Stereotypies in Horses Flashcards
Give examples of stereotypic behaviour in horses
Wood chewing
-> Leading to Crib-Biting
Wind sucking
How did crib biting used to be treated?
Surgical intervention - cutting the muscles and nerves of the neck
What are the proposed reasons for crib biting?
Alleviates boredom - no evidence
Alleviates stress - no evidence
What is the difficulty with cross sectional studies of crib biting?
- mature populations -> population bias - culling!
- Sample size means studies usually look at abnormal behaviour not specifically crib biting
- Any measurements taken to potentially look at cause/effect -> Have these factors caused the problem or have the yards responded by implementing changes?
- Impossible to work out cause and effect
What is an odds ratio?
The ratio of odds in one group compared to a baseline/control group
- Odds are probability that an event occurs : cf probability that it will not
- Quantifies an extent to which a factor is associated with increased/decreased risk
What are the links between feeding and abnormal behaviours in horses? Give studies.
McGreevy 1995, Redbo 1998, Bachmann 2003 - AB associated with Low forage ration, high concentrate ration, non straw bedding
- Thousands of horses in each study
What are crib biting horses at higher risk of developing?
Entrapment of the SI in the epiploic foramen - Archer et al. Colonic obstruction and distension - Hillyer 2001 NOT at higher risk of ALL types of colic
What is the relationship between oroceacal transit time and crib biting?
OCTT ^ than normal when CB horses are prevented from crib biting
OCTT is the same as normal when allowed to crib bite
What is the relationship between gastric ulcers and crib biting in foals? Study?
Mucosal lining of CB foals significantly more enfaced, dry and ulcerated than normal foals
- Nicol 2002
Does crib biting show rebound?
YES - therefore an adaptive behaviour? Definitely one some horses are motivated to perform
How does adding antacid to the diet effect crib biting?
Pioneered by Willard - reduces crib biting
Dose related effect found
What is the potential causal link between crib biting and physiological factors?
An adaptive attempt to reduce gut acidity or speed gut transit time?
- Biting -> ^ saliva outflow
- Houpt showde that crib biting -> release of small amounts of saliva
Outline a study by Nicol on crib biting
CB and normal foals < 1 year
No other attempts had been made to stop the behaviour
3 months on standard diet or antacid supplement
Gastroscoped
Stomach of antacid horses improved, CB tended to decrease
- foals that CB excessively (2000s/hour) were not as affected by the diet treatment
What is the average age of onset of crib biting?
20 weeks (Badnell-Waters et al.)
Can foals start to crib bite before weaning?
Yes
