Diabetes mellitus in cats is often diagnosed in cats, which ultimately affects all organs. It develops in about one in 400 cats. This is a consequence of inadequate insulin production by beta cells of the pancreas or an inadequate response of cells to insulin. Insulin is released directly into the bloodstream. It acts on the cell membranes, allowing glucose to penetrate into the cells where it is converted into energy. Without insulin, the body can not use glucose. This leads to an increase in the level of sugar in the blood (hyperglycemia). In cats suffering from diabetes, the excess of glucose is removed by the kidneys, which causes frequent urination. There is a need to compensate for increased urination by drinking more water.
Pancreatitis, hyperthyroidism, drugs like megestrol acetate (megais) and some corticosteroids can cause diabetes in cats or mimic it. Obesity is a predisposing factor for all cats. Also Burmese cats may have a genetic predisposition. In males, the risk is twice that of females. The most at risk are castrated males aged over 10 years and weighing more than 7 kilograms.
Glucosuria is sugar in the urine. If the test for glucose in the urine is positive, they suspect diabetes. However, some cats have high glucose levels in urine or blood due to stress, so a reanalysis may be necessary to confirm the result. Abnormalities in the function of the renal tubules, for example, resulting from antifreeze poisoning, can also cause high levels of glucose in the blood and urine.
Ketones (the final product of rapid or excessive decay of fatty acids) are formed in the blood of diabetic patients due to the inability to metabolize glucose. Their high level leads to a condition called ketoacidosis. It is characterized by the smell of acetone from the mouth (a sweetish smell like the smell of a liquid to remove varnish), frequent shortness of breath and, eventually, diabetic coma.
In the early stages of diabetes, the cat tries to compensate for the inability to metabolize glucose in the blood, eating more food. Later, the appetite decreases as a result of poor nutrition. Accordingly, signs of early diabetes are frequent urination, consumption of large amounts of water, large appetite and unexplained weight loss. Laboratory tests show glucose and, possibly, ketones in the urine, as well as a high level of glucose in the blood.
In more severe cases, loss of appetite, vomiting, weakness, acetone from the mouth, dehydration, shortness of breath, drowsiness and eventually coma occur. Unlike dogs, cats suffering from diabetes rarely develop cataracts. The weakness of the muscles, which is usually manifested by the unusual position of the posterior part of the cat's body that walks on the heels, and not on the fingers, is often observed if the glucose regulation is poor.
In cats, there are three types of diabetes. Cats with type I diabetes are insulin dependent, they need to receive insulin injections every day, since the beta cells of their pancreas do not produce enough insulin. In cats with type II diabetes, the pancreas can produce enough insulin, but the cat's body does not use it properly. This is the most common type of diabetes in cats. Some of these cats may also require insulin administration, others may receive tablets to monitor blood glucose levels, and diet changes are needed. Approximately 70% of all cats suffering from diabetes require at least a small amount of insulin.
The third type is known as sugar transient diabetes. There are cats who are sick with diabetes and initially require insulin administration, but after a while their body is rebuilt and they can do without insulin injections, especially if they are transferred to a diet high in protein and low in carbohydrates.