Glucose comes from the diet. When an animal goes without food, the body must break down fat, stored starches, and protein to supply calories for the hungry cells. Proteins and starches may be converted into glucose. Fat, however, requires different processing which can lead to the production of ketones rather than glucose. Ketones are another type of fuel which the body can use in a pinch but the detection of ketones indicates that something very wrong is happening in the patient's metabolism. Ketones may be detected in the urine of starving animals as massive fat mobilization is required for ketone formation. Ketones can also be detected in diabetic ketoacidosis, a severe complication of unregulated diabetes so it is helpful to periodically monitor for ketones in a diabetic patient’s urine. The point, for now, is that body fat cannot be converted into glucose; in times of extreme fat burning (such as in starvation), ketones are a fat burning byproduct.
IN THE DIABETIC ANIMAL THERE ISN'T ENOUGH INSULIN WHICH MEANS:
* The cells cannot receive glucose from the blood because there is no insulin to permit it.
* The body is unable to detect the glucose present in the blood and is fooled into thinking starvation is occurring.
* Protein, starch, and fat break-down occurs as in starvation.
Yet, all along there has been plenty of glucose in the blood. In fact, by now, there is a large excess of glucose in the blood as all resources have been mobilized. Still, without insulin, this bounty of fuel cannot get to the tissues that need it.
The normal kidney is able to prevent glucose loss in urine. In the diabetic animal, there is so much glucose in the blood that the kidney is overwhelmed and glucose spills into the urine and is lost. Glucose is able to draw water with it into the urine. This leads to excess urine production and excess thirst to keep up with the fluid loss in excess urine production.
Levels of sugar in the brain control appetite. Without insulin, the brain becomes sugar deprived and the animal is constantly hungry, yet they may lose weight due to improper use of nutrients from the diet.
THUS THE MAIN CLINICAL SIGNS OF DIABETES MELLITUS ARE:
* Excessive eating
* Excessive drinking
* Excessive urination
* Weight loss
DIAGNOSING DIABETES
The diagnosis of diabetes is made by finding a large increase in blood sugar and a large amount of sugar in the urine. Animals, especially cats, stressed by having a blood sample drawn, can have a temporary increase in blood sugar, but there is no sugar in the urine. A blood screen of other organs is obtained to look for changes in the liver, kidney and pancreas. A urine sample may be cultured to look for infection of the kidneys or bladder. Diabetic patients with ketoacidosis may have an elevation of waste products that are normally removed by the kidneys.
It is usually fairly clear from the history and tests showing dramatic glucose elevations in the blood (and usually the presence of glucose in the urine, too) that diabetes mellitus is the diagnosis. Some pets are able to substantially raise their blood sugars from stress (such as might occur when a sensitive, sick, and anxious patient goes the vet’s office). This could create misleading test results. If there is any question about the diagnosis, a test called a fructosamine level may be requested. This test reflects an average blood glucose level over the past several weeks so if this is also elevated, a one time elevated glucose can be distinguished from the persistant elevations of true diabetes mellitus. The fructosamine test is also used in monitoring therapy for diabetes mellitus.
Note, in the dog, sugars can enter the lens of the eye causing rapid cataract formation. Because the lens of the cat is different, this phenomenon occurs only in dogs.
Another common symptom of diabetes mellitus is urinary tract infection. All the sugar in the urine makes the bladder an excellent incubator for bacteria. Antibiotics are necessary to clear up such an infection when it occurs and some monitoring may be needed to help detect these infections.
WHO IS AT RISK FOR GETTING DIABETES?
Diabetes most commonly occurs in middle age to older dogs and cats, but occasionally occurs in young animals. When diabetes occurs in young animals, it is often genetic and may occur in related animals. Diabetes mellitus occurs more commonly in female dogs and in male cats.
Certain conditions predispose a dog or cat to developing diabetes. Animals that are overweight or those with inflammation of the pancreas are predisposed to developing diabetes. Some drugs can interfere with insulin, leading to diabetes. Glucocorticoids, which are cortisone-type drugs, and hormones used for heat control are drugs that are most likely to cause diabetes. These are commonly used drugs and only a small percentage of animals receiving these drugs develop diabetes after long term use.
TREATING THE DIABETIC PATIENT
Diabetes is managed long term by the injection of insulin by the owner once or twice a day. Some diabetic cats can be treated with oral medications instead of insulin injections, but the oral medications are rarely effective in the dog.
Insulin comes from different sources including beef or pork pancreas and a human genetically engineered form called Humulin. The availability of animal-source insulins continues to decline.
