Equine Sterotypies

Question 1

Problem Behaviours and pscycological needs

Answer 1

• Psychological needs of horses
  ~ Stimulation – mind (linked to intelligence) and body (physical activity)
  ~ Social animals (issues on own or can see but cant interact = fustration)
• Abnormal / problem behaviours
  ~ Food related e.g. amount of fibre, amount of protein in diet,
  ~ Amount and regularity of exercise (meant to be constantly on the move, norm in stables or small padocks)
• Stereotypies
  ~ Linked to boredom? ~ e.g. increased time in stable

Question 2

Sterotypies - def

Answer 2

= monotonous pattern of behaviour with fixed elements and no apparent consumatory goal

e.g. Cribbing (4 – 10%) ( clamp onto something, inhakles gas into stomach)
Weaving (3.25 – 4.6%)
Box-walking (2.2 – 2.3%)
Wood-chewing (11.8 – 30.3%) more proble behaviour

Question 3

Difference between stereotypic behaviours and those that are learned behaviours

Answer 3

• Goals? - not sterotypie if goal to get something/somewhere
• Repetition? - and is idnetical (diff each timen = no)
• Arousal? yes = stero
• Eating?
• Threat / punishment? cant stop = stero

Question 4

Consequences of sterotypies

Answer 4

• Loss of value (around 37% of market value)
• Dental problems (warn down/lose teeth) – upper incisors – weight loss as struggle to eat
• Chronic wounds and hair loss (e.g. weaving, muscle stretching)
• Other owner’s pressure (kept in envrio with other horses, other owners dont want that horse around theirs)

Question 5

Common misconceptions of sterotypies (marsden 2002)

Answer 5

• “Learnt” by copying - little evidence to support observational learning
• Cause lameness - no but may exacerbate (extra pressure on limbs)
• Boredom – stereotypies occur when arousal levels are high (disturbance, eating) not at quiet times
• Wind is swallowed – no, it is burped up! Chronic GI disorders i.e. gastric ulcers can predispose to wind-sucking, crib biting, not the other way round (uncomfortable from ulcures and find relief in wind sucking)

actually Initiated under stressful conditions and function as coping mechanism

Question 6

Neurophysiology - process

Answer 6

• endogenous opioids (due to arousal +ve/-ve (stimulation)) block receptors on VTA
• VTA = ventral tegmental area (releases dopamine) variety of opiod receptiors and vary in quantity
• Dopamine
• NA = nucleus accumbens
• hyperactivity/sterotypic behaviour
• horses with stereotypies like crib-biting have higher density of opioid receptors in VTA…blocking opioid receptors with chemical can stop crib-biting!
• Dopamine plays a major role in reward-motivated behaviour - most types of reward increase the level of dopamine in the brain

Question 7

Neurophysiology - risk factors that precipitate/ stimulate sterotypies

• main
• housing
• husbandry

Answer 7

• Arousal (=increased levels of β-endorphin opioids)
• Frustration / excitement ( =increased arousal – see above)
• Chronic stress / pain (=increased β-endorphin opioids)
• Acute stress (= direct dopaminergic arousal, feel better, associate behaviour with feeling better)
• Highly palatable foods (=increased levels of β-endorphin opioids)

Housing and management factors

• Limited tactile contact with other horses (mutual grooming)
• Daily free movement (paddock or pasture)
• Low amounts of roughage and high levels of concentrates

Husbandry factors

• eating and anticipation of feed
• weaning
• isolation
• meeting new horses/handlers
• surgury/pain
• reduction in fitness
• increase in work
• change to routine

Question 8

Neurophysiology - risk factors that precipitate/ stimulate sterotypies

• clinical conditions
• foals

Answer 8

• Pain (increased β-endorphin levels – crib biting, box walking)
• Abscesses in feet or teeth (crib biting, wind sucking)
• Other hormonal problems
• Maternal rejection / separation if closely bonded
• Inadequate milk supply, stress increase b-endorphin levels
• Increased protein in creep feed
• Acid indigestion / gastric ulcers

Question 9

Are horses prone to sterotypies

Answer 9

• Never been recorded in free-living wild animals or feral animals
• In captive wild animals frequently recorded (struggle in small environment, not meet all needs)
• Some horses more susceptible than others (genetics)
  i.e. have lower threshold for stimulation
• Twitch test for horses with / susceptible to developing stereotypie
  ~ apply twitch to piece of skin
  ~ animal start to have relase of dopanine
  ~ short term (still for breif period)
  ~ vary impact
• Horses prone to stereotypic behaviours show (twitch):
  ~ Marked startle reaction (head up, muzzle out, ears pricked, wide-eyed, leap forwards) after only 10 mins of applying a twitch
  ~ This is a dopaminergic response = dont need much to create response
  ~ Normal horses require 20 – 30 mins for this reaction to occur
• Horses with stereotypies more often alert and reactive and can be difficult to sedate
• Less sensitive to opioid antagonists (used in sedative drugs)

Question 10

Genetics

Answer 10

• Inherited recessive (but must be exposed to correct stimuli – genetically susceptible)
• An increase in numbers and sensitivity of dopaminergic neurons in mid-brain

Question 11

Control programs

Answer 11

• In absence of direct physical / pathological causes:
  ~ Specific and permanent husbandry changes (+/- concurrent drug therapy?)
  ~ Breeding (approx. 40% of UK equine population genetically predisposed!!) but good at jobs/competitions
  ~ Increase feeding time to 12 – 18 hours a day (e.g. several hay nets spread out)
  ~ Improve social contact - turnout in small groups (3-5 horses), mixed gender and age groups – check if compatible
  Caution excitement / bullying
  ~ Loose yarding housing to give choice of neighbour
  ~ Mirrors, radios etc if must isolate
  ~ Avoid routines – strict routines encourage frustration i.e. feeding times, turn-out times
  ~ Increase fitness levels (decreases basal β-endorphin level) but may get worse to start with as maintain = levels of endorphines even out and stero reduce

Question 12

Sterotypies and feeding

Answer 12

• if less time spent feeding = higher instances and time of abnormal behaviours

Question 13

Reducing sterotypies - traditional methods

Answer 13

• Traditional methods are more likely to increase frustration, increase arousal, increase β-endorphin levels
  E.g. Stable toys may increase frustration and arousal trying to get to toy as often β-endorphin levels increase due to highly palatable foodstuffs used! (glucose)

May lead to poor welfare and increased aggression