Sedatives and Sedation in Horses

We routinely sedate horses in practice – after vaccination, it’s probably the most common “routine” job that we do. So, what are we doing? How do the drugs work – and why doesn’t it always happen the same way?

“Sedation – a state of rest or sleep… produced by a sedative drug.”

That’s the dictionary definition, and it makes it sound lovely and simple – give a drug, and the patient goes to sleep. Of course, in reality (as usual with anything equine!) life isn’t that easy…

For those who haven’t seen it before, a sedated horse doesn’t lie down, but their head gets lower and lower, and they may require something to lean on to help them balance. It’s also important to remember that a sedated horse CAN still kick – they’re just much less likely to do so! It often seems that the horse is still more or less aware of what’s going on around them, but they’re too sleepy to care about it. As a result, we’d almost invariably use pain relief and local anaesthetic as well if we’re carrying out a surgical procedure.

There are a wide range of situations in which we like to use sedation. Generally, it’s to make the horse more amenable when something nasty or scary is being done to them. Of course, this varies from horse to horse. There are quite a lot of horses out there that need a sedative before the farrier can trim their feet; and there are others that will allow you to suture up a wound without sedation or even local anaesthetic (not recommended, but occasionally necessary).

Probably the most common reasons we sedate horses for are…

1) Stitching up wounds, to stop the horse wriggling!

2) Tooth rasping, especially when using power rasps and dremels

3) Some surgical operations – for example, many vets prefer to castrate colts under standing sedation, rather than a general anaesthetic. This is because sedation is much safer than a general anaesthetic… On the other hand, the surgery is easier and safer (for the vet, as well as the horse) if the patient is completely “out”, so it comes down to the type of horse and the preference of the vet doing the op.