In general, cats and small dogs need insulin injections more frequently, usually twice daily, compared to large breed dogs that may only require one dose of insulin daily. The action of insulin varies in each individual and some large dogs will need 2 insulin shots daily. The insulin needs of the individual animal are determined by collecting small amounts of blood for glucose (sugar) levels every 1-2 hours for 12-24 hours. This is called an insulin-glucose-response curve. When insulin treatment is first begun, it is often necessary to perform several insulin-glucose-response curves to determine:
* which insulin type to use
* how much insulin to give
* how often to give insulin
* when is the best time to feed the animal
The animal's insulin needs may change over time requiring a change in insulin type or frequency of injection. Insulin- glucose- response curves are usually performed several days after a change in insulin is made.
Before you give insulin injections to your pet, your veterinarian will show you how to:
* handle insulin
* use a syringe
* draw insulin from the bottle in the correct amount
* give your pet the insulin shot
Insulin is fragile and will become less effective or even inactive, if it gets too hot or cold, or is shaken vigorously. Pay attention to the expiration date on the bottle. Discard insulin that is outdated.
You may be able to practice using water and giving the "shot" to an object such as a piece of fruit until you are comfortable using needles, syringes and drawing accurate amounts of fluid into a syringe.
TYPE I AND TYPE II DIABETES MELLITUS?
Diabetes mellitus is a classical disease in humans and most of us have heard some of the terms used in its description. In humans, diabetes is broken down into two forms: Type I and Type II. These are also referred to as "juvenile onset" and "adult onset" diabetes or "insulin dependent" and "non-insulin dependent” diabetes. In short, type 1 is the type where the pancreas produces no insulin at all, and type 2 is the type where the pancreas produces some insulin but not enough. Virtually all dogs have "insulin dependent diabetes" and must be treated with insulin. Most cats have "non-insulin dependent diabetes." This might suggest that most cats can get away without insulin injections but that is not the case at all. Instead, for cats, there is potential for the diabetes to actually resolve if the pancreas improves its insulin-secreting ability. Insulin injections are needed to treat most diabetic cats but for some cats, the situation is mild enough for oral medication to suffice. Good glucose control and proper diet can resolve the diabetes in some lucky cats but virtually never in diabetic dogs.
WHEN TO RETURN TO THE HOSPITAL/WHAT TO WATCH FOR:
Your pet will probably require re-regulation at some point. During re-regulation periods, expect a curve to be run a week or two after each adjustment in insulin dose. Bring your pet in for a re-check exam and glucose curve if you note any of the following:
* the pet seems to feel ill.
* the pet is losing weight.
* the pet has a ravenous appetite or loses its appetite.
* the pet seems to be drinking or urinating excessively.
* the pet becomes disoriented or groggy.
* the presence of ketones in the urine for three days in a row.
It is important for diabetic pets to have their teeth cleaned annually. Dental tartar seeds the body with bacteria and when blood sugar levels run high, infections in important organs can take root. The kidneys are particularly vulnerable.
INSULIN SHOCK
If your pet appears wobbly or drunken, his/her blood sugar level may have dropped too low. This occurs after an insulin overdose. First try to get your pet to eat. If the pet will not eat, administer light Karo syrup at a dose of one tablespoon per 5 pounds. If no improvement occurs, immediately see your veterinarian for emergency treatment. When your pet is more stable, a glucose curve will be needed to determine a more appropriate insulin dose).
SOME PETS ARE DIFFICULT TO REGULATE
* Some pets seem to require re-regulation frequently. There may be an underlying reason to sort out. Here are some possibilities should your pet seem to fit in this category:
Improper administration of insulin. If possible, have your doctor observe you giving the insulin to your pet. Your insulin may be out of date.
* Rapid insulin metabolism. Insulin wears off quickly in some animals. Your pet may require a different type of insulin or a second injection during the day.
* Insulin overdose may actually lead to elevated glucose levels (and clinical signs of diabetes mellitus) at the end of the day. In these cases, excess drinking, eating, or urinating are seen in the afternoon and evening but not in the morning.
* Steroid administration (such as prednisone, prednisolone etc.) will interfere with insulin.
* Progesterone, a female hormone, also interferes with insulin. Unspayed female diabetics should be spayed once they are sufficiently regulated.
FEEDING THE DIABETIC PET
Regulation is achieved via a balance of diet, excercise, and insulin. Realizing that special diets are not always attractive to pets, there are some ideal foods which should at least be offered.
The most up-to-date choice for cats is a low carbohydrate high protein diet such as Hill’s M/D diet or Purina’s CNM-DM diet. These diets promote weight loss in obese diabetics and are available in both canned and dry formulations. For dogs, high fiber diets are still in favor as fiber seems to help sensitize the pet to insulin.
One should avoid soft-moist diets as sugars are used to preserve them. Breads and sweet treats should be avoided. If it is not possible to change the pet’s diet, then regulation will just have to be worked out around whatever the pet will eat.
DIABETES Q&A:
How common is diabetes in dogs and cats?
Diabetes usually affects less than 1% of dogs and cats. But experts believe that it is on the rise.
