Preparing to Anesthetize a Giraffe in a Confined Area
American Association of Zoo Veterinarians Conference 2012
Nadine Lamberski, DVM, DACZM; Andy Blue
San Diego Zoo’s Wild Animal Park, Escondido, CA, USA

Reprinted with permission from the International Association of Giraffe Care Professionals.

Abstract

Planning and preparation are key components to a successful giraffe anesthesia. Since no two facilities will be exactly the same, it is important to understand the basic requirements of the work area as well as things to avoid. The substrate should create suitable traction to ensure adequate footing. It should also be thick enough to cushion the animal when it falls. The area should be large enough to accommodate the animal in lateral recumbency and to allow people and equipment to move safely around the animal. Two exits are desirable to prevent personnel from becoming trapped in the enclosure with the animal. Hazards such as hayracks and concrete drinkers should be removed or padded. Eight to ten people are necessary to position, roll, or move the giraffe as needed. Personnel should have duties assigned in advance to prevent chaos and to facilitate working simultaneously to keep anesthesia time to a minimum. Animals should be fasted when possible. During anesthetic induction, the animal may fall over backwards, hit its head against the wall, splay, or even wedge itself into a corner and thus is unable to fall. Staff should be prepared to push, pull, or trip the animal (using ropes) to facilitate recumbency. Reducing stall size with hay bales and lining the walls with a few rows of hay bales may reduce trauma. A neck board is used to support the head and neck at a 45–60-degree angle. The neck must be kept flat and any kinks in the cervical vertebrae should be quickly remedied. The head should be maintained above the level of the rumen and should be supported immediately once the animal goes down. Problems during recovery are similar to induction. Giraffe usually stand with the rear limbs first and they do need enough room to rock and roll sternal. Ropes and straps may be useful to prevent the animal from going over backwards until it regains its balance.

Planning

Planning and preparation are key components to a successful giraffe anesthesia. If this is the first time a giraffe anesthesia is performed at a given facility, planning should commence well in advance and the procedure reviewed multiple times. Essential personnel include, but are not limited to, animal managers, animal care staff, veterinarians, veterinary technicians, and facility and maintenance personnel.

  • Review the facilities.
  • Review personnel safety (escape routes, working around the animal, accidental narcotic exposure).
  • Review goals of the procedure and timeline.
  • Discuss the logistics of the procedure and anticipate problems. It is helpful to review scenarios of what can go wrong and how the staff should respond. This may help to prevent problems but also prepares the staff and generates an emergency equipment list.
  • Identify roles and establish the chain of command. Personnel should have duties assigned in advance to prevent chaos and to facilitate working simultaneously to minimize anesthesia time.
  • Solicit input and address questions and concerns.

Enclosure Size and Shape

Carefully evaluate the options for where the procedure could take place. Indoors or outdoors? Corral or stall? What’s the weather going to be like? Is there adequate lighting? Is there vehicle access? Is there electricity? What are the walls of the area made of? How much access is there to the animal? Since no two facilities will be exactly the same, it is important to understand the basic requirements of the work area as well as things to avoid. The area should be large enough (at least 20 feet in one direction) to accommodate the animal in lateral recumbency and to allow people and equipment to move safely around the animal. If an area seems too large, the size and shape can be altered using stacked hay bales, rubber pads or mats, or even mattresses. Giraffe can flip over backwards, and this can be fatal. Consideration should be given as to how to break the fall and prevent the head from striking a hard surface. Reducing stall size with hay bales and lining the walls with a few rows of hay bales is one option as noted above. Ideally, two exits should be available to prevent a person from becoming trapped in the stall with the animal. It is preferable to have access to the head via catwalks. Alternatively, scaffolding or ladders can be used to access the head of the giraffe if necessary. Solid or chain link walls are acceptable. Horizontal bars alone can be problematic. Walls should extend to the ceiling or at least be shoulder height. Areas with moats should not be used unless a temporary wall can be created to prevent the animal from falling into the moat. The temporary wall needs to be strong enough to stay in place against the weight of the giraffe.

Substrate

The substrate should create suitable traction to ensure adequate footing that prevents the animal from slipping. It should also be thick enough to cushion the animal when it falls and while lying in lateral recumbency. Playground sand works well. The chosen substrate should produce a minimum amount of dust. If this cannot be avoided, the surface can be lightly sprayed with water to reduce dust. Additional substrate can be used to even out the stall surface and correct and slopes.

Enclosure Hazards

Hazards such as hayracks and concrete drinkers should be removed or padded. Cover any sharp objects along the walls and carefully scan and cover exposed chain link if there are areas that may cause injury.

Equipment

Organize medical equipment so it can be moved easily in and out of the stall. Working out of crates or grips will limit litter in the stall and facilitate the rapid clearing of the stall. Vehicles should be loaded such that emergency equipment and supplies are within easy reach. Nonmedical equipment needs include:

  • 4 nylon straps at least three inches wide, 20 feet long
  • 4 lariats or one-inch cotton ropes to restrain legs
  • 4 two-inch straps to hold the head and neck to neck board (optional)
  • 4-inch-thick pads
  • Large rubber inner tubes (optional if additional padding needed)
  • 30 feet long, two-inch cotton rope
  • Padded board or ladder to support the neck (8 feet long for an adult)
  • 8-foot step ladder
  • Generator
  • Extension cords
  • Portable lights
  • Hay bales to support neck board (3–5)
  • Feed bags or pads for support of limbs during hoof trimming
  • 10-foot length of PVC pipe or bamboo for giraffe manipulation
  • Winch
  • Access to skip loader or Bobcat
  • Eye drape or cover
  • Ear plugs
  • Blankets/towels
  • Oxygen tank and accessories
  • If using pulley system through the roof:
    • Halter
    • Collar with clips
    • 2 one-inch cotton guide ropes, 40 feet long
    • Pulley in ceiling with snatch block

Herd Management

Where will the other animals be housed immediately prior to and during the procedure? When will the target animal be separated from the herd? It is best to keep the daily routine as normal as possible to reduce stress.

