Overview of the Issue

Equine veterinarians have a high prevalence of occupational injury and the behaviour of the horse is frequently cited as a cause for these injuries. Equine veterinarians also report frequently having to deal with horses demonstrating unwanted behaviours. These range from behaviours that may be frustrating and prolong the time taken to complete a given task, for example horses that will not stand still or will not load into the trailer to go home, However many behaviours that are can also be dangerous to people working with these horses, for example rearing, striking and kicking out.

Objectives of the Presentation

This presentation will look at how we can incorporate behaviour modification techniques into our everyday practice to deal with difficult horses. It will include multiple video examples of cases to demonstrate these techniques are not only safer and less stressful for everyone involved but also frequently more time efficient.

Shaping

The horse is unlikely to offer the correct behaviour on the first attempt—for example with horse that is already aversive to accepting oral medication they are unlikely to stand still and calmly accept the oral medication so we can reward this behaviour. Instead we need to start with something the horse can easily achieve—using the same example placing the syringe on the cheek instead, so we can reward this behaviour initially and slowly build up to the desired behaviour over several repetitions.

Behaviour Modification Techniques that Will Be Presented

Positive reinforcement—The addition of something pleasant after the desired behaviour.

This makes the horse more likely to repeat the behaviour in the future. Common examples would be food or a scratch on the withers. Giving a horse a quick scratch on the wither when they stand still in an examination room, makes this behaviour more likely to be repeated. The timing of positive reinforcement is vital—it needs to be as close as possible to the desired behaviour. For this reason secondary positive reinforcement is frequently used. For example in clicker training the ‘click’ predicts the food reward and so the click can be times to coincide with the desired behaviour. Clicker training (often combined with negative reinforcement) can be utilised to rapidly train horses to accept ocular or oral medication among many other things.

Negative reinforcement—The removal of an aversive stimulus after a desired behaviour.

Lots of people get negative reinforcement confused with punishment. Try and think of it from the mathematical sense of the word, negative means removal or subtraction of something and reinforcement means to increase the likelihood the horse will repeat the behaviour. A better way to remember this is often removal reinforcement. Pressure is applied to the horse which motivates it to remove the pressure, provided the pressure is released as soon as the desired response is offered the horse will offer that response next time the pressure is applied.

Examples

• If a horse is too hot, they seek shade; if they are thirsty, they drink; if a fly irritates them, they swish their tail. Each time, the horse alters their behaviour to remove the aversive stimulus.
• If you put pressure on the horses head collar (pressure) they should walk forwards and the pressure be released.
• If you raise the horse’s vein and they jerk their head back, the release of contact will be inherently rewarding. However, if you keep your hand in contact with the neck and then remove it as soon as the horse stands still you are instead rewarding the behaviour of standing still. After only a few repetitions the horse will then often stand still and relaxed for venipuncture.

Leading the Horses into Stocks or a Trailer

Make sure you have control of the horse; this may mean leading them in a bridle or chiffeny. Teach the horse to step backwards and forwards lightly using negative reinforcement training (pressure release)

• Backwards—Stroke the horse with the whip on their forelegs to make sure they are not scared of it. Tap the horse on the cannon bone of the leading foreleg until they step backwards with that leg (start off very lightly then get faster and stronger until they move the limb). Do not stop tapping until they step backwards and immediately stop tapping as soon as the limb goes backwards. Once the horse understands backing up from whip taps ask them to step backwards from a light pressure on the lead rope followed by tapping the legs if they don’t step back. The horse will quickly associate the lead rope signal with tapping and start to step back off a light signal
• Forwards—Stroke the horse with the whip on their sides to make sure they are not scared of it. Then tap the horse in the girth region until they offer a step forwards, as soon as the horse steps forwards immediately stop tapping.
• If the horse walks backwards, rears, etc., keep quietly tapping until they offer the correct response of stepping forwards. The horse will quickly learn the only way to stop the tapping is to walk forwards. Once the horse is obedient to step forwards from light tapping give a light cue from the lead rope before you tap. The horse will quickly make the association between the lead rope signal and tapping and begin to lead forwards off a light lead rope signal.

Once the horse is light to will, step backwards and forwards lightly and obediently repeat the process getting closer and closer to the ramp. Once at the ramp ask the horse to step forwards on to it. If they pull backwards keep tapping until they take a single step forwards then stop tapping. If they go to swing the hindquarters away reach forward and tap the hindquarters until they start to move back in the same direction again. Once the horse does step on the ramp stop and give them a rub on the neck or head. Back them off the ramp and then ask for them to step up again. You will find the horse comes further in each time but remember to step them back out fairly frequently to gain their confidence. Once the horse will step all the way in have someone stand inside with a feed bucket. The horse is then walked in each time, is allowed a few mouthfuls of food before being backed out again and the process repeated. Many repetitions consolidates the response and increases the horse’s confidence.