Is diabetes in my pet the same as diabetes in people?
The two conditions are very similar. In fact, your veterinarian will be using medication, equipment, and monitoring systems that are similar to those used for diabetic people.
Can diabetes lead to other health problems?
Yes. Dogs and cats with diabetes can develop other health problems, usually after living with diabetes for a year or more. For dogs, a common complication of diabetes is cataract formation. Persistently high blood glucose levels can make the lens of the eye opaque, causing blindness. For cats, weakness of the hind legs is a common complication. Persistently high blood glucose levels may damage nerves, causing weakness and muscle wasting. For both dogs and cats, controlling high blood glucose levels can lead to healthier outcomes. For this reason, early diagnosis of diabetes in your dog or cat is important.
Will diabetes affect my dog or cat’s life expectancy?
Today, with effective treatment and monitoring, a diabetic dog or cat should have the same life expectancy as a non-diabetic dog or cat of the same age. Early diagnosis and appropriate treatment helps diabetic pets maintain a good quality of life.
Is my dog or cat at risk for diabetes?
While diabetes has been diagnosed in dogs and cats of all ages, genders, and breeds, certain pets are at greater risk for the disease.
Risk factors in dogs
• Age (middle-aged to older dogs are more affected)
• Unspayed females
• Genetics
• Obesity
• Breed—these breeds have a higher risk for developing diabetes: – Cocker Spaniels – Dachshunds – Doberman Pinschers – German Shepherds – Golden Retrievers – Labrador Retrievers – Pomeranians – Terriers – Toy Poodles
Risk factors in cats
• Age (older cats are more susceptible)
• Neutered males
• Genetics
• Other insulin-resistant disorders or diseases, such as chronic pancreatitis (inflammation of the pancreas) or hyperthyroidism (overproduction of thyroid hormones)
• Obesity
• Physical inactivity
• Indoor lifestyle
Are there warning signs I should be aware of?
Some common signs of diabetes in dogs and cats include:
• Excessive thirst
• Excessive urination—your pet produces more urine per day or has “accidents” in the house (dogs) or outside the litterbox
(cats)
• Excessive hunger while losing weight
• Lethargy (less active/sleeps more)
• Cloudy eyes (dogs)
• Doesn’t groom (cats)
• Thinning, dry, and dull hair
How will my veterinarian test my pet for diabetes?
Your veterinarian may begin by performing a general health examination and asking questions about any signs your pet may be displaying. Then, a sample of your pet’s urine will be tested for the presence of glucose (a type of sugar) or ketones (acids produced by the body as it breaks down fat instead of glucose for energy). If glucose is present in your pet’s urine, your veterinarian will then test your pet’s blood to determine the blood glucose level. A diabetes diagnosis is considered definite when persistently high glucose levels are found in both the blood and urine.
How do I take care of a pet with diabetes?
Although there is no cure for diabetes, the disease can be successfully managed with the help of your veterinarian.
* Daily insulin injections are usually required to restore a pet’s insulin level and control blood glucose levels. Many owners are anxious about giving injections, but it’s easier than you think, and you can quickly learn how to handle the dosing routine with little stress for you or your pet. Diet plays a vital role in helping to keep your pet’s diabetes regulated. Your veterinarian can recommend a diet that’s best suited to the needs of your pet. A high-quality, consistent source of protein is an essential part of any diabetic diet.
* High-protein, low-carbohydrate foods are currently recommended for diabetic cats because they provide the extra energy cats need to get through their active days, without the extra carbs that can turn into excess sugar. It is important to feed your pet based on its ideal body weight. Consistent timing and size of meals is also very important. Exercise can help dogs with diabetes, but it needs to be regulated because activity affects blood glucose levels. It’s best to create a consistent exercise routine for your diabetic dog and stick to it. (There is no clear recommendation for exercise in diabetic cats because their activity is difficult to regulate.)
* Regular veterinary checkups can help identify changes in your pet’s condition and help you to manage this disease successfully over time. Managing your dog or cat’s diabetes will require some effort, but the rewards are well worth it. Pets whose diabetes is under control have normal thirst, appetite, urination, and activity levels. Their weight is generally stable and they are less likely to develop complications.
Diabetes mellitus, the medical name for diabetes, is a disease caused by a lack of insulin, or the inability of the body to utilize the insulin properly, that affects the level of glucose, or sugar, in your dog or cat’s blood.
In order to understand the problems involved in diabetes mellitus it is necessary to understand something of the normal body's metabolism. The cells of the body require a sugar known as glucose for food and they depend on the bloodstream to bring glucose to them. They cannot, however, absorb and utilize glucose unless a hormone known as insulin is present. This special hormone, insulin, is produced by the pancreas. Insulin can be considered to be a key that unlocks the door separating our cells from the sugars in our bloodstream.