Fasting Instructions

Animals should be fasted when possible to reduce the risk of regurgitation. It is most important to restrict food that is easily fermentable such as grain and pellets for 48 hours. Hay is okay to feed as it might help to create a mat of fiber on the rumen surface. Water should be withheld for 12–24 hours (weather dependent).

Anesthetic Induction

Much like flying a plane, anesthetic induction and recovery are the two most critical times during anesthesia. Possible scenarios during induction include:

  • The animal sinks into a dog sitting position then slides into sternal recumbency. At this point, the animal can be safely approached, and the eyes covered. After the drugs have taken effect, the animal can be pulled into lateral recumbency, especially if prevented from doing so on its own due to leaning up against a wall.
  • The animal hugs the wall/corner and head presses or otherwise wedges itself into a corner preventing it from falling. Ropes, PVC, or bamboo pole can be used to repel or pull the animal from corner/wall.
  • It continues pacing or circling despite ataxia. Staff should be prepared to trip or cast the animal with ropes (using ropes). Supplemental anesthesia should also be considered.
  • The animal may become rigid, extend its head and neck in a stargazing posture, and fall over backwards. Limiting head and spinal trauma can be done by adequately preparing the stall. Distracting the animal with a pole may keep the center of gravity forward over the front limbs or a rope can be tossed over the back of the neck and withers to try to keep the animal from falling backwards.
  • Rear legs may splay especially if there is not much traction. This is corrected by repositioning the animal.
  • The animal may hit its head against wall so consideration should be given to how to best reduce or prevent this impact.
  • The animal may fall suddenly from a standing position.

Positioning

The head and neck are supported by two to three people as soon as possible during the induction period. It is best to cover the eyes and place ear plugs at this point. Noise should be kept to a minimum. Eight to 10 people are usually necessary to pull, rotate, spin, or otherwise relocate and reposition the animal in the stall. It takes at least four people per side of the animal to roll the animal over, and another three to support the head and neck. The legs are tucked up against the body and the giraffe is gently pushed over. It works best to loop 3-inch straps around the animal to assist in pulling it over. The animal should be pulled away from walls as much as possible such that there is safe access around the animal. Giraffes are usually positioned in lateral recumbency, legs extended with the down limbs pulled forward, and with the head and neck supported at a level above the rumen (usually 45–60 degrees).

Maintenance

Once the animal is properly positioned, the neck board is placed under the down shoulder to support the head and neck. The cervical vertebrae should be maintained in a straight, flat, and natural position with no kinks. Any kinks that develop should be quickly corrected. Massaging the neck muscles may be beneficial. The nose is usually pointed downwards, and the tongue pulled out of the mouth to clear the airway and facilitate drainage of saliva. Padding the down hip, shoulder, and down limbs may be necessary if the procedure will be prolonged or if the substrate is hard. Caution should be used when working around the legs, as the animal may kick without warning. Caution should also be used when supporting the head as an animal can lift or throw its head backwards and injure personnel. Ropes or straps can be preplaced on the limbs to reduce spontaneous movement.

Recovery

Problems encountered during recovery are similar to induction. Most problems are associated with the animal being unable to find its center of gravity. Giraffe usually stand with the rear limbs first. They do need enough room to rock and roll sternal so should not be positioned with the feet against a wall. Pre-placing two straps or ropes under the base of neck may be useful to prevent the animal from going over backwards until it regains its balance. Once the procedure is completed, all equipment and supplies except for the neck board should be removed from the stall. All four limbs are pushed up against the body (alternating hind and front limbs) as best as possible. The animal can be supported in this position so it cannot roll back on to its side. All unnecessary personnel should leave the stall. Exits must remain clear. Four people are usually needed to stay with giraffe and assist with neck and head control during the initial recovery process. Once the animal starts to move or react to stimuli, the neck board can be removed, but it will still be necessary to control the head above the rumen. The animal may suddenly swing its head. At this point, all personnel should move away to prevent injury. The eyes can remain covered as this will keep the animal calm. The eye covered should be tied or taped at this point as it should be able to fall off as the animal moves. Four staff members (one or two on the end of each strap or rope) can be used to facilitate manual control of the neck and head once the animal is standing. These can be removed once the giraffe has control of its head.

Post-Anesthesia

The giraffe should be monitored for 12–24 hours following anesthesia. Drug recycling can occur 6–72 hours post recovery. Clinical signs include lethargy, dullness, decreased response to external stimuli, dull eyes, inappetence, salivation, drooping tongue, ataxia, leaning against a wall, or incoordination. Administering additional antagonist 6–8 hours after the procedure is strongly recommended.

 

Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

Nadine Lamberski, DVM, DACZM
San Diego Zoo Safari Park
Escondido, CA, USA


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