Obesity & related disorders in the horse Flashcards
What is cresty neck score
Independent indicator of insulin resistance
Cresty neck score was more predictive of insulin dysregulation than BCS, and this may be relevant to the diagnosis of EMS.
Scale on 1-5
Outline Obesity feeding management of horses
Remove concentrates
Lower calorie roughage
Roughage soaked to remove soluble sugars
Limit roughage intake (BUT not excessively)
Exercise where possible
Supplement with protein & water-soluble vitamins to meet RDA
eg Feed Balancer
Equine Metabolic Syndrome
Similarities to Type II DM
Hyperinsulinaemia and peripheral insulin resistance:
Recurrent laminitis frequent presenting sign
What is the single most common reason for obese ponies being presented for further veterinary investigation
Chronic lameness due to laminitis
Outline EMS diagnosis
12 hour fast
Take baseline blood glucose
Give 0.3 ml/kg 50% glucose iv &
0.1 iu/kg soluble insulin iv
Take further blood samples for glucose
@ 1m, 5m, 10m,
then q 10 mins up to 1 h,
then q 30 mins up to 2½ h
Oral Corn Syrup (Karo Light) test
Overnight fast
Measure basal glucose & insulin
0.45 mL/kg BW corn syrup (Karo Light Corn Syrup)
Remeasure glucose & insulin at 60 minutes
>110 μIU/mL measured by RIA
Advantages of oral corn syrup
higher sensitivity for ID
Mimics response to feed
Simple to perform
List test for EMS
Resting insulin concentration
Dynamic CGIT
Oral sugar/corn syrup test
Frequent sampling of blood glucose and insulin after glucose challenge
HMW Adiponectin
Sensitivity & specificity of Resting insulin concentration test
Specific for EMS if elevated but low SENS
Sensitivity & specificity of Dynamic CGIT test
Greater SENS for diagnosis than single insulin measurement, but still lower than ideal SENS. Glucose dyamics more variable than insulin
Sensitivity & specificity of Oral sugar/corn syrup test
Mimics intestinal response to feeding
Sensitivity & specificity of Frequent sampling of blood glucose and insulin after glucose challenge
Greatest sens & spec for diagnosis. Dynamic insulin response to glucose or feed challenge very informative.
Sensitivity & specificity of HMW Adiponectin test
May be useful in non obese EMS cases
Treatment for EMS
Progressive weight loss
Anti hyperglycaemic agents e.g Metformin (Improved hepatic sensitivity to insulin)
SGLT2 inhibitors e.g Canagliflozin (Decrease availability of glucose)
Treat underlying cause
Address laminitis when present:
Thyroxine supplementation
PPID
Equine Cushing’s Disease
Clinical sign of PPID
thin with poor muscling and altered fat deposition
Hypothyroidism is common in equine (T/F)
False! It is very rare
Hyperlipaemia
defined by elevated plasma triglycerides (TG)
Pathogenesis of hyperlipaemia
Particularly seen in obese animals which develop negative energy balance
Glycogen stores depleted
Fatty acids to provide energy
Excessive mobilization of fatty acids
Hepatic lipidosis
Insulin resistance
Hyperlipaemia is a more severe clinical syndrome than hyperlipidaemia (T/F)
True
Predisposions in hyperlipaemia
Suspect in any poorly obese pony/donkey
Very high index of suspicion if periparturient!
Abortion
Clinical signs of initial hyperlipaemia
Signs of depression and lethargy
Inappetence
Adipsia
Weakness
Reduced GIT motility and faecal output
Mucus-coated inspissated faeces
Clinical signs of mid hyperlipaemia
Reluctance to move
Muscle fasciculations
Intermittent abdominal pain
Diarrhoea
CNS dysfunction; ataxia, sham drinking, dysphagia, head-pressing, circling
Clinical signs of Late/terminal hyperlipaemia
Recumbency
Convulsions, champing, nystagmus, mania
Abortion
Diagnosis of hyperlipaemia
Plasma – opaque
Triglycerides >5mmol/l
Cholesterol
Liver enzymes
Liver function tests –check bile acid concentration
Hypoglycaemia, azotaemia, metabolic acidosis, electrolyte disturbances
Treatment of hyperlipaemia
Nutritional support
ID & treat underlying disease
Correct fluid & electrolyte deficits
Diurese to reduce metabolic acidosis
↓lipolysis & ↑clearance of lipids?
Exogenous insulin
Exogenous heparin
Monitoring (Clinical and Laboratory )
