Using the Five Domains Model to Assess the Adverse Impacts of Husbandry, Veterinary, and Equitation Interventions on Horse Welfare

Simple Summary Using an adaptation of the domain-based welfare assessment model, a panel of horse welfare professionals (with professional expertise in psychology, equitation science, veterinary science, education, welfare, equestrian coaching, advocacy, and community engagement) assessed the perceived harms, if any, resulting from 116 interventions that are commonly applied to horses. Scores for Domain 5 (the integrated mental impact) gathered after extensive discussion during a four-day workshop aligned well with overall impact scores assigned by the same panellists individually before the workshop, although some rankings changed after workshop participation. Domain 4 (Behaviour) had the strongest association with Domain 5, whilst Domain 1 (Nutrition) had the weakest association with Domain 5, implying that the panellists considered commonly applied nutritional interventions to have less of a bearing on subjective mental state than commonly applied behavioural restrictions. The workshop defined each intervention, and stated assumptions around each, resulting in a set of exemplar procedures that could be used in future equine welfare assessments. Abstract The aim of this study was to conduct a series of paper-based exercises in order to assess the negative (adverse) welfare impacts, if any, of common interventions on domestic horses across a broad range of different contexts of equine care and training. An international panel (with professional expertise in psychology, equitation science, veterinary science, education, welfare, equestrian coaching, advocacy, and community engagement; n = 16) met over a four-day period to define and assess these interventions, using an adaptation of the domain-based assessment model. The interventions were considered within 14 contexts: C1 Weaning; C2 Diet; C3 Housing; C4 Foundation training; C5 Ill-health and veterinary interventions (chiefly medical); C6 Ill-health and veterinary interventions (chiefly surgical); C7 Elective procedures; C8 Care procedures; C9 Restraint for management procedures; C10 Road transport; C11 Activity—competition; C12 Activity—work; C13 Activity—breeding females; and C14 Activity—breeding males. Scores on a 1–10 scale for Domain 5 (the mental domain) gathered during the workshop were compared with overall impact scores on a 1–10 scale assigned by the same panellists individually before the workshop. The most severe (median and interquartile range, IQR) impacts within each context were identified during the workshop as: C1 abrupt, individual weaning (10 IQR 1); C2 feeding 100% low-energy concentrate (8 IQR 2.5); C3 indoor tie stalls with no social contact (9 IQR 1.5); C4 both (i) dropping horse with ropes (9 IQR 0.5) and forced flexion (9 IQR 0.5); C5 long-term curative medical treatments (8 IQR 3); C6 major deep intracavity surgery (8.5 IQR 1); C7 castration without veterinary supervision (10 IQR 1); C8 both (i) tongue ties (8 IQR 2.5) and (ii) restrictive nosebands (8 IQR 2.5); C9 ear twitch (8 IQR 1); C10 both (i) individual transport (7.00 IQR 1.5) and group transport with unfamiliar companions (7 IQR 1.5); C11 both (i) jumps racing (8 IQR 2.5) and Western performance (8 IQR 1.5); C12 carriage and haulage work (6 IQR 1.5); C13 wet nurse during transition between foals (7.5 IQR 3.75); and C14 teaser horse (7 IQR 8). Associations between pre-workshop and workshop scores were high, but some rankings changed after workshop participation, particularly relating to breeding practices. Domain 1 had the weakest association with Domain 5. The current article discusses the use of the domain-based model in equine welfare assessment, and offers a series of assumptions within each context that future users of the same approach may make when assessing animal welfare under the categories reported here. It also discusses some limitations in the framework that was used to apply the model.

Pre-workshop assumptions: Good quality pasture; appropriate micronutrients; established diet; access to diet without bullying; ad libitum water Assumptions a Well-managed pasture suitable for horses.
b Acknowledge seasonal change in body condition and potential change in appetite linked with feed availability. c Parasite control through rotational grazing, cross grazing. d Appropriate nutrients, including no micronutrient deficiency. e Established diet (not in transition from one diet to another). f Access to food without bullying.
g Ad libitum water provided.
h No supplements.
i Best practice parasite control (of horse rather than pasture).
j Same assumptions for exercise/status of horse as per housing (healthy horse with healthy teeth).
k Assume fencing/housing is safe.
l Effective preventative medicine program. For concentrates and cut forage: Assume fed from a bucket/bin on the floor; no access to other food sources; fed 2 times/day; energy chiefly from carbohydrate source. Assume energy density of concentrate should be dependent on activity level of horse. For cut forage: Rationed (i.e., periods without access to forage); long-stemmed fibre; reliable supply from same source; correctly stored and free of toxic plants; assume no need to soak. For concentrate only: Short fibres; fed 5 times/day.

