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Two species exist within the artiodactylid family of Giraffidae; the giraffe Giraffa camelopardalis and the okapi Okapia johnstoni. Giraffids first arose eight million years ago during the Miocene period, and fossil evidence suggests that the family was once much more extensive, with over 10 fossil genera described. Up to nine races or subspecies of giraffe have been described, although genetic research and the fact that distinct morphologic distinctions between groupings exist despite the lack of physical boundaries have led some authorities to consider several distinct species.
The subspecies most commonly held by zoos are the reticulated giraffe Giraffa camelopardalis reticulatathe Rothschild giraffe G. Once widespread across the African continent, giraffes are now largely confined to national parks and game farms in eastern E Giraffe Neck Jones southern Africa, with scattered populations in west Africa.
Because of its height, the giraffe has access to browse unavailable to other species and thus may coexist with grazers and smaller browsers and even livestock. Adult giraffes are rarely preyed upon by predators, but calf mortality is high. Giraffes are sociable animals usually found in dynamic, ever-changing groups, the most stable of which are those composed by mothers and their young.
Subadult males are social, whereas mature males become more solitary. At least giraffes are maintained in captivity, making the captive population self-sustaining. Discovered by science only as recently asthe okapi was the last large African mammal species to be described. The okapi is now endemic to the Democratic Republic of the Congo in central Africa, where they inhabit dense damp forests on both sides of the Congo River.
Okapis are diurnal and live alone, in pairs, or in small family groups, but relatively little is known about their social structure, largely because of their remote habitat and timid nature. Estimated remaining wild population is between 10, and 35, and the fate of these animals is closely linked to the unstable political climate of the region.
With less than animals in captivity, the okapi population is considered fragile.
With a height of up to more than 5 meters mgiraffes are characterized by their extremely long necks and long legs, with considerably longer forelimbs than hindlimbs. The head is fairly small, with two horns or ossicones and a central osseous protuberance, which is particularly developed in the males. The internal anatomy of giraffes is analogous to that of the domestic cow and other artiodactylids. Often, the gallbladder is absent, although it occurs in some individuals. Two jugular veins run immediately under the skin on either side of the ventral neck.
The skin varies in thickness from being thin on the ears and medial aspects of the legs to being thick along the neck and lateral body. The thick skin aids in edema prevention in the lower leg and forms a dermal armor for protection against predators or fighting with conspecifics. The dark patches of the skin have been suggested to have a thermoregulatory role in acting as regions where heat loss to the environment is enabled by selective vasodilation.
ly described as extraordinarily large, the giraffe heart has a relative weight of approximately. The giraffe vein has a venous valve layout similar to that in other large mammals, and no arterial valves exist. Females are larger than males. The eyes and ears are large, and the tongue long enough to reach the ear base. Males have a pair of short-haired ossicones that are directed backward. The body is short E Giraffe Neck Jones compact with a sloping back, as in the giraffe, but the neck is much shorter.
Available information on okapi anatomy and physiology is limited, but the dental formula and internal anatomy resemble those of the giraffe.
To compensate for the hydrostatic challenge of perfusing the brain, the giraffe heart generates a blood pressure twice that of other mammals, and its cardiovascular anatomy and physiology have been subject to considerable speculation and myths. Both stroke volume E Giraffe Neck Jones cardiac output are lower than in similar-sized mammals.
Blood volume is unusually low, and compliance of the vascular system is also low. The peculiar vascular anatomy—with narrow, rigid veins with low compliance in the legs and large, compliant veins in the neck region—gives rise to an interesting and nonintuitive physiologic phenomenon. The lowering of the blood pressure coincides with pooling of blood in the compliant jugular veins, giving rise to a decreased cardiac preload and consequently lower systemic blood pressure Frank-Starling mechanism. Edema in this region is prevented through a gravity-suit-like fascia and skin, prominent lymphatics, and well-developed valves in veins and lymphatics, as well as an abrupt narrowing of the arterial lumen at the level of the elbow or stifle.
Similar to camels, the giraffe is capable of varying the body temperature within a couple of degrees Celsius, saving energy otherwise needed for increasing the temperature at night and cooling during daytime. Giraffes may learn to lower their he to walk through doors only slightly higher than their withers; however, stressed or sedated animals will often not do this, which necessitates high doors for a giraffe house.
