Changes

Cats may suffer from '''islet amyloidosis''' in which the protein amylin is deposited in the tissue and has directly cytotoxic effects on the beta cells.  Amylin is a protein which is produced normally in the beta cells at the same rate as insulin and has synergistic effects on many aspects of metabolism.  In situations where the synthesis of insulin is increased due to insulin resistance (see below), amylin is also produced in excess and it then forms aggregates that are deposited in the pancreatic tissue.

Cats may suffer from '''islet amyloidosis''' in which the protein amylin is deposited in the tissue and has directly cytotoxic effects on the beta cells.  Amylin is a protein which is produced normally in the beta cells at the same rate as insulin and has synergistic effects on many aspects of metabolism.  In situations where the synthesis of insulin is increased due to insulin resistance (see below), amylin is also produced in excess and it then forms aggregates that are deposited in the pancreatic tissue.

*Presence of '''specific antibodies''' in the blood that reduce the effective concentration of insulin - This is a form of immune-mediated disease that has no apparent initiating factor.

*Presence of '''specific antibodies''' in the blood that reduce the effective concentration of insulin - This is a form of immune-mediated disease that has no apparent initiating factor.

*Presence of high concentrations of '''hormones that are antagonistic to insulin''' - This occurs with many endocrine diseases that result in elevated levels of particular hormones.  Examples include [[Canine Hyperadrenocorticism - Cushing's Disease|hyperadrenocorticism]] (due to corticosteroids), [[Hypersomatotrophism - Acromegaly|acromegaly]] (due to growth hormone) and phaeochromocytoma (due to catecholamines).  Pregnancy is maintained by high blood concentrations of progesterone in small animals and this may cause '''gestational''' or type 3 diabetes and a similar phenomenon may occur during dioestrus.  Iatrogenic diabetes mellitus may be induced when high doses of corticosteroids or megoestrol acetate (a synthetic progestagen) are administered.  Even when the antagonisitic factor is withdrawn, the signs may remain if the islets of Langerhans are in a state of '''islet cell exhaustion''', a form of degeneration that results from chronic hyperstimulation.

*Presence of high concentrations of '''hormones that are antagonistic to insulin''' - This occurs with many endocrine diseases that result in elevated levels of particular hormones.  Examples include hyperadrenocorticism (due to corticosteroids), [[Hypersomatotrophism - Acromegaly|acromegaly]] (due to growth hormone) and phaeochromocytoma (due to catecholamines).  Pregnancy is maintained by high blood concentrations of progesterone in small animals and this may cause '''gestational''' or type 3 diabetes and a similar phenomenon may occur during dioestrus.  Iatrogenic diabetes mellitus may be induced when high doses of corticosteroids or megoestrol acetate (a synthetic progestagen) are administered.  Even when the antagonisitic factor is withdrawn, the signs may remain if the islets of Langerhans are in a state of '''islet cell exhaustion''', a form of degeneration that results from chronic hyperstimulation.

*Failure of peripheral tissues to respond to insulin, resulting in '''resistance''' - This is the cause of '''type 2''' diabetes mellitus which is described most commonly in obese cats.  This form of the disease occurs due to downregulation of insulin receptors, a process which is reversible initally.  As above however, chronic hyperstimulation of the beta cells may result in islet cell exhaustion and insulin insufficiency.   

*Failure of peripheral tissues to respond to insulin, resulting in '''resistance''' - This is the cause of '''type 2''' diabetes mellitus which is described most commonly in obese cats.  This form of the disease occurs due to downregulation of insulin receptors, a process which is reversible initally.  As above however, chronic hyperstimulation of the beta cells may result in islet cell exhaustion and insulin insufficiency.   

*Other factors are likely to be involved in the aetiopathogenesis of the disease, including stress, concurrent illness and genetic factors, including possible associations with particular dog leucocyte antigen (DLA) haplotypes.

*Other factors are likely to be involved in the aetiopathogenesis of the disease, including stress, concurrent illness and genetic factors, including possible associations with particular dog leucocyte antigen (DLA) haplotypes.