27. Diabetes mellitus in dogs and cats Flashcards
Type 2 insulin dependent DM?
↓ Action of insulin → ↑ Blood glucose
TYPE-II (INSULIN-DEPENDENT) DM
↓ Secretion of insulin due to immune-destruction of pancreatic beta
cells, islet cell hypoplasia or pancreatic destruction
Dogs > Cats
Requires insulin injections
Pathogenesis: Autoimmune; Amyloidosis; Pancreatitis
Type 2 Non insulin dependent DM?
TYPE-II (NON-INSULIN-DEPENDENT) DM
Insulin resistance duet to diabetogenic hormones or obesity (cats)
Secretion of insulin is normal but is ineffective; Delayed response in
secreting insulin or the tissues are resistant
Cats > Dogs
Alternative case: NIDDM → Prolonged hyperglycaemia → Glucose
toxicity of pancreatic cells → Destruction → IDDM
Pathogenesis: Excess counterregulatory hormones; Obesity
Consequences of incr. C Glucose?
CONSEQUENCES OF ↑ EC GLUCOSE
↑ Blood glucose
§ Glucosuria → ↓ Blood K+, Na+ & PO4
-
§ IC Dehydration → Hyperglycaemic coma
§ Glycation of proteins → Cataracts; Retinopathy;
Peripheral neuropathy; Glomerulosclerosis
Consequences of decr. in IC Glucose?
CONSEQUENCES OF ↓ IC GLUCOSE
↑ Lipolysis
§ Ketonemia → Ketonuria; Acidosis; Ketoacidosis coma
§ Weight loss
§ Hyperlipidaemia → Fatty liver
↑ Gluconeogenesis → Protein synthesis → Weakness; Poor wound
healing; ↑ Susceptibility to infection
DM in dogs Clinical signs?
DM In Dogs
Predisposed
Middle/Old-aged dogs > Young dogs; Intact females
Poodle; Dachshund; Terriers; Beagle; Puli; Labrador retriever
CLINICAL SIGNS
Uncomplicated DM (Good prognosis)
§ PU/PD § Flaking skin
§ Weight loss § Cystitis
§ Dehydration § Cataracts
§ Hepatomegaly § Retinopathy
§ Dull coat § Paresis
Complicated DM (Poor prognosis)
All the above CSx, as well as…
CSx associated with diabetic ketoacidosis
§ Kussmaul breathing § Anorexia
§ Acetone-smelling breath § Vomiting
§ Lethargy § Coma
§ Weakness
CSx associated with hyperglycaemic hyperosmolar syndrome
§ Restlessness § Ataxia
§ Nystagmus § Convulsions
CSx associated with pancreatitis
§ Abdominal pain § Vomiting
§ Diarrhoea § Lethargy
CSx associated with EPI
§ Poorly-digested faeces § Flatulence
§ Foul-smelling faeces
CSx associated with Cushing’s syndrome: Acromegaly
§ ↑ Blood glucose
§ ↑ ALT; ↑ ALP ↑ ALKP
§ ↑ BUN/Creatinine
§ ↿⇂ K+
§ ↑ Amylase; ↑ Lipase; ↑ Cholesterol (lipaemia)
§ ↑ Progesterone; ↑ Cortisol; ↑ GH
§ Metabolic acidosis
Urinalysis
§ Glucosuria (>12 mmol/l)
§ Evidence of UTI; Bacteriuria – Sediment & culture
§ Ketonuria
Fasting hyperglycaemia
Blood glucose is measured on at least two occasions after >8 hours
of fasting
Fructosamine
↑ Levels; Used in cats as fructosamine levels are not affected by
stress hyperglycaemia
Differentiation of of Type-I & Type-II: IV glucose tolerance test
Diagnosis of DM?
DIAGNOSIS
History, physical exam & Lab. D
Abdominal US
§ Diffuse hepatomegaly § Cystitis
§ Enlarged adrenal glands § Ovarian cysts
§ Pancreatitis § Uterine cysts
§ Nephropathy
Treatment Insulin therapy?
TREATMENT - INSULIN THERAPY
Caninsulin
Half the dose of insulin in cases of anorexia or vomiting
Warn the owner of the CSx of hypoglycaemia:
§ Excitement § Tremor
§ Falling convulsions § Coma
§ Weakness
Blood glucose after 6 hours post-insulin = 4-9mmol/l
Treatment of hypoglycaemia: Put honey on the lips; Give an extra
meal; Skip the following insulin dose
Follow-up
§ Follow-up appointment within 2 weeks of starting
§ Once stable: Follow up appointments every 3-6 months
Potential complications
§ Hypoglycaemia (see above)
§ Somogyi effect (post-hypoglycaemic hyperglycaemia)
PU/PD; Hyperglycaemia
Requires a serial blood glucose measurement →
↓ Insulin dose
§ Stress-induced hyperglycaemia
§ Short action of insulin (insulin resistance)
Treatment- others?
TREATMENT – OTHERS
Ovariectomy: ↓ Risk of insulin resistance → ↓ Insulin demand
Diet
Composition and amount should remain constant
§ ↑ Protein; ↑ Fibre; Complex carbohydrates
§ 1 portion given a few minutes before each insulin dose
Treatment of ketoacidosis
§ Volume replenishment: Ringer + KCl
§ Regular (human) insulin – Hmge
§ K+ replacement
§ Bicarbonate therapy
DM in cats?
DM In Cats
More common in male cats
CLINICAL SIGNS
Good prognosis
§ PU/PD
§ Weight loss; Polyphagia
§ Cataracts
§ Neuropathy → Plantigrade posture of hind limbs
LAB. D
§ Hepatic lipidosis is more severe: ↑ TBr
§ Hypokalaemia
§ Hyperthyroidism: Baseline serum T4 or serum free T4
§ Stress hyperglycaemia
Often found in healthy cats
Rarely exceeds >16mmol/l
Glucose should be tested at home or the fructosamine levels should
be measured instead
TREATMENT – INSULIN THERAPY
Type-I DM
Glipizide; Glargine
↑ Insulin secretion → ↓ Blood glucose after 1-2 months
Type-II DM
Cats with Type-II DM may be manageable without insulin –
§ Diet (difficult to control in cats)
§ Exercise
§ Ovariohysterectomy