Donkeys:
Grass is not suitable; require browsing opportunities. Note: (include below where necessary) Risk of increased incidence and prevalence of oral stereotypies with low proportion of forage and/or high proportion of high-carb diet.

1A
Pasture onlyno choice. DOMAIN 1 Risk of overeating. No opportunity to choose drier food. 2 Impact assessed separately under housing. Duration Continuous for 1 year. Pre-workshop assumptions: Bedding (non-edible) is provided; Ad libitum water and no impact as a result of diet (dealt with under dietary manipulation); Shelter from wind, flies and precipitation is provided; Any conspecifics are part of an established social group; No automatic/operant feeders are being used; No non-feeding environmental enrichment; The enclosure is safe with well-maintained appropriate fencing; Stocking density is adequate for all horses to lie and rise safely. Assumptions a Bedding (non-edible) is provided.
b Ad libitum water is provided (except for outdoor tethering).
c No impact as a result of diet (diet is dealt with under dietary manipulation).
d Any conspecifics are part of an established social group.
e Shelter from wind, flies and precipitation is provided (except for outdoor tethering).
f No non-feeding environmental enrichment is provided.
g No automatic/operant feeders are being used.
h The enclosure is safe with well-maintained, appropriate fencing.
i Stocking density is adequate for all horses to lie in lateral recumbency and rise safely.
j Where yards are considered, horses can access them freely but they offer only limited opportunities for locomotion (i.e., the yards are small (e.g., 10m x 10m)). k Horses are adult, healthy and have opportunity for ridden work/exercise for 1 hour/day. For partial social contact: Assuming that at least one other horse is in visible close proximity and that tactile contact is available (limited mutual grooming); companion horse leaves for 1 hour of work or exercise. For full social contact: One companion only; companion horse leaves for ridden work/exercise. Composition of groups is also important. Assuming that this horse is in a group and is able to fully interact with at least one other horse.

Notes 1
Outdoor -No social contact. Note: If social isolation increases risk of aggression/stereotypies then this may affect management. DOMAIN 1 Impact assessed separately under diet. 2 Opportunity for rotation of paddock will improve outcome. Many horses adaptable/tolerant of very low temperatures. Erosion of paddock due to repetitive tracking. Dust may be an issue in dry climate/mud in wet. Ice may affect drinking behaviour. No opportunity to go indoors. 3 Risk of fencing injuries (low but not zero).
No risk of injuries from conspecifics. Mud feverlinked to wet legs/contact with mud. 4 Constraints on horse-horse interactions; lack of tactile contact, fly prevention, grooming. Increase in flightiness in response to perceived threats (especially for younger horses; unfamiliar environments). Horses will work for access to a paddock with or without social contact. Horses will work for social contact and will work harder to access companionship (direct or over a barrier) than for an empty paddock. This need is not satisfied. Isolated horses show more behavioural indicators of distress than horses in groups but physiological indicators may be contradictory and may depend on horse age and familiarity with environment. Many paddocks are relatively barren. Security is a powerful motivating factorlone outdoor horse must spend more time being vigilant; may affect sleep patterns.

2
Outdoor -Partial social contact. DOMAIN 1 Impact assessed separately under diet.

3
Marginal increase in risk of injury from conspecific. Higher risk of infectious disease through direct contact with conspecific. 4 Robust demand for partial social contact is satisfied. Farm-animal research indicates very high demand for increased space where space is restricted to the point where basic behavioural needs are denied (e.g., turning around and lying down in lateral recumbency). Periods of time when no forage is available/no feeding behaviour. Note: If social isolation increases, risk of aggression/stereotypies, then these behavioural outcomes may affect management.

5
Indoor stable -Partial social contact. Assumptions: One horse in close visual proximity; access through a grille.

DOMAIN 1
Impact assessed separately under diet.

2
As for "Indoor stable -No social contact".

3
As for "Indoor stable -No social contact".

4
Robust demand for partial social contact is satisfied.
No behavioural indicators of distress if horses are compatible. More social behaviour than for "Indoor stable -No social contact". Separation during companion exercise may cause distress for 1 hour/day.

