Diabetes mellitus in the cat: a review

About 80% of diabetic cats suffer from type 2 diabetes which is characterized by reduced insulin secretion from beta-cells and by insulin resistance. As in humans cats experienced a change in life habits and eating conditions over the last years leading to a tremendous increase in the prevalence of obesity. In both species obesity is one of the major risk factors for the development of type 2 diabetes. Treatment should be initiated immediately after diagnosis. In Zurich, therapy consists of application of an intermediate-acting insulin and dietary management. In the latter the use of diets with reduced carbohydrate content seems to be of utmost importance. We recently found that the percentage of cats with a transient course of diabetes increases from previous 25% to 50-70% when a diet with strongly reduced carbohydrate content is fed.     

Diabetes mellitus caused by pancreatitis in a bull

This paper describes a 6-year-old Simmental bull with diabetes mellitus. The animal was referred to our clinic because of severe weight loss and chronic indigestion. Clinical examination revealed markedly disturbed general condition, impaired forestomach function and polyuria. There was aciduria, glucosuria and ketonuria. The most important biochemical findings were severe hyperglycemia, markedly increased activities of hepatic enzymes and severe metabolic acidosis. Plasma concentrations of insulin, insulin-like growth factor-I, thyroxine and 3,5,3'-triiodothyronine were lower than normal, whereas those of glucagon were higher than normal. Based on these findings, a diagnosis (secondary) diabetes mellitus was made. The bull was slaughtered and histological examination revealed mixed cell pancreatitis with severe degeneration of islet cells. Immunohistochemical examination of the pancreas showed that very few insulin-, glucagon-, somatostatin- and pancreatic polypeptide, insulin-like growth factor-I and adrenomedullin-producing islet cells were present.     

Diabetes mellitus and bilateral cataracts in a kitten

An 18-week-old male domestic long-hair kitten was presented with a history of polyuria and polydipsia for several weeks. The general condition was unremarkable, but the kitten was considerably smaller than expected for the age and showed cataracts in both eyes. Serum glucose concentrations were persistently elevated and based on clinical findings and an elevated serum fructosamine concentration, a diagnosis of diabetes mellitus was established. Diabetes mellitus is not commonly diagnosed in young kittens, nor are cataracts recognised as a frequent feature of this disease in cats. The cataracts progressed in spite of the insulin therapy and the kitten was euthanised 10 weeks after referral. Histopathological examination of the pancreas revealed few and small islets of Langerhans compared to the examination of pancreas from a healthy kitten of the same age. Histopathological changes in the eyes included cataracts affecting both cortex and nucleus.     

Diabetes mellitus in cats.

Feline diabetes is a multifactorial disease with genetic and environmental factors, including diet, excess body weight, and physical inactivity, involved in its pathogenesis. Although type 2 diabetes is most common in cats, most cats are insulin-dependent at the time of diagnosis. If good glycemic control can be achieved early after diagnosis, a substantial proportion of diabetic cats go into clinical remission. Diabetic remission may be facilitated by using a low-carbohydrate-high-protein diet combined with a long-acting insulin, such as glargine, administered twice daily. Rather than just controlling clinical signs, these new treatment modalities make curing feline diabetes a realistic goal for practitioners.     

Diabetes mellitus in a koala (Phascolarctos cinereus)

Objective To describe a case of diabetes mellitus in a koala (Phascolarctos cinereus).
Design A case report with controls.
Procedures We describe clinical and laboratory findings in a 6-year-old, free-living, female koala presented with traumatic injury and subsequently found to have polydipsia, hyperglycaemia and glucosuria. Over a 5 week period, serum biochemical analyses, haematological examinations, urinal-yses, measurement of serum insulin and fructosamine concentrations, necropsy, histopathological examination of a range of tissues and immunohistochemical examination of the pancreas for insulin-containing cells were done. For reference purposes, serum insulin and fructosamine concentrations were determined in four and two healthy koalas, respectively, and three healthy koalas pancreases were examined histo-logically and immunohistochemically.
Results The koala had persistent hyperglycaemia, hyperlipidaemia, hyponatraemia, hypochloraemia and glucosuria. Serum insulin concentration of the diabetic koala was only marginally smaller than that of healthy koalas, but all concentrations were smaller than reference concentrations in dogs and people. Fructosamine concentration did not allow the diabetic koala to be distinguished from healthy koalas and concentrations of all koala analytes were greater than expected for healthy dogs and people. Histopathological examination revealed extensive degeneration of pancreatic islet cells and fatty infiltration of hepatocytes. Immunoperoxidase staining revealed decreased or absent insulin in the b cells of the affected koala.
Conclusion Clinical signs, clinicopathological results and histopathological changes were consistent with diabetes mellitus. The pathogenesis of the condition could not be determined but may have been related to the administration of a parenteral corticosteroid preparation, the stress of capture or tissue damage and inflammation.     

