Rural Veterinary Experience, Teaching, and Service
An introduction to the equine field castration.
We expect all participants of the clinic to have prepared. This includes;
- Read the chapter on equine castration in Turner and McIlwraith “Techniques in Large Animal Surgery”.
- Practiced the modified millers knot
- Memorize the steps to a routine castration listed below. You should say these steps, out loud or in your head, as you castrate each horse. This will help to ensure that you do not forget any step in the process (this tends to happen after you start to get comfortable with the process)
If you do not know the steps to a castration, should you be doing one?
- Work days tend to be long. Individual or group inefficiency and unpreparedness will lengthen the day. This results directly and indirectly in a loss of teaching time as there is
Less time to rest/recover Less time to round – without rounds the learning experience is incomplete.
Keep in mind that the staff may be on the road for 2 months. Cumulative lost rest is a significant issue for us.
- DO NOT sit or chat if all equipment and supplies are not ready for the next procedure.
- Students will be assigned to a team. The team may rotate working with different doctors. You should communicate within and between teams so that everyone is ready and plays their own position.
- Maintain all necessary equipment and drugs so that they are easily available, clearly labeled, and easy to move (this is particularly important in an emergency, and you never know what you will need). DO NOT carry supplies in pockets (they will fall out when you bend over) or in an arm load (you will drop them). We have caddies, buckets, bucket buddies, and toolboxes for this purpose Blades, needles and syringes must be put in the caddy immediately after use to avoid their getting lost.
- Start and stay prepared. Each evening the group is expected to prepare for the following day. Volunteers are responsible for adequately preparing for the day’s work. check that there are sufficient:
- Vaccines-- tetanus, and rabies
- The equine surgery box-fully stocked
- Filled carboys, collapsible water jugs or buckets lined with garbage bags, twisted shut above the water level
Anesthesia is discussed in another section
- All team members should be prepared to perform their assigned tasks prior to the patient becoming
recumbent. You should always know your assigned task for the current procedure, and for the next.
- Once the patient is recumbent and adequately anesthetized the rest of team should move quickly to complete their assigned task/tasks as efficiently as possible.
- Do not rush the patient. Wait until they are fully relaxed to proceed. The upper leg should be resting on the ground.
- Everyone involved in the process must remain on the horses back side, which is the side away from the hooves.
- The exception to this is if you are doing a procedure involving the leg or foot.
To increase exposure, minimize stimulation caused by manipulating the testi and stripping the cord, and paralyze the cremaster and tunic muscles. Increased exposure and muscle paralysis are also useful in the case of post operative bleeding.
- Use a 35 cc syringe filled with block (cabocaine or lidocaine) and an18 gauge needle.
- Inject 10 mls block into the each spermatic cord. Isolate and grasp the spermatic cord firmly. Insert the needle where the cord rolls over your thumb and index finger, aspirate to insure you’re not in a vessel, and inject 10 ml carbocaine into each cord. To work your needle MUST be in the cord. The block will not migrate across the tunic.
- Inject directly into the center of each testis until you feel them become turgid (full). This is easier to learn, but takes more time and anesthetic, as it must migrate up the cord. If the team is efficient, the castration may be completed before the anesthetic has taken effect.
- Slide the needle under the skin and inject 5-7 mls of block where you plan to incise.
- Replace the needle on the carbocaine syringe and refill.
NEVER SET A SYRINGE DOWN WITHOUT A NEEDLE!! Once you do the syringe must be considered contaminated and discarded. Do not remove the needle unless you are holding the replacement needle and are ready to place it.
NOTE: Maintain correct body position as the testis is injected.
Always remain in contact with the patient’s leg
At this point the surgeon can begin. The support team
will continue as indicated below.
5.Check the record. Using your note cards, assess and record;
6. Administer and record
- PPG (if you are really efficient, you can administer this during the prep. Otherwise, wait until the emasculators are on and the leg rope is released.
- Antitoxin (ONLY IF INDICATED BY PATIENT HISTORY)
- Always verify what is in the syringe prior to administration. Do not administer any drug if you do not fully understand what its function is, and how much the patient should receive.
- State clearly and audibly what you are administering and by what route as you do so. Each step performed during a team effort should be stated clearly in a loud enough voice for the entire team to hear.
- This will prevent patients from receiving the same treatment twice and will allow the scribe to record all pertinent information.
NOTE: All team members should be familiar with all tasks and supplies necessary to complete the castration process. Never stand idle if all equipment and supplies are not ready for the next patient.
1.Prepare for surgery prior to the patient becoming recumbent. Check that you have; a. Surgery bucket filled 1/3 to ½ way with water and nolvasan or betadine b.Gloves c. Blade d.Suture (always be prepared to ligate. Don’t open the suture, someone can pass it to you, but
verify that it is available)
e.Emasculators f. Needle drivers g.Scissors h.Large clamp (bronchial clamp or Ochsners)
Equipment Behind Leg, In Reach of Surgeon
9.Reduce the tension on the leg rope and a.Allow the leg to drop almost to the lower limb. Allowing the leg to drop to the ground may
inadvertently release the leg from the rope.
b.Wait •One minute per year of age 10.Remove the emasculators a.Raise the leg b.Open the emasculators •Perpendicular to the cord 11.Check for bleeding as the cord slips back into the patient 12.Trim any tissue that will hang down from the incision after the patient stands up 13.Clean the scrotum 14.Remove the leg rope 15.Pull the down forelimb forward. This will prevent the radial nerve from falling asleep 16.Pick up gauze etc 17.Check the record 18.Prepare for the next patient
Splitting the Cord
At times the size of the cord will necessitate emasculating it in two crushes. This method provides a better crush and requires less hand strength, as the tunic is removed separately. The emasculators do not need to be in place for much time, as the quality of the crush is much higher.
Follow the steps for a routine castration. Once the cord has been stripped;
This is a well stripped cord. This cord will be much easier to crush than a poorly stripped cord
Hold the emasculators close to the neck during placement and close only until they begin to bite the cord.
Lie the testis down and use both hands to close the emasculators completely in one smooth crush
7.Stretch the incision a.Place your index fingers or thumbs in the front and back of the incision b.Stretch the incision until you feel it tear. You must
mean this when you do it.
8. Repeat the process on the up testis.
REMOVING THE MEDIAN RAPHE
Removing the median raphe is a technique used by some practitioners. This step is not frequently used on RVETS clinics, and can take the place of stretching the incision.
1.Apply traction the median raphe using your non dominant hand.
2.Avoid any large vessels. 3.Excise the raphe using a pair of scissors.
Repetition, not force, will break down the fascia. Gauze is unnecessary. Simply grasp the cord firmly and repeatedly stroke until the fascia breaks down.
1.Using a pair of blunt tipped scissors, extend the hole you created for your finger hold as far down
the cord as your scissors can easily reach.
2.Place a clamp on the tunic to prevent losing control of it. If lost, the retained tunic can become the
focus of a scirus cord.
Place a clamp on the tunic
Use blunt tipped scissors to cut the tunic open
The details of what you do are important. They make the difference in every task you undertake. They are the difference between fumbling through a procedure, and looking confident and competent. If you pay attention to the minutia, the larger issues will take care of themselves.
Check out the Donkey Welfare Symposium website and visit us at the symposium for a great educational opportunity, CE credits available