Soft flooring and lack of exercise may lead to overgrowth of feet and the need for trimming, so the giraffe should be encouraged to walk on abrasive surfaces. Coarse gravel may be used on top of concrete to provide traction and wear. Neonates require sure footing and do best when born on pasture or a thick layer of bedding to prevent splaying. Giraffes have a high surface-to-volume ratio and are adapted to tropical climates.
In moderate climates, they may be maintained in outdoor enclosures year-round. Both okapis and giraffes are prone to sterotypies, particularly those involving the tongue, and it E Giraffe Neck Jones important to incorporate in enclosure de pulleys and other systems to provide browse and enrichment items at head level.
When deing facilities for giraffids, the logistics of loading and unloading animals should also be considered. Ideally, narrow walkways leading to an appropriate docking ramp for transport vehicles should be incorporated into the de. Both giraffes and okapis are selective browsers seeking out the high-nutrient components of plants such as fresh leaves and buds. In the wild, giraffes mainly feed on Acacia species, and the natural diet of the okapi includes a variety of species.
The new diet regimens have recently been shown to lead to increased serum levels of magnesium as well as n3 and n6 fatty acids and decreased levels of phosphorus and saturated fatty acids 3641 so that blood nutrient profiles more closely match those of free-ranging giraffe. The importance of browse, for both the nutritional value and the behavioral well-being of animals, cannot be overstated and browse should be provided to the greatest extent possible, but good-quality hay and alfalfa as well as silage may be substituted.
Surplus buds and twigs from rose growers have been used successfully in okapis. Giraffes may be quite tame and may become habituated to some manipulation, including blood sample collection and light hoof trimming; however, many individuals do not respond well to this approach. The safest nonchemical method for collecting routine samples and closely examining animals is to accustom them to a chute during daily routines.
Forced physical restraint without specialized stalls or chutes is likely to be unsuccessful and dangerous. Giraffes may deliver a formidable kick with all four legs in essentially any direction. In tall narrow chutes, with secure footing for personnel as well as animals, giraffes may be physically restrained for minor procedures such as injections, blood collections, tuberculosis testing and so on, but the risks involved for the animal as well as the staff should be kept in mind.
Okapis respond well to training and positive reinforcement and poorly to physical restraint. Once they get started, giraffes have the tendency to keep walking along hallways and so on, which may be exploited for crating or loading into vehicles. A curtain with a weight at the bottom, which will fall from a horizontal position to a vertical position behind the animal when released, may be helpful to encourage the animal to take that last step into an unknown crate. Giraffe anesthesia remains a challenge because of considerations of size as well as the peculiar anatomy and physiology of these animals; however, several good protocols and excellent information resources are now available.
Standing sedation may work well, but ataxia may develop, so it is important to be prepared for the animal to go down unexpectedly.
A chute or restraint device is ideal, but a large door that can close off a triangular space may provide a similar confined area. Several drug combinations have been used with success for procedures such as clinical examinations, hoof trimming, reproductive manipulation, minor surgery, and catheter placement Table Two main schools in giraffe anesthesia exist: 1 opioid-based protocols 7116667 and 2 ketamine, combined with high-dose medetetomidine. The opioids, however, may induce excitation and hyperthermia if underdosed and result in hypoventilation when used in high dosages. The giraffe has traditionally been considered one of the most challenging animals to anesthetize, and most problems arise during E Giraffe Neck Jones and recovery.
The key to success is careful planning and the availability of trained personnel and necessary equipment. The ideal induction occurs in a well-deed restraint device, which may be opened fully once the animal is recumbent. The second-best solution is a chute-system, where a halter may be placed on the sedated giraffe prior to induction, which will allow control of the head via a rope and pulley.
The animal is then tripped with another rope while still awake enough to maintain some control of the head during the fall. If neither of these options are available, the animal may be allowed to become recumbent in a padded stall or at least in an area without major obstacles. In either case, it is crucial to gain control of the animal's head as soon as it becomes recumbent, as most injuries occur when the heavily sedated giraffe attempts to stand and falls again. For anesthetic induction in okapi, a padded restraint device is the safest option, but a quiet stall with sure footing will suffice.
With opioid-based protocols, induction may sometimes result in excitement or tumbling. A staged approach, in which sedatives are allowed to set in for 15 to 20 minutes prior to opioid administration, is preferable, and once the opioid takes effect, two experienced helpers may use mild physical restraint with mattresses or boards to prevent injury. Regurgitation under anesthesia may be a concern in both giraffes and okapis, but particularly in the latter.
