Obesity In Horses Flashcards
Define obesity
A condition where excess body fat has accumulated to the extent that it may have a negative effect on health
Reduced life expectancy and/or increased health problems
How can we assess a horse for ‘fatness’ ?
BCS or CNS
What areas should you check when performing a BCS ?
Neck -3- flows smoothly into withers
Withers - 3- fat deposits
Back and Loin - 3- level back
Ribs -3 - fat over ribs
Hind Quarters
What is CNS?
What would a grade 5 look like?
Cresty Neck Scoring
Crest is so large it permanently droops to one side.
What is an issue with BCS?
Gives an indication of generalised adipocity
- may hide REGIONAL ADIPOCITY
What breeds are more likely to become obese?
Draught type
Cob type
Native (Dartmoor, exmoor )
welsh
What horses are most at risk of obesity?
Described as ‘good doers’
Animals not ridden
Summer vs winter
How are horses evolved to use fat stored?
Evolved relying on grass
Gain adipocity during summer and autumn
- Increased POMC secreted by pars intermedia (pituitary)
- Stimulates appetite and adipogenesis
Winter - food scarce, rely on fat stores
-depleted prior to spring and grass growth
What husbandry practices can broadly result in obesity?
Excess calories
Physical inactivity
What conditions are associated with obesity?
Exercise intolerance
Abnormal reproductive performance
Mesenteric lipoma
Laminitis
Equine Metabolic Syndrome (EMS)
Hyperlipaemia
Developmental Orthopaedic Disease (DOD)
How can obesity lead to abnormal reproductive performance ?
Narrows the pelvic canal and makes it more difficult for the foal to get through
Increased risk of dystocia
What problems can mesenteric lipomas cause?
On stalks within abdomen and eventually stalks wrap around a piece of intestine and strangulate — COLIC
What effect can the endocrine nature of adipose tissue have on a horse?
Increased fat
Increased adipokines
Adipokines antagonise insulin
Horses produce INCREASED insulin to counteract effect of adipokines
What is DOD?
Developmental Orthopaedic Disease
If foals and weanlings are overweight, altered insulin levels can affect growing legs
What is hyperlipaemia?
When a horse has increased energy requirement it mobilises fat tissues
Fat is mobilised as TRIGLYCERIDES (not ketones)
You get too much fat in blood which is then deposited in the liver and kidneys
Describe a typical lamintis stance.
Weight shifted onto heels to relieve painful feet.
What horses are of greatest risk of laminitis?
Phenotype of insulin dysregulation and obesity
What changes in the feet can be observed in horses with laminitis?
Abnormal growth rings
Pedal bone rotation
What epigenetic factors can affect development of a foal?
Genes can be switched on or off during late foetal and early post natal development
DEPENDENT ON MATERNAL DIET
What gene may be altered in the foal by epigenetics?
LEPTIN (and adiponectin)
Responsible for
- appetite control
- neuroendocrine function
- fuel metabolism and energy partitioning
GREATER ADIPOSITY and RISK of EMS and OBESITY later in life
How can maternal obesity affect foals?
Increase insulin resistance, low grade inflammation and ostochondrosis (part of DOD)
Effect observed until 18 months
How should calorie control be approached in horses?
SAME DMI
Grass can provide all dry matter required but high calorie so needs to be controlled
If owner MUST feed concentrates, substitute hay with CHAFF or beet pulp
What welfare issues are associated with reducing DMI?
Stereotypes
Colic
Gastric ulcers
Dental problems
Why are gastric ulcers associated with a reduced DMI intake?
Saliva is required to buffer acid in the stomach.
This is produced when horses chew
Why are dental problems associated with decreased DMI?
The horse is meant to be continually chewing and wearing down its molars
How could you restrict grass intake?
Time spent outside
Strip grazing
Grazing muzzle
Why can’t you just feed horses grass?
Deficient in some minerals
Need to add BALANCER. (Make sure its low calorie!)
What are the benefits associated with increasing exercise in horses?
Promotes glucose uptake and use by skeletal muscle - INDEPENDENT of insulin
Improves insulin sensitivity
Decreases feed intake
Other than working a horse, how else could you increase its energy expenditure?
Clip
Don’t rug
Have hay and water at opposite ends of the field - have to walk from one to the other
Circumferential strip grazing - have to walk around outside of field
How can you monitor weight loss in a horse?
Weigh tape one time per month
This is better than BCSing because BCS takes much longer to change
Why does BCS take longer to change?
Exponential scale
Have to lose a lot of weight to get value down