6
Indoor stable -Full social contact. Assumptions: Pair housing in a stable twice the size of a single stable; horses are compatible.

DOMAIN 1
Impact assessed separately under diet.

2
As for "Indoor stable -No social contact".

3
As for "Indoor stable -No social contact".

4
More social behaviour than for "Indoor stable -Partial social contact". Separation during companion exercise for 1 hour/day.

7
Indoor tie stall -No social contact. (e.g., Like Army tie stalls, in a barn environment but without social contact.) DOMAIN 1 Impact assessed separately under diet.

2
No turning around; no view of outside world.
Restricted ability to self-groom. Air hygiene worse than stable as no direct access to outdoors. 3 Restricted muscular activity.

4
Fixed eating height. Same concerns for DOMAIN 4 as in "Indoor stable -No social contact".

8
Indoor tie stall -Partial social contact. Assumptions: Normal Army-style barn with stalls. DOMAIN 1 Impact assessed separately under diet.

2
As for "Indoor tie stall -No social contact".

3
As for "Indoor tie stall -No social contact".

4
Social concerns same as for "Indoor stable -Partial contact".

9
Indoor stable -No social contact with free yard access.

DOMAIN 1
Impact assessed separately under diet. 2 More choice of ambient temperature than when confined to a stable.

3
Fewer risks to health than "Indoor stable -No social contact".

4
Capacity to choose to occupy stable or yard. Same concerns for DOMAIN 4 as in "Indoor stable -No social contact".

10
Indoor stable -Partial social contact with free yard access.

DOMAIN 1
Impact assessed separately under diet.

2
More choice of ambient temperature than in when confined to a stable.

3
Fewer risks to health than "Indoor stable -No social contact".

4
Minimal tactile contact with neighbour. Capacity to choose to occupy stable or yard. Same concerns for DOMAIN 4 as in "Indoor stable -Partial contact".

11
Indoor stable -Full social contact with free yard access. Assumptions: Pair housing in a stable and yard twice size of single stable/yard; compatible horses. DOMAIN 1 Impact assessed separately under diet.

2
More choice of ambient temperature than when confined to a stable.

3
Fewer risks to health than "Indoor stable -No social contact" but more risk of injury than in "Indoor stable -Partial social contact with free yard access". 4 Most demand for social contact is satisfied.
No behavioural indicators of distress if horses are compatible. Separation during companion exercise may cause distress for 1 hour/day. Physical contact increased with opportunities for allo-grooming and other forms of tactile contact) and reduced fear of perceived threats. Relative size of horses matters for allogrooming.

15
Outdoor tethering -No social contact, no shelter. Assumptions: Best standard practice is broad leather collar; chain is 8m (25ft); ability to swivel so chain does not shorten; padding on chain to avoid rubbing; grass to eat; moving once a day; habituated to tethering and collar; water restricted (brought in buckets every 6 hours); access to grazing.

DOMAIN 1
Impact assessed separately under diet.

2
Minimal tactile contact with neighbour.

3
Lack of shelter may be associated with heat stress and sunburn and possibly with increased eye problems. Risk of poisoning. 4 Must learn to drink when water is made available. Lack of ability to escape potential predators.

16
Outdoor tethering: -Partial social contact, no shelter. Assumptions: Visual but not tactile contact.

DOMAIN 1
Impact assessed separately under diet.

2
Less contact than "Outdoor tethering -No social contact, no shelter".

3
As for "Outdoor tethering -No social contact, no shelter".

4
As for "Outdoor tethering -No social contact, no shelter". Duration Up to one1 hour (per day).
Pre-workshop assumptions: Assume positive reinforcement where relevant; interventions are gradually introduced. For all interventions that are repeated on a daily/weekly basis (e.g., training and work), assessment is of one day's training or work. Bit introduction is assumed to be manual (in-hand), rather than the bit being attached to side reins and the horse left unattended. h Habituated to basic handling.

Assumptions
i Horse healthy and has had teeth checked.

Notes
Sandy yard/arena, type of ropes: soft or leather, horse has been trained to lead but not habituated to being tied up.

1
Dropping horse with ropes (using traction to bring a horse to the ground). DOMAIN 1 -

4
Isolation from other horses. Possibility of learned helplessness.
2 Advance and retreat.
Constraint on horse-horse interactions, limited avoidance responses.

3
Round pen training. Assumptions: Chasing horses, using ropes, whips or flags, with or without physical contact being made.
Unfamiliar environment with possibility of dust hazard.

