Скачать или смотреть Why does my horse..... SHAKE HIS HEAD?

Head shaking

As you look woefully at your beloved horse child, you can draw only one conclusion: clearly he has joined a death metal band and is rocking away to a tune he has stuck in his head. After all, what else could explain this enthusiastic whiplash-inducing head shaking behaviour?

Head shaking is a pretty disturbing behaviour, and some horses can take it to such an extreme that they become debilitated by it. For many years head shaking was considered a behavioural issue, but nowadays it's recognised as a medical one. It should be noted that there is a difference between head shaking and head bobbing, although the two overlap in many ways and make it quite complicated to tell the difference. Head bobbing normally accompanies other stress related behaviours like pawing or weaving, most often during high anxiety times such as feeding time. Although there are some similarities between the two behaviours, true head shaking occurs in circumstances that can't possibly be linked to stress, anticipation or anxiety. Head shaking horses sometimes rub their faces against their legs or strike their faces with their front legs. To muddy the waters even further, they sometimes stop when they change venue, making it look very much like a behavioural issue. These annoying complications are the reason why it wasn't considered a medical issue until fairly recently.

When we look at medical reasons for head shaking in horses we come up with a list as long as your arm. There are innocent reasons, like the horse having ticks in his ears or a piece of grass lodged in his nose. These are easy to fix and will quickly alleviate the headache your horse probably has. Most owners have the wherewithal to check their horses ears, eyes, and noses for any sign of obvious discomfort (much to the disgruntlement of the horse). Once we have satisfied ourselves that we really can't see anything, we normally get a vet on board to start doing some investigating. They are looking (and hoping to find) something straightforward like a painful tooth, sinusitis, or an obstruction higher up in the nostrils. In this pursuit they will check the teeth properly for signs of pain or infection, and possibly do an endoscope to check out the nasal cavity and airways to make sure all is clear. Once all the obvious surface stuff has been cleared, the investigation goes into a whole new direction.

From here the reasons for head shaking start to become a bit more ominous. There are allergies, whether to pollen, grasses, dust or other free floating particles. This is the case for about 60% of head shakers, and in about a quarter of horses a nose net reduces the shaking up to 75%. Another reason for head shaking is light sensitivity, that is, a reaction to strong sunlight. These horses do well tucked away out of direct sunlight during the brightest hours of the day. Then there are potential dietary deficiencies leading to tingling of the nerves in the face, although academic sources still lack enough objective evidence of this, some owners swear by it. Lastly, if all else has been tried, tested and failed, the horse is presumed to have a condition known as trigeminal- mediated head shaking. It's as awful as it sounds.

Trigeminal-mediated head shaking is described as a sharp, shooting nerve pain in the horses face. It is the result of a misfire of the trigeminal nerve in the horses face that sensitizes the areas around the eyes, nose and teeth. Essentially this nerve becomes hyper sensitive, causing severe pain in the face when there is no appropriate stimulus. It is very difficult to definitively diagnose the illness because it doesn't necessarily respond to nerve blocks and can change in severity according to the season or change of location. It is also challenging to treat because it doesn't respond well to traditional neuropathic pain medication.

So what can owners of these horses do? There have been some positive results with a combination of anti-histamines and anti-epileptics, but the results haven't been conclusive. Surgical interventions have been tried but reported to have severe negative side effects and are not recommended. For horses with the illness a potentially viable treatment option is electroacupuncture, which stimulates a portion of the nerve and apparently treats the pain.

It might be hard to understand just how much pain our horses are in when they engage in devastating head shaking, and the treatment options are frustratingly inconclusive. However we owe it to our horses to remain patient when their behaviour feels overwhelming to us, and do our best to find the root cause of the behaviour so we can make their lives, and ours, a whole lot more peaceful.