Counter Conditioning

This utilises classical conditioning to replace the horses fear response to a stimulus with one that predicts a positive outcome. A good example would be administration of intramuscular injections into the hindquarters. Initially each time the person thumps the gluteals for the third time, a second person holding the horse should give a small food reward at the same time. After a few repetitions the horse will expect feed on the third ‘thump’. Then the needle can be placed on the third thump without an adverse reaction from the horse.

Approach Conditioning

As flight animals, horses tend to be scared of things that chase them; however, conversely, they rapidly habituate to things they can ‘chase’. So, if you have a horse that is scared of umbrellas, you can lead/ride the horse towards one and, then as they get closer, get a friend to walk away with the umbrella so the horse ends up ‘chasing’ it. In the veterinary context, this technique is more limited but can be utilised for items such as radiography plates, enabling the horse to tolerate them close to their limbs or body.

Stimulus Blending

You can habituate a horse to a scary stimulus by slowly introducing it alongside a stimulus they are confident with. A good example would be for a horse that is scared of fly spray but confident to be hosed off. By hosing the horse and slowly spraying, the horse gets used to the sound; and as the hose pipe is slowly turned down and eventually off, they habituate to the feel of the spray.

Overshadowing

Horses are like men—they can’t multitask! By getting the horse to concentrate on one task, they are unable to be scared of something else and so will become habituated to it. This can be used very successfully to habituate horses to clippers, plastic bags, needles and many more things.

Injecting or Blood Sampling Nervous Horses

The handler should be confident to step the horse backwards or forwards lightly. Approach the horse and give them a scratch at the wither region first. Rub the horse’s neck and work towards the jugular groove. If the horse becomes anxious (he may lift or toss his head, tense his neck, show the whites of his eye), get the handler to step the horse backwards and forwards whilst while (American) the vet keeps rubbing the same spot until he relaxes and wants to stand still. At this point, step away from the horse, and, after a few seconds, repeat, starting from just before the point at which the horse became anxious. This process is broken down into the following steps:

For I.V. injections:

• Rub/scratch the horse’s neck near the wither.
• Rub the horse up and down the jugular groove (this helps desensitise the skin).
• Raise the jugular vein with one hand.
• Press the needle lightly against the jugular vein with the cap on.
• Build up to pressing the needle firmly against the jugular groove with the cap on.
• Inject the horse gently—think of pressing the needle against the skin and gently sliding it into the vein.

For I.M. injections:

• Rub/scratch the horse’s neck near the wither.
• Rub the horse’s neck in the region intended for injection (this helps desensitise the skin).
• Lightly grasp a very small amount of skin.
• Increase the amount of skin twitch and pressure used to hold it each time until you have a handful of skin.
• Wiggle the skin twitch whilst lightly pressing the needle with the cap on against the skin.
• Increase the pressure of the needle with cap on each time until you are pressing it firmly into the neck.
• Gently inject—think of gently wiggling the skin held in the other hand on to the needle.

At each step ensure you step away from the horse each time they become calm and stand still, never step away or remove your hand from the horse if they get anxious—get the handler to step them back and forwards instead. If the horse is getting anxious each time, you are doing too much too soon, step back to a threshold the horse can cope with and remember to step away each time the horse offers relaxation. This will make the horse faster to relax next time.

Summary Including 5 Key “Take Home” Points

1.  Working as an equine veterinarian caries a high risk of occupational injury, and the behaviour of the horse is a frequent cause of these injuries.

2.  Behaviour modification techniques can be utilised to prevent adverse reactions from the horse and are usually faster than traditional restraint methods.

3.  Horses learn primarily through release of pressure. If the contact from the person’s hand is removed (even only momentarily) by jerking their head back or kicking out, the horse will repeat this behaviour.

4.  However, if we can work at a lower threshold for the horse, for example placing the hand on the neck but further away from the jugular, we can then remove the hand when the horse stands still and relaxed, thus rewarding this behaviour instead.

5.  We need to shape behaviours. This means starting off with something that is easily achievable and slowly asking for a bit more with each repetition.

Summary

Working as an equine veterinarian is a potentially dangerous occupation. Equine veterinarians frequently encounter horses exhibiting unwanted and potentially dangerous behaviours. Utilising behaviour modification techniques is safer, less stressful for personnel and the horse, and is generally faster than traditional restraint methods.

References

1.  Pearson, G. (2015) Practical application of equine learning theory, part 1. In Practice. 2015;37:5 251–254. doi:10.1136/inp.h2046.

2.  Pearson, G (2015) Practical application of equine learning theory, part 2. In Practice. 2015;37:6 286–292. doi:10.1136/inp.h2483.

3.  McGreevy, P and McLean, A. (2010) Equitation Science. Wiley-Blackwell, West Sussex, U.K. IBSN 978-1-4051-8905-7.