4
Pressure and release training.
Isolation from other horses unless multiple horses are being trained at once.

5
Bit introduction. Assumptions: In-hand with trainer present and observing, rather than unobserved. DOMAIN 1 -

4
Tongue movement, swallowing and chewing may be affected.

3
Risk of some pain to mouth and injuries from bit.
Loss of choice about where to go within enclosure.
Familiar environment, unpredictable event.

3
Injury, falling over, stress may lead to gastric ulceration.

4
Saddle and girth pressures may mimic predatory stimuli.
a. Backing <18 months. Assumptions: Horse has been long reined or driven. DOMAIN 1 -

3
Physical development may not be ready to carry a rider.

4
Saddle and girth pressures may mimic predatory stimuli.

-
3 Physical development may be better able to carry a rider.

10
Forced flexion (using force to flex the horse's neck).
Assumptions: Side-reins attached to girth or surcingle, bit and reins (elastic), forced flexion, at the vertical.
Neck, muscle, swallow, eat or drink, injuries, tail injuries, when tied to tail, falling. 4 Restrict movement and isolation from other horses.
Assumptions: Forelimbs hobbled together, padded or soft leather hobbles, hobbles are the width of normal distance between left and right cannon bones. DOMAIN 1 -

3
Injuries, falling over, running into objects, rope burns, muscle pull, leg injuries.

4
Significant restriction of movement and isolation from other horses. Duration Hours, one-off procedure.
Assumptions a Best practice, surgical intervention will be discussed in another section, familiar location. g Sedation only after primary diagnostic interventions, food would be withheld after sedation.

Notes 1
Medical -One-off, immediately curative. Considered spasmodic colic as primary example.

DOMAIN 1
Test willingness to eat, withhold food (exception for donkeys).

2
No access to edible bedding.

3
Negative impact from veterinary intervention, rectal examination/temperature, some unfamiliar auscultation/palpation of sensitive areas, examination of gums and tongue, nasal gastric tube and paracentesis. 4 Fear, stress, pain from the interventions and physical restraint.

2
Medical -Repeated short-term curative. Considered fresh superficial mid-cannon injury to a forelimb as primary example. DOMAIN 1 -

2
Confinementsee consideration of individual stable with no social contact and no yard access.

4
Confinementsee consideration of individual stable with no social contact and no yard access.

3
Medical -Repeated long-term curative. Considered laminitis as primary example, also discussed equine gastric ulcer syndrome, equine herpes virus, equine influenza, colitis, diarrhoea, hyperlipaemia, minor tendon injuries and weight loss. DOMAIN 1 Food withheld.

2
Confinementsee consideration of individual stable with no social contact and yard access 3 Inducing painfoot lifting, hoof-testers, foot supports, application of therapeutic supports, manipulations for radiography, venepuncture. 4 Restraint, low-grade fear to novel stimulus. Frustrated foraging behaviours. Confinementsee consideration of individual stable with no social contact and yard access.

4
Medical -Prolonged palliative treatment. Considered Sweet Itch/Queensland Itch as primary example, also discussed chronic obstructive pulmonary disease DOMAIN 1 -2 Confinement during dusk and evening in midge season. See consideration of individual Stable with no social contact and no yard access. 3 Venepuncture, skin scrapings/biopsy, intradermal allergy testing.

4
Protective rugs may inhibit some normal behaviours.
Assumptions a Best practice (Veterinarian is up-to-date with continuing professional development and who has experience with this surgery). No financial constraints for owner. Diagnosis is confirmed. b Preoperative analgesia 1 hour before surgery, post-operative analgesia for 5 days (except for hoof abscess). c Diagnosis established (e.g., not considering impact of hoof-testers in locating hoof abscess). Surgical single curative minor. Consideration revolved around Hoof Abscess (Pus in foot) as an example. Non weight bearing on one leg-Hoof abscess-Paring, resection near sensitive tissues (potential for pain but no entry into sensitive tissues), pus is drained, poultice dressing, intravenous non-steroidal anti-inflammatory drugs (NSAID) at time of treatment, oral NSAID pain relief for approximately 4 more days. Wet winter so animal confined in stable after procedure for duration (7 days) of intervention being considered. DOMAIN 1 No withholding of food or water.
2 Confinement in familiar stall/stable for 7 days.

