail that he had been on for about 30 minutes. When he went into a seizure he exhibted the following symptoms:

- Yelping like he was injured - Mouth wide open with his tongue hanging out - Eyes wide open, not blinking, not rolled back in his head - Running in tight circles, running into the small bushes and trees

On occasion he would sit on his haunches. When we would call to him, he would start toward us, then turn and run the other way. When we caught him he continued to yelp. This seizure lasted approximately 3 to 5 minutes. His gums were beet red in color. He was confused and afraid, and after the siezure was over, he was completely exhausted for the rest of the day. Four days later while hunting him he had another seizure on the third rabbit he ran. He had the same symptoms, but this time he was also frothing at the mouth. We took him to the local vet two days later for a complete physical which included baseline blood work. Everything was "OK" and his glucose level was 104.

Several days later we took him back to the clinic which is on a farm, in order to hunt closer to where we could have blood drawn. After a very short run of 3 to 5 minutes on a rabbit, we pulled the dog off the trail and immediately got him into the clinic for another glucose test. His level had dropped to 41, and at that point he was diagnosed with Hunting Dog Hypoglycemia. We have noted the only time this happens is when he is on the trail of a rabbit. He can chase in our yard with the other dogs for 1/2 hour without having a seizure. Our vet said to feed a high protein, high complex carbohydrate, and high fat diet. Feed small meals (6 times per day), and stop the dog in between rabbits and feed bread with peanut butter and honey. The problem we have with this is that the dog will not eat in the morning, or through the day. He eats only in the evening. When the dog is in the field, he will not eat anything due to the excitement of the hunt. The thing we do while in the field is squirt honey into his mouth with a squeeze bottle.

There have been several changes in the dog's life just prior to the onset of these seizures. We vaccinated with 7 way DHLPP-CV (he had 5 way DHLPP before this) we wormed with 1% Ivomec (0.3cc) instead of Panacur, the average outside temperature increased plus 10 degrees, he was hunting on grass (no snow) and the rabbit scent is much stronger on grass. There was no change in the feed, or in the schedule of feeding (once per day in the evening)

We have the following questions:

1) What can be done to eliminate the seizures when hunting? 2) Will he outgrow these problems? 3) Is there a medication that would eliminate this problem? 4) How long does it take ta complex carbohydrate to turn into the sugar he needs? 5) Does fiber slow the breakdown of carbohydrates into sugar? 6) Is this problem hereditary? 7) If honey is fed just before hunting the dog , does the honey drive up the insulin resulting in less sugar? 8) Can honey be fed during the hunt at one hour intervals to keep the dog from going into a seizure?

Unless we can come up with a better diet, we are going to try the following:

1 cup of fried hamburger 1 cup of Purina Dog Chow (27% protein, 9% fat) 1 cup white or brown rice 1/2 cup whole milk, mixed with above

Once the dog settles into the above diet, we will conduct another field test to check the glucose level again. Just before hunting, we will squirt 1/2 ounce of honey into the dog's mouth, then put the dog on a rabbit trail for 15 minutes, stop, and immediately do a glucose level check. If his glucose level is in the rage of 20 to 40 he will no longer be used for hunting.

I have enclosed copies of his blood work and notes from our local vet.

Thank you in advance for any assistance you can offer. Our goal is that our dog lead a happy, healthy life, which, if possible, will include being able to hunt.


A: Dear Terri

I have reviewed the records you sent and it is highly likely that your vet has correctly diagnosed this condition and recommended proper treatment. In most cases hunting dog hypoglycemia can be controlled by feeding small meals or treats several times during the day of the hunt. No one I spoke with knew of a way to handle this situation without being able to feed the dog several times during the day. The only thing that bothers me is that hunting dog hypoglycemia is more commonly reported to be an adult onset condition than a juvenile onset condition.

I spoke with the technical vets at Purina and at Hill's just to see if they had a food recommendation. The Purina vet felt that their prescription diet called "DCO" may be helpful due its composition but wasn't too confident it would work well enough to resolve the problem without the benefit of small feedings on hunting days. The Hill's vet felt that it was probably not possible to find a diet that would work to resolve this problem without multiple feedings on hunting days.

