Diabetes mellitus is a disease caused either by a lack of insulin, or an inadequate response of the body to this hormone. After your cat has eaten, the digestive system breaks down the food into various parts. One of these is carbohydrates which are further converted into simple sugars such as glucose. Glucose is absorbed from the gut into the blood where it is transported around the body. Insulin, which is produced by “beta cells” in the pancreas, helps in the process of moving glucose into the cells of the body where it is converted into fuel. If there is insufficient insulin available, or the body responds inadequately to insulin, glucose is unable to enter cells and can build up to high concentrations in the bloodstream. The resulting condition is called hyperglycemia. As a result, an animal may behave as if it is constantly hungry (the cells are not producing fuel), but may also appear malnourished, again because the cells are unable absorb glucose.
Damage to the beta cells in the pancreas can be either temporary or permanent. The damage may be caused by a virus, infection, trauma, some medications (steroids), or even from over-work after too much sugar or carbohydrate consumption.
Diabetes mellitus is often divided into two types, depending on the origin of the condition:
Diabetes mellitus Type 1, sometimes called “juvenile diabetes” or “insulin-dependent diabetes”, is caused by the destruction of beta cells in the pancreas. Because the destruction of the cells is not reversible, the animal must be treated with an exogenous (external) source of insulin. Both cats and dogs can suffer from Type 1 diabetes.
Diabetes mellitus Type 2, sometimes called “”adult-onset diabetes” or “non-insulin-dependent diabetes”, is characterized by high blood sugar due to the body being resistant to insulin and a relative lack of insulin. Type 2 diabetes is found in cats, but not in dogs.
RISK FACTORS AND INCIDENCE
Diabetes has been diagnosed in cats of all ages, both sexes, both intact and neutered individuals and all breeds. Older cats, especially neutered males, are more susceptible to the disease. It has been reported that in the UK, Australia, and New Zealand, Burmese cats have a higher incidence of diabetes mellitus but this has not been found in North America.
Key risk factors for diabetes in cats include
- Chronic pancreatitis
- Other metabolic diseases (e.g., hyperthyroidism, Cushing’s disease, acromegaly)
- Physical inactivity
- Predominant indoor lifestyle
Between 0.2% to 1.0% of cats develop Type 1 diabetes. This incidence is expected to increase in the future.
Diabetes is one of many conditions that cause visible changes in behavior which the owner can detect. Usually, there is a gradual onset of the disease over a few weeks. By knowing the signs of diabetes, you will be able to detect the disease earlier and thereby seek an early diagnosis and treatment. The following are indications your cat may have diabetes. If your cat shows any of these, speak with your veterinarian about the possibility of diabetes:
- Excessive thirst/drinks more water than usual (polydipsia)
- Urinates more frequently, in greater volumes (polyuria) or perhaps loses urinary control
- Consistently acts as if it is hungry (polyphagia), but maintains or loses weight
- Unusually sweet-smelling or fruity breath (due to ketone production)
- Thinning, dry and dull hair
To diagnose diabetes, your veterinarian will initially conduct a urine test for the presence of glucose, ketones and/or urinary tract infection. If necessary, a blood test will then measure your cat’s blood glucose concentration. If glucose is present in your cat’s urine, a blood test will determine blood glucose concentration and fructosamine concentration. A consistently raised blood glucose concentration could indicate that your cat’s pancreas is not secreting sufficient insulin, or, your cat’s body is behaving as if it is “resistant” to the insulin being produced. Regardless of the underlying cause for the increased blood sugar, your cat is suffering from diabetes mellitus. The diagnosis is considered as confirmed when glucose is found at consistently high concentrations in blood and in urine.
Because cats can suffer from either Type 1 or Type 2 diabetes (dogs only suffer from Type 1) some cats can be treated (at least initially) with oral medications, while others require immediate insulin injections.
The objective in managing diabetes is to regulate glucose concentrations by avoiding peaks and troughs, and to reduce or eliminate the symptoms, such as excessive thirst and urination. Although diabetes can not yet be cured in cats, the condition can be successfully managed with daily insulin injections, changes in diet and/or medication. The serious chronic complications that afflict humans with diabetes mellitus are uncommon in diabetic cats. Once stabilized with proper treatment and home care, diabetic cats can live many healthy years.
Managing feline diabetes often requires daily insulin injections to restore your cat’s insulin level and control blood glucose concentrations. Each individual diabetic cat’s requirements are different, so you and your veterinarian will need to find the appropriate dose and treatment regimen. Your cat may need to stay at the veterinary clinic for several days so your cat’s response to treatment can be closely monitored. The prescribed insulin product may be specifically for diabetic cats, a human insulin product, or a human oral hypoglycemic medication. The size of the insulin dose will depend on several factors, including the weight of the cat.
Some diabetic cats may show clinical remission after a few weeks or months of treatment, i.e. they will cease requiring insulin. However, clinical remission does not mean that the diabetes has been cured; the cat’s diet and lifestyle must still be taken care of and insulin may be required again in the future.
If your cat does need daily insulin injections, you will have to learn how to do this. It can be a daunting task and at first you may feel nervous about this. This is common, but, it is easier than you probably think. After a while you will learn how to administer daily injections without stress for your cat or you.
Oral Hypoglycemic Medications
Healthy diabetic cats can sometimes be successfully treated with glipizide. This is an orally administered medication that lowers blood glucose. Although glipizide is suitable for controlling the disease in some cats, most require insulin injections to fully control their diabetes.
It is an important part of diabetes management to monitor your cat’s blood glucose concentrations. The method of monitoring will depend on you and your diabetic cat. Methods include urine glucose (and ketone) test strips, or blood glucose meters.
Diet is vitally important in helping to regulate your cat’s diabetes. Once the blood glucose levels are stabilized, you should aim to feed your cat exactly the same diet every day and at the same times of day. Many cats prefer eating small amounts throughout the day and your veterinarian will probably not try to change this. Cats require high levels of good-quality protein in their diet. A high-protein, low-carbohydrate food is ideal for a diabetic cat. Overall, the diet should be palatable, nutritious and minimize fluctuations in blood glucose. In addition, it should help maintain a healthy weight for your cat.
It is important to get regular veterinary checkups to identify possible changes in your pet’s diabetic condition. Diabetes affects cats differently over time. Changes may occur even after a long period of stabilization.
Although it often stated that diabetes can not be cured, in February 2013, Type 1 diabetes in dogs (not cats) was successfully cured using pioneering gene therapy. It seems only a matter of time before this is applied to cats.