Diabetes mellitus in a 6-month-old Charolais heifer calf

This unthrifty heifer calf was thin, weak and had a dull haircoat. Urinalysis and blood work revealed glycosuria, ketonuria, hypoproteinemia, and hyperglycemia. Euthanasia and necropsy were performed, revealing multifocal intersitial lymphocytic infiltration, an absence of islet cells, and a positive stain for bovine viral diarrhea virus in the pancreas.     

Diabetes mellitus associated with pancreatic endocrine insufficiency in a kitten

Diabetes mellitus, characterised by persistent hyperglycaemia and glucosuria, was diagnosed in a six-week-old kitten. Pancreatic sections contained low numbers of atypically small islets and immunohistochemistry demonstrated pancreatic endocrine insufficiency with virtually no production of any islet hormones. There was no inflammatory infiltration of the islets, as seen in the form of diabetes mellitus characteristic of juvenile humans.     

Diabetes mellitus: an update

Diabetes mellitus is characterized by disturbances of carbohydrate, lipid and protein metabolism and glucose intolerance. Several factors are known to contribute to the disease, ie, obesity, immune-mediated insulin resistance, and the diabetogenic hormones glucagon, growth hormone and glucocorticoids. Recently, a number of developments have taken place in the management of human diabetes mellitus which may be applicable to dogs and cats. These include the use of diets high in soluble, non-absorbable carbohydrates which lower post-prandial increases in blood glucose. The more complex causes of instability, ie, insulin-induced hyperglycaemia, rapid metabolism of insulin and insulin resistance can be diagnosed by hospitalizing the patient and measuring blood glucose at four hour intervals for 24 hours. In human medicine, new techniques for controlling diabetes mellitus are pancreatic implants, constant infusion pumps for insulin and the use of the hormone somatostatin which suppresses glucagon secretion, but not all may be applicable to veterinary medicine.     

Diabetes mellitus associated with bilateral granulosa cell tumors in a mare

Both ovaries in a 10-year-old American Saddle Horse mare were determined to be larger than normal. The mare had problems with infertility during the preceding 3 years. Clinical evaluation revealed that the mare was polyuric, polydypsic, hyperinsulinemic, and hyperglycemic, and had reduced tolerance to exogenous glucose. Bilateral granulosa cell tumors were identified on histologic examination of the ovaries. The precise mechanism for the secondary diabetes mellitus was not determined; however, the cause was suspected to be a result of the synthesis and release of a hormonal substance by the tumor that affected carbohydrate metabolism and resulted in decreased peripheral sensitivity to insulin.     

Diabetes mellitus after resection of hepatocellular carcinoma with hypoglycemia in a dog

A 10-year-old male beagle was referred to us with seizure related to hypoglycemia and a large intraabdominal mass. Based on various types of imaging and a laparoscopic biopsy, the intraabdominal mass was diagnosed as a hepatocellular carcinoma (HCC) of the quadrate lobe. The hypoglycemia was suspected to be associated with the HCC. After lobectomy of the quadrate lobe was performed, blood glucose levels continued to increase to higher than normal values and sugar was detected in the urine. The dog was diagnosed as diabetes mellitus (DM) and was treated with insulin for over two years after the surgery.     

Diabetes mellitus in the juvenile dog: a report of four cases.

In four cases of diabetes mellitus in juvenile dogs, clinical and clinicopathologic findings were similar to those of juvenile onset diabetes mellitus in man. However, histopathologic findings varied from the usual findings in the human disease, and lack of plasma insulin was not proved in the canine cases.