I reviewed the information on the Veterinary Information Network and NOAH and did not find anything that really seemed as if it would be helpful except for a a suggestion for getting dogs to eat during hunting when they are reluctant to do so. One vet had good success using Gaine's burgers or similar soft/moist type foods since many dogs find them to be very attractive and the propylene glycol in them may be beneficial for the hypoglycemic condition. It is considered to be better to feed a regular food, especially a carbohydrate based food, than to use a sugar based food source such as candy, because of rebound insulin effects -- although there are recommendations to carry candy to treat the seizure problems when they occur anyway.

I checked into hypoglycemia in human athletes using the PubMed site and there was one article recommending carbohydrate loading the day before an event and then using carbohydrate containing liquids (I forgot to save this article so I can't reference it exactly but their recommendation was to drink 100ml of the liquids every 30 to 60 minutes, I think. It should be possible to cut that dose considering the size of a beagle, maybe to something like an ounce at a time). It may be possible to condition your beagle to drink these liquids instead of water on the days you want to hunt. Also, I wouldn't rule out the high energy foods made for human athletes (energy bar type things). It may be that one of these is sufficiently attractive to make it worth a break during the hunt.

Some dogs are reported to outgrow the hypoglycemia problem when it has an early onset, so there is some hope for this as well. We have seen a hunting dog that had a lot of problems with this and then less and less problems as it got older but I don't recall the problem completely disappearing.

This is a list of rule-outs for hypoglycemia. I didn't see any evidence for any of these conditions in the labwork or history you sent, but it sometimes helps to think about other possibilities. This list is from Dr. Chastain and Dr. Ganjam's book "Clinical Endocrinology of Companion Animals":

Hypoglycemia that first occurs in young dogs:

hepatic vascular anomalies (portosystemic shunts, microvasular shunts) ketotic hypoglycemia from alanine deficiency congenital hypothyroidism glycogen storage diseases (there are several)

Adult onset hypoglycemia

insulinoma extrapancreatic tumors liver disease hypoglycemia of hunting dogs late pregnancy or heavy lactation intestinal malabsorption with weight loss

Unassociated with age

bacteremia hypopituitarism hypoadrenocorticism drug reactions or toxin exposure sulfonylureas, insulin overdose, salicylates, ethanol, antifreeze

It is important to note that blood sugar levels drop pretty rapidly in blood once it is drawn unless serum is promptly separated from the cells. Sometimes blood that is separated in serum separator tubes will still undergo a loss of glucose, since contact with cells can sometimes still occur in these tubes. While this isn't likely to be a factor in the labwork, it has to be considered.

Of the differentials that are listed, there is one that you should probably consider further testing for. Hypoadrenocorticism might be worth ruling out. In many dogs, this condition will cause high potassium and low sodium levels in the blood, which is not the case for your dog. However, there are also a number of cases of hypoadrenocorticism in which bloodwork is essentially normal. An ACTH response test would help to rule out hypoadrenocorticism. There is probably a very small chance of a liver circulatory anomoly as well. This is much less likely with the history and clinical signs you are seeing but if you wish to pursue all the options it might be worth considering a bile acid response test just to be sure that there isn't a liver disorder.

Hypoglycemia in hunting dogs is most commonly associated with dogs that are infrequently hunted and are therefore thought to be likely to be out of shape and not able to respond to a sudden need for efficient glucose metabolism. This doesn't sound like your dog but there are cases reported that seem to occur in dogs that are fit and exercised regularly.

Some dogs with seizure disorders can be induced to seizure by excitement. There is some chance that the hypoglycemia may be an incidental finding and that a seizure disorder is present. If this is the case you should eventually see seizure activity that is not related to excitement or hunting.

Your questions were: 1) what can be done to eliminate the seizures while hunting

Your vet's plan is the standard recommendation- stop and feed the dog several times during the course of hunting. Since this isn't easy without his cooperation I am hoping that one of the suggestions will work ( carbohydrate containing sport drinks, energy bar type treats or soft/moist dog food like Gaines Burgers. If it continues to be impossible to get him to eat it will be hard to control this problem if it is truly the hunting dog hypoglycemia syndrome. I think it would be worthwhile to rule out hypoadrenocorticism (Addison's disease) as well, since that is treatable.

2) Will he outgrow these problems?