4
Impact of confinementrefer to Housing.

2
Surgical single curative intra-cavity surgery or repeated minor surgery. Consideration revolved around Inguinal Cryptorchid surgery as an example. General Anaesthetic (GA). Protocol as per assumptions above, para-inguinal incision, Dorsal recumbency.
Withholding of water (1 hour) pre-op. Post-operative return to normal feeding after recovery from GA effects (3 hours post standing). Discharge assumed at 7 days, best practice might be sooner.

2
Confined for induction and recovery in unfamiliar environment. Unfamiliar odours.
Surface is unstable. Hospital environment unfamiliar. 3 Residual pain. Risk of injury for recovery. Paralytic ileus. Dysphoria (GA-induced effects). Risk of complications. 4 Frustration.
Poor balance.

4
Surgical major deep intra-cavity surgery-Consideration revolved around Colic Small intestine torsion with resection and anastomosis as an example. No pre-operative starvation, otherwise GA procedure as per assumptions. No exercise or grazing post-operative though some practices do introduce grazing and hand-walking earlier. Assume hospitalisation provides more intensive care than standard hospital stable therefore the environment and non-contact exposure to other animals might be less than other hospital stables. Intensive care stable has drip lines, lights and heaters. DOMAIN

1
Withholding of food and water (24 hours post-operative). More hunger than other surgical interventions. IV fluids to balance hydration.

2
As for other forms of confinement in hospital but with greater restriction of movement due to attachment to drip lines and more frequent interventions for nursing. 3 Indwelling catheter. Stomach tubes for testing reflux three times daily (this may taper off after the first few days once ileus resolves). Risk of ill-health through toxicity of drugs. Risk of laminitis. Risk of hyperlipaemia (e.g., in Highland ponies). Risk of dying (surgery might not be curative). Risk of pain, visceral and from wound itself. 4 More interaction with unfamiliar people. Less ability to lie down to rest and sleep.

Duration
Castrationup to 1 hour, one-off procedure. Identification minutes, one-off procedure except hoof -branding. Other elective procedures minutes, one-off procedure. Pre-workshop assumptions: Sedation and local anaesthetic; no flies (winter); opportunity to move around (to reduce swelling); carried out <1 year of age. For castration without veterinary supervision without post-op analgesia assume no controlled drugs are used.
Assumptions: (Castration). a Sedation, analgesia and local anaesthetic (excluding "Castration without veterinary supervision without post-op analgesia" and wolf tooth removal i Horse is vaccinated against tetanus.
j Surgeon familiar with specific procedure.
k Horse is otherwise healthy, well-cared-for and compliant.
l Post-operative treatment and monitoring: 6-12hours in clean box. Post-operative analgesia for 5 days.
m Assessments are for single intervention (i.e., first time, no repeats).

Assumptions: (Identification)
a Best practice.
Assumptions: (Other elective procedures) a Best practice.
b Carried out at <1 year of age.
Duration of assessment for 7 days post-op.

Notes (record any variations to duration here)
1 Standing castration with post-op analgesia.

Assumptions:
Not considering impact of loss of testicles. DOMAIN 1 -

3
Risks of infection, eventration and haemorrhage (1-in-10 incidence across all complications). Pain during and after procedure. Inflammation. 4 Restraint. Delay before return to normal behaviour. Inhibition of some behaviours due to pain.

3
As for "Standing castration with post-op analgesia".

4
As for "Standing castration with post-op analgesia" but expect increased latency to return to normal behaviour.

3
Castration with general anaesthetic and post-op analgesia. Assumption: Performed within home environment. No sutures. 20m GA.
(Assessed relative to "Standing castration with post-op analgesia") DOMAIN 1 -2 -3 As for "Standing castration with post-op analgesia" but increased risk of injury during induction (with the horse being ataxic when going down). Myopathy during GA. Increased risk injury in post-GA recovery. Slightly increased risk of contamination leading to local infection. Risk of intestinal stasis. 4 Latency to return to normal behaviour in 24 hours or longer. Risk of sedative wearing off before ketamine.

4
Castration with general anaesthetic but without post-op analgesia. DOMAIN 1 -

3
As for "Castration with general anaesthetic with post-op analgesia".

4
As for "Castration with general anaesthetic with post-op analgesia".

3
Crushing of tissues. Neurological wind-up. Increased risk of injury during restraint and escape attempts. 4 Severe hyperalgesia.