The frequent early reports of regurgitation in okapis sedated with Immobilon etorphine and acepromazine was attributed to etorphine but likely largely was a reaction to acepromazine, which this author considers contraindicated in okapis. In animals fed mainly hay and pelleted feed, withholding food and water for 12 hours prior to a planned procedure is sufficient, but in animals eating large amounts of fresh browse, a hour period is advisable.
To minimize pulmonary compromise and ventilation—perfusion mismatch, a sternal position is preferable, when feasible, but giraffes generally do well in lateral recumbency for shorter periods. The neck should be kept as straight as possible, and placement of a padded board or ladder under the shoulder and onto bales of straw or similar material works well for this purpose. Performing endotracheal intubation is straightforward in giraffes. Direct visualization of the larynx is possible with the use of a long laryngoscope blade, and insertion of a relatively thin catheter to subsequently guide the endotracheal tube is a good option.
Hypoventilation is often a concern, and oxygen should be provided, whenever possible. A Hudson demand valve or similar device will provide the animal with oxygen and allow intermittent ventilation, as needed. In animals not intubated, supplemental oxygen via a deep nasal cannula and flowing at one liter per kilograms per minute is recommended.
For recovery, a quiet area with good footing should be provided. Adequate space should be available for the animal to swing E Giraffe Neck Jones head forward as it gets onto its hindfeet, and obstacles should be removed to avoid injury if the animal falls over. Reversal agents may be given intramuscularly or intravenously IM or IVdepending on the situation. The goal is to get the animal into sternal recumbency, with strong spontaneous ventilation as fast as possible, and to then keep it there as long as possible, ideally for 10 to 15 minutes.
Keeping the animal blindfolded during this time helps prevent its attempts to stand prematurely. Doxapram 0. The immobilization of free-ranging giraffes for capture purposes has little in common with controlled anesthesia for longer procedures in captive animals. The approach currently employed by most successful capture crews relies on massive dosing with potent opioids etorphine, carfentanil, thiafentanil, or a combination to reduce the time from darting to recumbency and subsequent skilled handling of the awake, but physically restrained, animal. Soon after the giraffe becomes recumbent, it is blindfolded, ears plugged, and haltered and reversal agents are administered.
Once the animal stands again after a few minutes, it is led with ropes into an open trailer used to be transported to a larger contained trailer that accommodates several animals.
Refer to Table for doses. Other methods incorporating ketamine, with or without medetomidine, to reduce the opioid dosage result in longer induction times but more controlled immobilization. Once immobilized, many minor procedures—such as diagnostic sampling, foot care, and assisted calving—may be performed. Supplementation is rarely necessary for the first 45 minutes, but after that, periodic intravenous ketamine 0. However, for longer procedures, a continuous infusion of one or more of these drugs or in combination with guaifenesin is preferable, and additional monitoring is recommended.
Inhalation anesthesia with isoflurane is another option, but reduced blood pressure and ataxia following recovery are potential concerns. At a minimum, monitoring should include heart rate and rhythm, rate and depth of ventilations, and oxygen saturation by pulse oximetry. Indirect blood pressure may be measured E Giraffe Neck Jones an appropriately sized blood pressure cuff placed around the tail base.
Measurements may not be accurate but will provide a trend to help guide supplementary drug administration, fluid therapy, and head positioning. Therefore, lifting the head will typically result in an increase in blood pressure. Invasive blood pressure monitoring or arterial samples for blood gas determination are most easily obtained from the dorsal auricular artery. End-tidal carbon dioxide, functional oxygen saturation pulse oximetryand electrocardiography are also useful in monitoring prolonged anesthesia in giraffes.
In both species, mild sedation for transport or introductions may be achieved with zuclopenthizole acetate 0. Because of size considerations and the challenges of obtaining minimal ataxia during recovery, only a rather limited array of surgical interventions have been reported in giraffes.
Tongue tip amputation, partial mandibular resection, mandibular ostrosynthesis, arthroscopy, arthrotomy, tenotomy, and castration have all been successfully performed. A laparoscopic approach has been suggested, 53 but its application would likely be limited. Several cases of colonic obstruction have been documented, and aggressive supportive care and early surgical intervention have been advocated.E Giraffe Neck Jones
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