Diabetes is brought about by the malfunction of the endocrine glands (hormone secreting glands). There are two types of diabetes, diabetes insipidus and diabetes mellitus.
Diabetes mellitus (sugar diabetes) is characterized by insulin deficiency. A lack of available insulin causes diabetes mellitus also known as “sugar diabetes”.
Insulin helps sugar (as glucose) move into tissue cells where it is used to produce energy. If there is insufficient insulin present, or if the insulin that is present can not work because of tissue resistance, blood sugar concentrations rise.
Insulin is produced by specific cells (the Islets of Langerhans) in the pancreas. The pancreas is a gland situated near the intestines and is involved in digestion (produces digestive enzymes which are mixed with ingested food and breaks down protein, fat and carbohydrate) and the hormone insulin that regulates the amount of glucose in the blood.
Diabetes Mellitus is a state of persistent uncontrolled hyperglycaemia (abnormally high blood sugar) and may be the result of many contributory factors.
Factors that promote hyperglycaemia include anything that causes the failure of adequate insulin secretion and/or peripheral insulin resistance.
Common causes of insulin secretory failure in dogs include immune mediated B-cell destruction (caused by an infectious or toxic insult to the immune system) and chronic pancreatitis, whereas insulin resistance is often the result of obesity.
Diagnosis is performed by a urine analysis and/or fasting plasma glucose (FPG) test measures blood glucose in a dog that has not eaten anything for at least 8 hours.
Treatment of DM in dogs usually consists of treatment of the underlying causes(s), lifestyle management changes and insulin medication (injections). A crucial aspect of treating DM is adherence to lifestyle management changes, especially ensuring consistency of feeding and exercise patterns.
It is important to note that where diabetes is present because a dog is obese, DM may not be a permanent condition. Insulin therapy may be needed for only a few weeks or months, as it may be practical to treat and reduce/remove this influence (e.g. a weight loss programme) which may reduce or remove the requirement for insulin medication. However, for some dogs insulin medication may be required for the rest of the animal’s life.
It is important to stabilise the dog then continue with precisely the same dose of insulin and feeding protocol. If owners change the type of food, the amount, or the timing of feeding, OR if owners change the dosage or timing of insulin administration the dog can be easily destabilised. Regular monitoring and adjustment of dosage (under veterinary supervision) is required in the early stages of stabilizing the dog. Once stable, monitoring and dose adjustment will be as advised by your vet and based on the individual circumstances of the dog.
Good for stabilised patients with controlled glycaemia.
Diabetes insipidus is characterized by the lack of vasopressin. Vasopressin is an anti-diuretic hormone whose job is to control the kidney’s absorption of water. This quite a rare disorder and is NOT related to Diabetes Mellitus (sugar diabetes).
There are two types of Diabetes Insipidus: Central (CDI) - the problem is in the brain and Nephrogenic (NDI) - the problem is in the kidneys.
N.B. Water consumptions varies, depending on the ambient temperature and his activity level. However, as a general rule, a 12kg dog (in a temperate climate) should drink about 56ml of water per kg of weight. This translates to approx. 1.1 pints of water per 24 hours for a 12kg dog. Water consumption in excess of this amount should be investigated further to rule out any health issues.
The pituitary gland (located on the underside of the brain) produces a hormone called ADH or anti-diuretic hormone (Vasopressin).
When this hormone is required, it travels through the bloodstream to receptors in the kidneys. Once there, it is allows the dog’s body to concentrate urine and recycle water in the body. Without the hormone and the ability to use it, the dog excretes more urine than he should as a result he will be very thirsty as he tries to compensate for the fluid loss.
Sometimes, the hypothalamic-pituitary system stops making/releasing ADH. None (or very little) ADH is produced. This type of diabetes insipidus is known as "central diabetes insipidus" or CDI. It is also called Pituitary DI and it is sometimes called Neurogenic DI. This can happen because your dog has a genetic problem or because of an injury to the head, a brain tumour or for no known reason.
Occasionally the kidneys lose the ability to use ADH. In this instance, although there are sufficient hormones circulating, the dog’s kidneys do not have the ability to utilize the hormone. This type of diabetes insipidus is known as "nephrogenic diabetes insipidus" or NDI. This can happen because the dog has a genetic problem or is on medication that make it difficult for the dog's body to use ADH or has another endocrine or metabolic disorder or for no known reason.
Both CDI and NDI produce the same symptoms. Unfortunately, these symptoms can be caused by other diseases as well as DI. Therefore, it is imperative that any dog displaying these symptoms is seen by a vet as soon as possible.
No matter which type of DI your dog might have, it is VERY IMPORTANT to ensure the dog has a plentiful supply of water available at ALL TIMES. Because they are unable to conserve water (recycle), they need to drink. Without water, they can dehydrate and die in a matter of hours.
Treatment of CDI is with the replacement of ADH using the drug desmopressin. Desmopressin is also known as DDAVP®. It is usually given as intranasal drops (nose drops), oral tablet, eye drops or subcutaneous injection. The correct dose is decided by your vet as is the frequency of administration. The aim is that the drug should replace the ADH that the dog's body is lacking and so will help to control the amount of urine that he passes and so regulate the dog's water balance.
Not life threatening if treated with replacement ADH and adequate fluid intake is maintained.
With NDI the problem is not a lack of ADH being produced, it is the case that despite adequate quantities of ADH circulating the kidneys cannot utilize the hormone.
Oral hydrochlorothiazide (a thiazide diuretic) is given to help the kidneys concentrate urine. Thiazides paradoxically reduce urine output in dogs with diabetes insipidus (DI). In dogs that don't have DI, urine output would be increased. Nonsteroidal anti-inflammatory drugs (NSAIDs) may sometimes be used to good effect. Dietary measures are also useful to ensure that the level of salt in the diet is reduced and plenty of fluids should be consumed.
If your dog has diabetes insipidus and develops diarrhoea and/or vomiting, owners need to pay particular attention to make sure that they drink plenty of fluids to help prevent dehydration. If they have any vomiting and/or serious diarrhoea, a vet’s visit is advisable. Owners also need to ensure that in hot weather water is available, as dehydration will occur more rapidly.
It is equally important that dog’s don’t become overloaded with water. This can happen if water intake exceeds urination quantities and may be as a result of the dose of desmopressin being too high.
Water overload can lead to problems with the levels of salts in the dog’s blood, particularly sodium. It can make sodium levels drop too low. Low sodium levels can make the dog drowsy and confused and in severe cases can lead to a fit (seizure) and unconsciousness.
This information is provided for information purposes only and is not intended to replace professional veterinary advice.