There are four main reasons for a diabetic cat or dog
being difficult to stabilise, these are:
Problems
with the insulin/administration or routine
Rapid
metabolism of insulin
Insulin
induced hyperglycaemia (Somogyi overswing)
Insulin
resistance
An initial thorough history can often ascertain if the
problem is due to the first of these causes. Some important questions include:
Insulin
- is it the right type? In date? Has it been stored correctly? Mixed gently?
Syringes
- correct ones?
Examine
the injection site for any reaction and check injection technique
Is
the owner still feeding the prescribed diet?
In
dogs, is exercise regular?
If no cause has been identified perform a glucose curve
Rapid Metabolism of Insulin
Usually
seen in patients on once daily lente which it is not lasting 24 hours
Action:
change to twice daily injections
Insulin Induced Hyperglycaemia = Somoygi overswing
The
dose has often been increased too rapidly, causing hypoglycaemia, compensatory
mechanisms then lead
to hyperglycaemia. NB morning glucosuria is noted but an increase in dose
would make the problem worse.
Action
- reduce insulin dose to a starting dose
Insulin Resistance
Insulin
resistance is defined as a dose > 2.2 iu/kg
There
is no response to insulin. NB. This pattern can also occur on lower doses
during stabilisation i.e. before
insulin 'kicks in'.
Action:
increase dose to attain best stability whilst looking for an underlying
cause
NB
High doses of insulin are not dangerous in resistant animals but it does
indicate the presence of a concurrent
problem.
Some
causes of insulin resistance include:
Problems
with the insulin
Obesity
Progesterone
in entire females
Infection,
especially urinary, dental
Steroids/Hyperadrenocorticism
Acromegaly
Pancreatitis/EPI
Hypo
or hyperthyroidism
Anti-insulin
antibodies
Renal/
or hepatic disease
Stress
in cats causes apparent resistance |