It is a bit less common in cats, but can also occur in other animals ranging from horses to pet birds and ferrets.
Types of Canine Diabetes
Both types of canine diabetes, diabetes mellitus and diabetes insipidus, differ in many ways from humane diabetes. In humans, diabetes mellitus comes in three types: Type 1, Type 2 and gestational diabetes. Type 1, formerly known as juvenile diabetes or insulin-dependent diabetes is usually first diagnosed in children, teenagers, or young adults. In this type of diabes the body's immune system has attacked and destroyed the betal cells of the pancreas. Type 2, formerly called adult-onset diabetes or noninsulin-dependent diabetes, can occur at any age and is the most common form of diabetes. In this type of diabetes a condition of insulin resistance in which fat, muscle, and liver cells do not use insulin properly. Dogs and cats with diabetes mellitus are almost always insulin dependent, regardless of age at onset.
Gestational diabetes is a third type of diabetes mellitus that can occur in women during the late stages of pregnancy. In dogs this type of diabetes has the same symptoms as Canine Diabetes Mellitus and the treatment is similar; diet and exercise and/or insulin injections. Studies suggest that Gestational Diabetes Mellitus affects mainly middle-aged bitches in the 2nd half of pregnancy with a breed predisposition toward Nordic Spitz breeds. The Prognosis is usually good as unlike Diabetes Mellitus, Gestational Diabetes GDM may resolve within days to weeks after pregnancy has ended.
In diabetes insipidus de body fails to retain water. Diabetes insipidus (DI) may be central or nephrogenic.
For both types of diabetes, symptoms are an increase in urination and drinking, but for different reasons. In diabetes insipidus, either the body is not producing enough of the hormone that tells the kidneys to retain water or the kidneys fail to respond to this hormone. In diabetes mellitus, the culprit is a lack of insulin, a hormone that helps to efficiently use sugars, fats and proteins. Basically, the body has enough provisions but has no means to deliver them where they are needed. The glucose that should be going to body cells is excreted in the urine, creating more urine and a greater need to urinate.
Occurance and Causes
One similarity between the human and animal condition is that diabetes mellitus is more common in overweight pets and overweight people. The most common cause of onset in animals is related to pancreatitis. Being overweight increases your pet's likelihood of having pancreatitis and possibly developing diabetes mellitus. The average age of adult-onset diabetes is usually listed as 50 years in humans and 5 years in dogs. The peak age seen in dogs is 7 to 9 years. Among dogs, females are more likely to get diabetes, whereas in cats the condition is more common among males. Any dog breed can be affected, but some breeds at increased risk for diabetes mellitus include the Australian terrier, Samoyed, Schnauzer (miniature and standard), Bichon frise, Cairn terrier, Keeshond, Spitz, Fox terrier and the Poodle (miniature and standard).
Central Diabetes insipidus can occur if there is damage to the part of the brain that produces the anti-diuretic hormone ADH. Potential causes of this kind of damage can be trauma or cancer. Most cases are "idiopathic"; in other words, there is no known cause. Nephrogenic (originating from the kidneys) diabetes insipidus is a very rare congenital disorder that also occurs for no known reason. Nephrogenic diabetes insipidus results from renal insensitivity to ADH, caused by a congenital malformation or secondary to another problem, such as hyperadrenocorticism, hypokalemia or pyometra.
To confirm that your pet has diabetes insipidus, your veterinarian may ask you to do a modified water deprivation test. A pet deprived of water will normally show a concentration of the urine.
It is caused by either failure to produce anti-diuretic hormone (ADH) or inability of the renal tubules to properly respond to ADH. When this is not the case it is a sign that the body fails to properly reabsorb water either because of a failure to produce anti-diuretic hormone (ADH) or inability of the renal tubules to properly respond to ADH. This failure to properly reabsorb water is called diabetes insipidus (DI), whereas a deficiency of insulin secretions by the pancreas causes Diabetes Mellitus.
Note that there are important contraindications for performing the modified water deprivation test. Performing the test if these conditions are present may be life-threatening! If an animal is dehydrated, it is already releasing the maximum amount of ADH. If an animal is known to have renal disease (and testing should be performed to ensure that it does not!), the renal tubules will be unable to respond appropriately to ADH during the test.
The symptoms of canine diabetes are not specific to diabetes alone. In order to rule out to rule out other common causes of excessive thirst and urination, including your veterinarian will perform the following diagostic tests such as a urinalysis and urine culture, complete blood count, bile acid test, tests of the adrenal gland, thyroid hormone test and X-rays or ultrasound, depending on the type of diabetes suspected.
When you are bringing your pet to the vet for any illness it is a good precaution to fast your dog for at least 12 hours. With no food intake it will be easier to perform certain tets and the blood analysis will reflect the 'real' blood status, indepedently of the food ingested. A high amount of glucose indicates that diabetes mellitus is likely.
Consequences and Precautions
Pets with diabetes mellitus are more susceptible to develop urinary tract infections. However it is not clear whether this is due to the elevated blood sugar levels that make the pet more prone to infections or to the general debility (weakness) of poorly regulated diabetes which makes such infections more common.
There is no cure for diabetes in humans or animals. Right now only the conditions associated with the disease can be treated. Canine diabetes must be treated and monitored properly, otherwise the animal will suffer and die. For pets with diabetes insipidus, your veterinarian can prescribe medication that may help decrease the frequency of urination. For pets with diabetes mellitus, insulin must be injected once or twice daily for the rest of your pet's life.
Most oral hypoglycemic substances only work if the pancreas is still producing some insulin. This is why oral medications are ineffective in dogs (because dogs almost always have type I diabetes mellitus).
Monitoring is important because the amount of insulin your pet needs could change throughout the pet's lifetime. So insulin should be monitored on a regular basis by a veterinarian. In addition, your pet should be on a veterinarian-recommended diet (low-carbohydrate, low-fat, high-fiber). Owners should also follow the NO EAT, NO TREAT(ment) rule: first feed your diabetic pet, wait a half hour and then give the insulin injection.
Some veterinarians also recommend that your pet be neutered. Not only can changes in your pet's reproductive hormonal cycle make insulin regulation difficult, but your pet may pass the condition to its offspring because the tendency to develop diabetes is hereditary. Likewise, dogs with congenital nephrogenic DI should not be bred in case there is a genetic predisposition to the disorder.