Internal Medicine: Endocrinology: Endocrine Pancreas Flashcards
Describe the different aetiologies of diabetes mellitus in dogs?
Loss of iselets
* Infection
* Pancreatitis
* Immune mediated disease
* Hormonal/drug antagonism
What predisposes to diabetes mellitus in dogs?
- Obesity
- Endocrinopathy
- Hyperlipaemia
What is the aetiology of diabetes mellitus in cats?
Insulin reistance ± insulin deficiency
Combined with obesity, growth hormone and pancreatitis
Leads to beta cell dysfunction
What are the effects of insulin deficiency?
- Increased glucagon
- Increased gluconeogenesis
- Decreased cellular uptake of glucose
- Osmotic diuresis
- Fatty acid mobilisation- ketoacid production
What are the clinical signs of insulin deficiency/diabetes mellitus?
- PUPD
- Polyphagia
- Weight loss
With what basic tests can diabetes mellitus be diagnosed?
- History
- Clinical signs
- Haematology/Biochemistry
- Urinalysis
- Glycosylated Hb and fructosamine
What does haematology and biochemistry show for diabetes mellitus?
- Hyperglycaemia
- Elevated ALT, ALKP
- Hypertrigyceridaemia
- Urinary ketones
What does urinalysis show for diabetes mellitus?
- Low USG
- Glycosuria
- Ketonuria
- Active sediment (WBCs)
How long is diabetes treated in cats and dogs?
Dogs- life long
* Life style change
* Insulin, diet, routine
Cats- may go into remission
How is insulin used for treatment in diabetic dogs?
- Twice daily
- Feed half ration and then administer insulin
- 6-8hr later
- Second part of ration- larger portion
What drug is used for insulin in dogs/cats?
Caninsulin or Prozinc
When may synthetic insulins be more desirable?
- May provide better control in cats
- May have more physiological distribution
What dietary therapy is also used for diabetes in dogs and cats?
Dogs
* Fibre/complex CHO
Cats
* Low CHO
* High protein
Consistent feeding, consistent excercise
What oral hypoglycaemic drugs can be used for diabetes?
When are they indicated?
- Sulfonylureas (glipizide)
Not first choice- salvage
How should diabetes mellitus be monitored?
Clinical signs
* Thirst
* Appetie
* Weight gain
Urine glucose
* Afternoon sample
Glucose curve- 5-7 days for adaption
Fructosamine- 2w
Glycosylates Hb- 2-3m
What happens in an overdose of insulin?
How is it treated?
Ataxia, collapse, seizure
Tx
* Give sugary substance under tongue
* Feed ASAP
* Avoid insulin dose if imminent
What should be done for diabetic dogs if they are not eating?
- Basal insulin always needed to control glucose entry into cells
- If not eating- reduce insulin dose by 50%
DO NOT STOP
How should a glucose curve be created in clinic?
- Duplicate diet and timing of home
- Serial blood samples- 2h
- Lowest points should be within normal range (4.5 and 9mM)
When should insulin not be given based on glucose curve?
If not returned to >9mM by 12 hrs
Where can a skin prick be done for a side monitor of glucose?
Cats- ear
Dogs- lip/ear
When do wireless monitors usually stop working?
7-14 days
Often precisely inacurate- don’t show exact blood glucose but follow curve
What problems can occur with serial blood glucose curves?
- Activity can have effect- inconsistent
- Poor appetite
- Stress
What may cause recurrence of clinical signs with treated diabetes?
- Administration technique and insulin activity problems
- Insulin overdose and glucose counter-regulation
- Short duration of insulin effect
- Inadequate insulin absorption
- Circulating insulin binding Abs
- Concurrent disorders causing resistance
What are potential chronic complications of diabetes mellitus?
- Ketoacidosis
- Infections
- Lens induced uveitis
- Diabetic neuropathy
- Cataracts
- Diabetic retinopathy
If a diabetic patient is unstable what should paid attention on glucose curves?
- Is insulin effective at lowering blood glucose
- How quickly does the insulin act
- Glucose nadir- low point
- Duration of action of insulin
When investigating unstable treated diabetes patient what should be ruled out first?
- Is the owner giving injections correctly
- Correct dose and syringes
- Handled/stored appropriately
- Out of date
- Feeding regime
If insulin is not lowering the blood glucose what should be considered?
- Insulin dose < 2IU/kg increase dose
- If >2IU/kg- insulin resistance?
UTI/other disease/Insulin Abs
What should be done if the glucose nadir is the following for diabetes?:
1. < 4mmol/l
2. > 8-9mmol/l
3. 4-8 mmol/l
- Decrease insulin dose
- Increase insulin dose
- Perfect
When is longer acting insulin indicated?
When duration of action is too fast
What is overswing?
- When too much insulin is given- hypoglycaemic
- Causes- glucagon, adrenaline, cortisol production
- This then caused hyperglycaemia
Constant hypo/hyperglycaemia
What is the aetiology of diabetic ketoacidosis
- Insulin deficiency
- Insulin resistance
Increased circulating levels of diabetogenic hormones
Describe the pathogenesis of diabetic ketoacidosis
- Lipolysis of fat oxidation- insulin not inhibiting
- Produces ketoacids- causes metabolic acidosis
- Ketoacids increase ketones in the blood
- Ketones in urine causes osmotic diruesis
- Loss of H2O and electrolytes
- Causes a loss of perfusion to the kidneys
- Leading to azotaemia
- Azotaemia increases plasma osmolarity
- Causes cellular dehydration
What are the clinical signs of diabetic ketoacidosis?
- Vomiting
- Depression
- Dehydration
- Weakness
- Tachypnea
- Signs of concurrent disease
How is diabetic ketoacidosis diagnosed?
Diabetes and ketonuria
What are the goals of treatment of diabetic ketoacidosis?
Goals of therapy:
* Provide adequate amounts of insulin
* Restore water and electrolyte losses
* Correct acidosis
* Identify any concurrent illness
* Provide carbohydrate substrate
How is diabetic ketoacidosis treated?
- Potassium supplementation
- Phosphate supplementation
- Bicarbonate therapy
- Insulin therapy
- Fluid therapy
- Concurrent illness tx
- Insulin therapy
Describe insulin therapy for diabetic ketoacidosis?
- Initial loading dose- crystalline insulin (fast acting)
- Measure blood glucose every hour
- When glucose < 16mmol/l give regular insulin every 4-6 hours
- Maintain glucose 8.4-16mmol/l
- Maintain this until the patient is eating
Or
Constant low dose insulin infusion
What is an insulinoma?
What are the clinical signs?
- Functional tumour of pancreatic Beta cells producing insulin
- Causes hypoglycaemia
CS
* Often episodic
* Weakness, trembling, ataxia, seizures
* ± other neurological signs
* May have weight gain
How is insulinoma diagnosed?
- Persistent hypoglycaemia
- Normal glucose does not exclude
- Elevated insulin
- Pancreatic mass- can be small
How is insulinoma treated?
- IV glucose if needed
- Avoid excess stimulation of insulin by giving- frequent small meals, avoid simple sugars
- Prednisolone
- Oral hyperglycaemics
- Surgery
What is a gastrinoma?
- Pancreatic gastrin-producing tumour
- Gastric hyperacidity and risk of ulceration
- GI signs can be very severe
- Diagnosis: elevated gastrin levels, imaging, endoscopy
- Can be surgically removed- frequent metastases