Maybe. Some dogs seem to just outgrow juvenile onset sugar regulation problems. Also, working on conditioning him regularly, if that isn't being done, may be helpful. It sounds like he is probably in good physical condition, though.

3) Is there a medication for this?

Not that I am aware of or can find reference to in the literature available to me.

4) How long does it take a complex carbohydrate to turn into the sugar he needs?

It takes a while, since carbohydrates are pretty much broken down into disaccharides and monosaccharides to be absorbed into the digestive tract. The advantage of complex carbohydrates is slower absorbtion which theoretically leads to more efficient utilization. The idea is to make glycogen (the form that the body stores sugar in) so that glucose is available in times of need. When he is actually having a seizure due to hypoglycemia it is much better to use simple sugars to provide the glucose he needs --- corn syrup, sugar syrups (almost any pancake syrup), honey, fruit juices and sugar solutions.

There is another option in getting advice on this condition. You may want to ask your vet to call a veterinary school or referral facility that has a clinical nutritionist who can make suggestions for helping. I can make this contact but they are going to need specific information which your vet would be better at supplying.

If none of this helps, the good news is that most dogs with this condition do fine if they do not hunt or engage in high-energy activities. Even in dogs in which hunting continues there does not seem to be a really high risk of death from the condition, although it obviously is a risk and an interference in their ability to work.

Hope this helps some.

Mike Richards, DVM

More Hunting Dog Hypoglycemia

Answer: Terri-

I misplaced the last page of your note and consequently overlooked the rest of your questions. To sum up the answers to the rest of them:

5) Does fiber slow the breakdown of carbohydrates into sugar?

It appears to. For this reason, moderate to high fiber diets are recommended for diabetic patients in order to keep sugar absorption at slower rates which should help in the regulation of insulin levels. There is still some controversy over exactly how effective fiber is at this task but I think most vets agree that it seems to help some. In theory, that same effect should be beneficial for hypoglycemia from other causes.

6) Is this problem hereditary?

I can not answer that question with certainty in regards to hunting dog hyoglycemia. I have not seen are reference to heredity for this condition but it is more likely that heredity hasn't been studied than that it has been ruled out.

7) If honey is fed just before hunting the dog, does the honey drive up the insulin resulting in less sugar?

This question is really hard to answer. This theory has definitely been mentioned in the literature but recent studies in human athletes seem to show that glucose levels may drop to levels that would ordinarily be indicative of hypoglycemia without any clinical signs of low blood sugar levels. So the question now is whether the drop in blood glucose noticed in studies of sugar administration and exercise were actually normal or whether they were induced by the added sugar. My personal opinion is that it probably does not cause significant problems to give honey prior to hunting and several times during the hunt.

8) Can honey be fed during the hunt at one hour intervals to keep the dog from going into a seizure.?

I think so. This would match the recommendations to use carbohydrate containing liquids for human athletes on an hourly basis during long competitions.

If you wish to use a diet other than a commercial diet or to make changes to a commercial diet that are significant it is best to work with a clinical nutritionist to ensure that the additions to the diet do not cause imbalances in minerals or vitamins. If you are just going to use the alternative diet the day before hunting as a way to try to achieve carbohydrate loading it is less necessary to worry about this step. Veterinary schools usually have clinical nutritionists and they are generally very helpful. Your vet can call to review the proposed diet with a nutritionist at the veterinary school in Wisconsin.

I don't think that it is going to be possible to correct this problem with dietary changes other than supplementing energy levels in some way on the day of hunting, such as using honey, small meals or other supplements. However, I am not a nutritionist and have been wrong about issues like this before. If you hit on a successful formula for avoiding hypoglycemia it would be great to know what it was.

In your plan to evaluate blood glucose during hunting it would be best to use blood glucose levels in a couple of your other beagles as "controls", if possible. Checking blood glucose in three or four dogs under similar conditions may make it easier to evaluate how low the glucose level is in comparison to a "normal" level established among the unaffected dogs. Otherwise, it will be hard to tell whether the drop is significant since it is known that drops in blood glucose can occur during exercise without inducing clinical signs of hypoglycemia even if they might normally occur in a resting dog with similar glucose levels.

Good luck with this. It is a challenging case.