6
Hot branding. Assumptions: Two locations at least three possible for symbols. Location assessed=off-side shoulder (see Horse Sense). Sensitivity may be slightly lower on the rump than on the shoulder. After weaning at 5-8 months of age. No pain relief. DOMAIN 1 -

4
Behavioural reactions consistent with pain and distress during the operation. Local hyperalgesia for 24hrs. Increased dermal sensitivity away from branding site.
Local inflammation, still some after 24hrs. Inflammation at 7days. Scarring. 4 Less behavioural reaction consistent with pain and distress than for hot branding.

8
Hoof branding. Assumptions: Not near sensitive tissue. More than 4 numbers applied in the brand. Duration of procedure = Few seconds.

3
Secondary risk that "hoof can chip away".
Assumptions: Clipping of hair-coat; superficial and deep local analgesia. Chip introduced into nuchal ligament via a 12-gauge needle.
Performed at approximately 6 months of age. Behavioural reaction to chip insertion. LA tolerated reasonably well (NdB pers. obs). No evidence identified by group of behavioural effect after 24 hours unless complications.

12
Caslick's procedure. Assumptions: The procedure creates an elective wound that repairs by primary intention. Fine strip of vulval skin above pelvic shelf is removed and the exposed tissues are sutured together.
(NB at some point sutured tissues will need to be opened up again if bredi.e. a further incision).
(If bred, Caslick's is likely to be repeated, with breeding cycle, for rest of breeding life). DOMAIN 1 -

4
Some difficulty urinatingincreased frequency, low volume urination/intermittent stream for up to 4 days.

13
Modified Forsell's procedure (= removal of 2cm of motor nerves rather than muscles, as in the original Forsell's procedure).
Assumptions: Crib-biting horse. Operation may be 10 minutes in duration for both sides of the neck. NB No longer recommended (i.e., difficult to define best practice).

DOMAIN 1
Decreased food intake if impact on ingestive behaviour and possible on the consummatory aspect of crib-biting itself.

3
Low risk of neuroma.

4
Preventing a motivated behaviour (at least for 7days).
Most recent studies suggest that no impact on performance of crib-biting. Interference with feeding behaviour.

DOMAIN 1
Post-operative mild/moderate reduction in food intake.

3
Wound and some post-operative inflammation.

4
Some difficulty in swallowing.

15
Wolf teeth removal. Assumptions: No analgesia. Assessment based on the size of tooth expected in a 1-year-old. DOMAIN 1 Some reduction in food intake. Some difficulty in urinating. e Horse is well hydrated and well fed prior to restraint and commencement of procedure.

-
f Procedure is carried out by competent technician.

Notes 1
Whisker removal. Assumptions: Whiskers are cut (not pulled out) from around muzzle only. Note: Banned in some countries to remove hairs with protective/sensory function.
Possible some proprioceptive deficits and reduced spatial awareness during grazing due to removal of sensory hairs.

2
Challenge to thermal regulation. Noise of clippers during procedure. 3 Potential increased risk of injury during clipping. Potential increased risk of injury post-clipping. Risk of burns, cuts from clipping procedure. 4 Horse is more sensitive to tactile stimulation. Lack of ability to self-regulate thermal comfort/rugging.

3
Risk of traumatic injury to soft tissue and joints.

4
Aversive procedurepotential for horse to become head/mouth shy. Cannot close mouth and swallow effectively during procedure.
14 Horse-walking machines. Increased risk of abrasion and some types of skin infection/infestation (lice). Increased risk of injury (e.g., when straps/rugs become caught on fencing). 4 Reduced capacity for allogrooming. Lack of ability to self-regulate thermal comfort.
Assumptions: Standard practice as per (see p.29 Horse Sense). Observer makes regular checks. DOMAIN 1 -

2
Challenge to thermal regulation. Challenge to physical comfort.

3
Small risk of injury during placement of hood if horse panics. Increased risk of abrasion and some types of skin infection/infestation (lice). Increased risk of injury (e.g., when hood becomes caught on fencing). 4 Risk of altered response from other horses due to changed appearance. Reduced ability for allogrooming, self-grooming and possibly fly-swatting. Lack of ability to self-regulate thermal comfort.

17
Grazing muzzles. Assumptions: Fits correctly; quick release if caught; horse can eat limited quantities of forage (trickle grazing); drink as normal.

4
Restriction on grazing and browsing including limits on prehension.
Restriction on allogrooming and self-grooming. Some horses rub or paw at muzzle. Possible frustration and reduced oral satisfaction from the limit on grazing.

