by Carin A Smith, DVM
The thought of your horse needing surgery is probably not one that comes to mind very often. After all, that happens to other people’s horses. Whether or not your horse ever winds up in the operating room, you’ll still benefit by knowing more about what actually goes on, and how operations are performed in an equine surgery.
Why Do Horses Need Surgery?
A horse may need surgery for many different reasons. Surgery can be done on an emergency or elective basis, and may be performed on any area of the body.
Elective surgery is performed at a convenient time. Just because a surgery is elective, though, doesn’t mean that it can be postponed forever.
The young horse with a bone growth abnormality, the racehorse with a respiratory dysfunction, or the older horse with a tumor requiring removal all require a surgical operation to help them live longer, more productive lives. The most common elective surgery is castration of the stallion.
Emergency surgeries are done the day a problem is diagnosed. These last-minute operations are performed on horses involved in accidents resulting in fractures or extensive wounds that need to be sutured. Emergency procedures are also done for horses with severe colic.
Abdominal (colic) surgery is done to untwist a tangled intestine, to remove an object obstructing the intestinal tract, or occasionally as an exploratory procedure to find the cause of a recurring colic. In newborn foals, abdominal surgery might be done to repair a ruptured urinary bladder.
Orthopedic surgery is frequently aided by the arthroscope. Just as with human orthopedics, arthroscopy allows access to a joint without creating a large incision. This greatly reduces the post-operative recovery period.
Lasers are used more and more often as the laser technology becomes refined and more cost-effective. Lasers are used for cutting and coagulating (stopping bleeding) in many areas of the body.
Where is Surgery Done?
Equine surgery has been performed in a variety of places, ranging from the horse’s own paddock to an elaborately equipped surgical suite. Much of the decision rests on the length and complexity of the surgical procedure, the disposition of the horse, and what facilities are available in the vicinity.
Minor surgeries that can be done quickly with a local anesthetic are often performed at the horse’s stable. Suturing a small cut or removing a minor lump on the horse’s skin are in this group.
Many castrations are also done at the horse owner’s home. Sometimes a short-acting general anesthetic is used, providing just enough time for the routine surgery to be performed. In other cases, the stallion receives a sedative and then local anesthesia and the surgery is done while the animal is standing.
Most other surgical procedures require the facilities, staff, and other benefits of an equine hospital. The horse can be carefully prepared for surgery, including any preoperative blood tests, intravenous fluids, and other special procedures that might be necessary.
For any lengthy elective procedure, the horse is held off of feed for 12 to 24 hours. The absence of a heavy load of food in the horse’s stomach prevents dangerous pressure on the lungs during surgery, helping the horse to breathe more easily while under the effects of anesthesia.
A few hours prior to the surgery, the horse’s mouth is flushed out with water, its hair coat is lightly brushed to remove obvious dirt, and its feet are picked out. The feet are then thoroughly scrubbed to remove any dirt or manure. This prevents transport of large numbers of bacteria into the surgical room.
The horse is given a dose of intravenous anesthetic while in a specially padded room, surrounded by trained personnel who prevent the horse from injuring itself as it falls asleep. Then it’s moved onto a large table especially designed for equine surgery. Often a hydraulic lift system helps raise the horse or tilt its body to an optimal position for the operation.
How is Equine Surgery Performed?
Equine surgery is performed in much the same way as human surgery. The biggest differences involve equipment, which is tailored for use on the horse’s large body.
After the horse is positioned on the surgery table, its feet are covered with rubber gloves or towels. The gas anesthetic machine is hooked up, IV fluids are monitored, and a blood pressure measuring device is attached. Often, blood samples are taken during surgery to monitor how well the horse is responding to anesthesia.
While the anesthetic team is busy at the horse’s head, the surgical prep team sees that the surgical area is closely clipped of all hair. A thorough scrubbing removes all dirt and bacteria, helping to eliminate any chance of infection.
The surgeon and surgical assistants don sterile gowns, caps, masks, and gloves before going to work. A sterile drape is placed around the operating area, and the surgical pack is opened on a conveniently located table. While many of the instruments are the same as those used on people, some are designed especially for horses.
One common question from those not accustomed to surgery concerns the lack of bleeding. Why doesn’t the surgical area bleed profusely when any cut might?
There are two answers to this question. First of all, the surgeon is intimately familiar with the horse’s anatomy and the location of major blood vessels. In spite of that, though, bleeding still occurs through the smaller vessels.
Bleeding is stopped with a combination of pressure, ligation (tying off) of vessels, and the use of lasers or electrocautery: the use of electrical current passed through a fine wire, which is gently touched to the end of a bleeding vessel.
No matter what type of surgery your horse undergoes, some sort of stitches (sutures) will be placed. There are two main types of sutures: self-dissolving (absorbable) and non-absorbable.
Absorbable sutures are placed under the skin, to hold muscle and other tissues in place. These suture materials are designed to hold their strength for a matter of weeks before gradually being degraded by the horse’s body.
Non-absorbable sutures or staples are used to hold skin edges in place. There are several varieties, and each comes in a wide array of sizes and strengths. The type chosen will depend on the area of the horse’s body, presence of infection, and other factors. Non-absorbable sutures are removed approximately two weeks after the surgery.
Next month, we’ll talk about the inherent risks of equine surgery and what to expect after your horse has undergone an operation.