Mike Richards, DVM

Hypoglycemia possible

Q: I have a pekinese skipperke mix breed dog about 5 years old who started having what I think may be seizures. I took my dog to the veterinarian (we have been with this vet since the dog's birth) immediately after a seizure. Blood was taken etc... I am a Nuclear Medical Tech. retired and the more I see these seizures which are not daily but occur monthly I am getting the impression that my dog is having incidents of vertigo. After bringing this to the attention of the vet. I am dissatisfied with their response. Primarily due to the lackadaisical attitude of their not hearing what I am saying. Question ? How do I find out what a seizure (mild) response is in a dog? Is it similar or the same as I have seen in a human? Skipper's muscles stiffen as I have experienced dealing with human seizures but he does not lose his body functions or a has a loss of mental awareness. He spread eagles to the ground gripping the carpet and crawls to someone or to the wall and leans into it as if to stabilize.( for fear of falling?) After the incident passes, skipper vomits and then is fine. I asked the vet about possible allergies? No response negative or positive. I asked about vertigo. No response positive or negative. I treated him with that anti-flea pill from England and he had black loose bowel movements. When I took him to the vet..the vet stated that NO dogs tested had any reaction to the medication and it was completely safe. Excuse my french but bullsh-t. Anything chemically induced to sterilize a host flea has to have something reactable to it. My vet said To test this out I was to give skipper a second pill the following month. I told him to forget it. They took blood tests, physically examined my dog and x-rays for bowel problems and finally suggested exploratory surgery..that is when I guess you would call it.. I LOST FAITH in my vet. The seizure like incidents started about 6 months later. How do I find a good practicing vet in my area. Or is my medical background getting in the way of accepting my vets GOOD ADVICE?

A: I think that your vet should listen to you and should respond to your questions to the best of their ability. I just think that should be a part of the relationship that you should accept. The unfortunate thing in this case is that there may not be a good response. That always makes it hard for me to decide if someone is not responding because they don't want to say "I don't know" or if they are ignoring the question.

The problem is that I am not aware of a good way to decide if a dog has vertigo unless it has accompanying symptoms like nystagmus (rhythmic eye movement) or loss of balance. This is just one of those times when being able to ask what our patients are feeling would be really advantageous.

The other problem is that the symptoms you are describing differ slightly from a "typical" seizure, as you have already surmised. The most disturbing difference is the retention of consciousness and seeking comfort during the episodes. This would be unusual behavior for a seizure. Therefore, to me, it does make a lot of sense to look for other problems. In general, dogs do lose consciousness and they often, but not always, urinate or defecate during a seizure.

The first problem that I would want to rule out is hypoglycemia because the description of the episodes does sound more typical for this problem. Dogs seem to seek out something to lean on during hypoglycemic episodes and they often retain consciousness but exhibit signs similar to a seizure. In most cases, low blood sugar is detectable with this sort of problem if it is the cause but in some cases the hypoglycemia is transient enough to make detection difficult. In these cases it can be helpful to run glucose and insulin levels on the same sample and look at the ratio. The second thing I'd worry about is a heart problem. Muscle stiffness isn't usually seen with collapse from cardiac problems but I have talked to a cardiologist who said it can be seen. Usually dogs faint when they have heart conditions but weakness may be possible. Once I was satisfied that these conditions were not the problem and if the other blood work is normal, I think I'd be at a loss and be thinking about referral to a neurologist, if possible. I think I'd prefer that option to exploratory surgery unless I had a good idea of what I was looking for.

Allergies do seem to be able to precipitate seizure activity and they can mimic other conditions at times but it can be very frustrating to document allergic reactions of this type and I suspect it doesn't get done very often due to that.

The company that makes the flea pills (Program) does claim that there are no documented reactions to it, other than some dogs with gastric discomfort immediately after administration. At least they were saying that the last time I went to a seminar but that was a while ago. Ciba-Giegy seems like a reputable company to me but I tend to agree with you that all medications cause reactions in somebody. Sooner or later, we'll have an idea of what those reactions are. You should find a vet who you feel listens to you. Since you were previously happy with the vet you have, you might want to call and tell the veterinarian that you feel you haven't been listened to and see if that helps. Once in a while a client will tell me that --- and many times they are right. I am glad they have the faith in me to let me know and I try to do better!

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...