18
Collars for oral windsuckers/crib-biters. Assumptions: Design has rigid structure to accommodate the trachea; no electric shock. Risk of reduced swallowing behaviour. Frustration from reduction in capacity to crib-bite without addressing cause.

20
Tongue-ties. Assumptions: Tie is used during racing (flat, jumps, harness) track-work and race days; tightened to prevent tongue moving. Duration up to one hour. DOMAIN 1 -

3
Dry tongue and dry oral anatomy distal to the tongue tie. Tongue trauma/lacerations. Potential for reduced vascular perfusion of localised tissues. Potential for damage to hyoid bones. 4 Reduced capacity to swallow. Cannot eat or drink.

3
Risk of some tissue damage through killing worms.

4
Potential for head shyness. Behaviours indicative of unpalatability.

23
Pulling the mane and tail (manual depilation for cosmetic purposes). Assumptions: Pulling whole mane and tail at one time; horse is warm; week before competition; hay net provided (see p.34 Horse Sense). Duration 2 hours. DOMAIN 1 -

Localised pain. Large individual variation in behavioural responses.
Less effective swishing to remove flies after procedure.

39
Sheath cleaning. Assumptions: Conducted on gelding; no pre-existing infection/inflammation. Using proprietary sheath-cleaning product according to label instructions. DOMAIN 1 -

3
Risk of introducing infections. Allow infections to establish due to damage to microflora. Risk of trauma from removal of inspissated smegma from urethral fossa. 4 -
Assumptions: (See p.21 Horse Sense); trimming procedure and regularity as for shoeing; permanently barefoot horse. Note: There are many different approaches to trimming. DOMAIN 1 -

3
Mild changes to angulation and length of hoof. Sole close to ground after trimming; exposure to potential bruising. 4 Movement restricted by leg lifting.

44
Shoeingcold. Some horses may be "foot sore". Loss of frog contact. All forms of restraint restrict movement/placing a high cost on movement. Potential for ear -shy behaviour (short and long term). Threshold for compliance may be reached (acquiescence turns to violent behaviour).

2
Nose twitch. Duration best practice maximum of 15 minutes (prior to arousal). DOMAIN 1 -

3
Initial pain may lead to increase in endogenous endorphins.

4
Provides physical control as well as behavioural restriction.

3
Less physical damage than ear/nose twitches.

4
Note: Practitioners state that it has a distracting effect thus allowing other minor painful procedures to be conducted. Potential "overshadowing". Unlikely to be pain-free.

4
Chifney bit, also known as an "inverted port" or 'stallion bit". Best standard practice is to just vibrate and release, rather than pull/tug; but the absolute absence of any pulling or tugging seems unlikely. Inability to escape threats from unfamiliar conspecifics. Increased potential for indirect aggressive behaviour from unfamiliar neighbours (food competition). None of the general stress reduction due to presence of familiar conspecifics.

4
Groupwith familiar companionspenned as a group. Assumptions: Forage provided on floor prior to loading; not feral/wild (e.g., Shire horses, stock horses, rodeo horses).

DOMAIN 1
Restriction on water intake. Competition for food resource leading to no access to food. 2 Higher ammonia concentrations relative to individual transportation. Increased space/ability to move around may be accompanied by increased ability to slip.

3
Increased risk of injury from other horses; movement of vehicle may cause injuries. Attempts to balance and adjust position may increase injury rate. 4 Full social contact. Competition for food resource. General stress reduction due to presence of familiar conspecifics. Duration Hours (assessment is of the equivalent of one day's training or competition).
Pre-workshop assumptions: Assume horses are physiologically and behaviourally fit-for-purpose and level of activity; no riders >15% horse's bodyweight; rules (such as they are) are being observed and that aversive stimuli are being used according to the ISES Position Statement on Aversive Stimuli; assume horses are not wearing tongue ties or restrictive nosebands; duration of activity/day is adequate for fitness and regular competition for that activity. Duration is in hours and the Frequency is at least once. Assumptions a Horses are physiologically and behaviourally fit-for-purpose and for the level of activity.
b Assessment is done for a trained horse on a single day of competition.
c Rules (such as they are) are being observed. d All activities are assumed to be conducted at affiliated level. e Duration of activity/day is adequate for fitness and regular competition for that activity. f Competitors in each given sport are reasonably competent in application of negative reinforcement.
g Assessment does not include housing/nutrition/transport conditions. **Note: Different sports have very different dietary regimes and housing.

