A speculum is an instrument used to hold open some type of body cavity. In the case of horses, a speculum is typically used to hold the animal’s mouth open so that its teeth can be worked on. The equine speculum serves two purposes. First, it helps the caretaker access the necessary parts of the horse’s mouth to treat injuries and file teeth. Second, it minimizes the chance that the horse will be able to harm the person treating it, since it is not able to bite while the equine speculum is in place.
When using an equine speculum, it is important to be careful not to damage the horse’s mouth or jaws. Because the speculum can be used to force the mouth open, it is possible to crack teeth or injure the horse’s jaw. Gentle handling needs to be a priority, and care in deciding how far the horse’s mouth must be forced open is important as well.
An equine speculum comes in many different forms, but there are a few types that are most commonly used. The first is a simple set of rubber wedges that is forced in place far back in the horse’s mouth, preventing it from closing. These wedges are good because they are not likely to injure the horse, but they can be difficult to use since placing the wedges requires a certain amount of cooperation from the animal.
Another popular equine speculum is an instrument that resembles a halter, but can be ratcheted open once it is slipped into the horse’s mouth. For horses used to wearing a bit and bridle this tool is not frightening and the horse will generally not resist the placement of the speculum, since it feels similar to equipment it is used to wearing. A strap over the nose and around the back of the horse’s head holds everything in place so that the horse is not able to dislodge the speculum from its mouth once it is on.
The final type of equine speculum is a simple device that can be inserted into the horse’s mouth to hold it open, but there are no external parts. Such a tool usually has a rope attached so that the horse cannot swallow or choke on the device. Some of these use a large spring to hold the mouth open, while other types fit over the back teeth and can be propped open, usually with some type of ratcheting device so that they can be used to force the horse’s mouth open.