DOMAIN 1
Horse may have limited control over feeding and drinking times. Metabolic disorders may arise due to chronic overfeeding, loss of thermal control and possible loss of proprioception due to rugging. 4 Challenges include restraint, neophobia, thermo-regulatory challenges, confusion, unpredictable signals, horse conflicted, horses being chased, intimidation and excessive lungeing. 3 Showingridden. Note: Not within rules but note documented use of inflammatory agents to induce elevated movements, use of weighted shoes to affect gait and irritants to affect tail height.

DOMAIN 1
Horse may have limited control over feeding and drinking times.

2
As above, for showing in-hand.

3
Aversive stimuli may be imposed via bits, spurs and whips.

4
Eventingcompetition. Assumptions: As for dressage, plus kit for cross-country phase, including boots and martingales.

DOMAIN 1
Intermittent feeding and drinking opportunities.

2
As above, for showing in-hand.

3
Greater physical demand than during training, risk of over-heating, no control over start time to suit weather conditions such as ambient temperature. As for dressage, but more varied activity. Risk of more severe injury is much higher than in dressage but the risk of repetitive strain injury is lower. 4 Variety of training devices used during competition. Punishment can be common (e.g., when horse refuses). Continually exposed to novel stimuli, purposeful exposure to challenging situations (e.g., light/dark contrast, large jumps and ditches).
Assumptions: Appropriate footing substrate for competition, physical check by steward, veterinary inspection at highest levels, some control on use of medications; same rider, no restrictions on rider weight, likely to use spurs, dressage whip, double bridle (curb bit) optional from elementary level but mandatory at advanced level.

DOMAIN 1
Horse may have limited control over feeding and drinking times.

2
As above, for showing in-hand.

3
Repeated performance of similar movements could affect musculoskeletal health, performance of non-natural postures (hyper-flexion) could affect musculoskeletal and respiratory health. Exposure to dust from arena substrates. Potential for development of gait abnormalities including bridle lameness. High bit pressures may be applied relentlessly. Prevalence of gastric ulcers, may be high but is probably confounded with housing practices. 4 Rider more aroused than during training thus increasing the risk of altered signalling and responses. Note: Prevalence of stereotypies may be high but is probably confounded with housing practices. High degree of concentration required to respond to simultaneous/multiple signalsimpact not yet known. Punishment can be common (e.g., when horse does not want to enter ring).

Endurance.
Assumptions: Competition. No spurs, no whips >75cm, no whips in last phase of race, pre-ride vetting, 7 years-of-age minimum, most events will be 65-80km, but occasionally (3 times/year) 160km, horses are crewed, some rider variation (possible national variation in this).

DOMAIN 1
Horse may have limited control over feeding and drinking times.

2
As above, for showing in-hand. Terrain may be very variable and often stony.

9
Trail riding. Assumptions: Hacking on own horse, up to 1 hour, no rules, unlikely to be supervised, very variable tack. DOMAIN 1 -

2
Very variable, unpredictable (e.g., with exposure to dogs and traffic), riders may be inexperienced.

12
Western performance (e.g., reining). Assumptions: Competitiontraining can start at <2 years of age, competing at 3 years of age, rules according to FEI, severe bits and spurs but no whips, romal reins (leather rein with free loose end originally used in moving cattle but sometimes used to hit horse) may be used. Tests are short. DOMAIN 1 -

2
As above, for showing in-hand. Deep arena substrate.

3
Musculoskeletal challenges resulting from high-speed acceleration, deceleration, turns, risk of injury from severe bits and sudden stops. Sharp rein pulls may be used and severe spurs with rowels.

13
Community clubs (pony club, riding club). Assumptions: Riders training and competing at unaffiliated level, show-jumping, cross-country and dressage. Horse must be 4 years old, rule books variable. No veterinary inspections or defined policies. DOMAIN 1 -

2
As above, for showing in-hand. Tack and equipment very variable, volunteer event managers. 3 Musculoskeletal challenges due to inexperienced riders, infectious disease risk, biosecurity risks, transport effects on health, injury risks, fatigue. (? Perception among some that water deprivation might calm horse). 4 Horse has limited control over feeding and drinking times, neophobia, thermoregulatory challenges, confusion and unpredictable signals. Punishment can be common (e.g., when horse refuses).