Fatal herpesvirus encephalitis in a reticulated giraffe (Giraffa camelopardalis reticulata)

Fatal meningoencephalitis caused by equine herpesvirus-1 (EHV-1) was diagnosed in a reticulated giraffe (Giraffa camelopardalis reticulate). The giraffe died following a history of stumbling, incoordination, and abdominal pain. Gross examination of the brain revealed asymmetric edema and red-brown discoloration, predominantly within the telencephalon. Microscopically, there was perivascular lymphohistiocytic cuffing, multifocal gliosis, and neuronal necrosis in the cerebrum. Necrotic neurons contained acidophilic intranuclear inclusions. EHV-1 was isolated from the brain of the giraffe, and polymerase chain reaction was positive on sections of the brain. Immunohistochemistry using an EHV-1-specific antibody identified positive staining in neurons, astrocytes, and endothelial cells. The giraffe had been housed with a group of zebras that were serologically positive for EHV-1 and suspected as the source of infection. This raises concerns for cross-species transmission of EHV-1 when housing equids together with other species in zoologic collections.     

Arthroscopic surgery in a reticulated giraffe (Giraffa camelopardalis reticulata).

An 8-mo-old captive male reticulated giraffe (Giraffa camelopardalis reticulata) developed an acute lameness (grade IV/V) of the right forelimb, with swelling of the metacarpophalangeal joint. A traumatic injury was suspected based on clinical, radiographic, and arthroscopic evaluation. Several abnormalities were identified arthroscopically, including synovitis, cartilage damage, and an osteochondral fragment. Medial collateral ligament damage was also suspected based on radiographic evaluation. Arthroscopy provided a means of diagnosis and treatment of the abnormalities identified. The lameness in this giraffe resolved within 6 wk following arthroscopic surgery.     

Teratoma of the umbilical cord in a giraffe (Giraffa camelopardalis reticulata)

A 12-year-old pregnant female giraffe (Giraffa camelopardalis reticulata) died approximately 2 months prior to her anticipated parturition date. At necropsy, a mass measuring approximately 20 x 36 x 20 cm was observed, attached to the umbilical cord, the latter being otherwise normal in appearance. Histologically, the mass contained 3 germinal tissue components with areas of squamous epithelium, respiratory epithelium, primitive neural tissues, glial tissue, peripheral nerve, adipose tissue, cartilage, and smooth muscle. Based on these findings, the tumor was diagnosed as a teratoma originating from the umbilical cord. This is possibly the second reported case of umbilical cord teratoma in animals.     

Distribution and status of the desert-dwelling giraffe (Giraffa camelopardalis angolensis) in northwestern Namibia

The population density and distribution of desert dwelling giraffes was estimated in three study areas in the Hoanib River catchment, northwestern Namibia. Giraffe population densities (0.01 giraffe/km²) were equal to the lowest recorded in Africa with population numbers fluctuating over past decades. Sex ratios, herd sizes and age categories differed between all the study areas, while a weak correlation (r² = 0.66, P < 0.001) in giraffe aggregation and the hot dry season was observed in the Ombonde River. Seasonal move ment and use of the riparian environments varied, with large fluctuations observed in the east of the catchment, while the hot dry season influx and use in the riparian woodland coincided with Faidherbia albida podding.     

Energy and fibre intake in a group of captive giraffe (Giraffa camelopardalis) offered increasing amounts of browse

We investigated the effect of diet on intake of energy and fibre in a group of three captive adult giraffe by weighing offered diet items and leftovers for 7 days after an adaptation period of 7 days. Digestion coefficients were calculated using, as internal marker, the acid detergent lignin content of a faecal sample pooled from subsamples taken during the last 5 days of intake measurement. Two lucerne hay-only diets of differing quality (L1, L2) were fed, as well as the regular diet of lucerne hay and concentrates (L2C), and the regular diet supplemented with 3 or 6 kg of edible, fresh browse material (L2CB3, L2CB6). The proportion of roughage in the ingested diets L2CB6 (45 +/- 5% dry matter), L2CB3 (35 +/- 3%) and L2C (37 +/- 10%) did not differ significantly. Digestible energy intake was low on the hay-only diets [L1: 0.28 +/- 0.06 MJ/kg body weight (BW)0.75; L2: 0.33 +/- 0.10 MJ/kg BW0.75] and increased from L2C (0.60 +/- 0.13 MJ/kg BW0.75) to a significant increase with L2CB3 (0.72 +/- 0.17 MJ/kg BW0.75); no further increase was obvious for L2CB6 (0.63 +/- 0.15MJ/kg BW0.75). The results confirm that giraffes are unlikely to meet energy requirements on lucerne hay-only diets. In a feeding scenario where both lucerne hay and the concentrate component of the diet are fed ad libitum, the animals tended to exchange hay for browse when browse was added. Only the higher level of browse supplementation led to a potentially beneficial increase in fibre intake. Whether additional browse supplementation will lead to increased intakes in a feeding scenario with restricted concentrate provision can be suspected but remains to be demonstrated.     

Surgical resolution of an avulsion fracture of the peroneus tertius origin in a giraffe (Giraffa camelopardalis reticulata)

A 4-mo-old, 185-kg male giraffe (Giraffa camelopardalis reticulata) was presented due to stifle effusion and lameness of 3-wk duration. Radiographs revealed a fracture of the extensor fossa of the lateral trochlear ridge of the femur at the origin of the peroneus tertius. Under anesthesia, dysfunction of the reciprocal apparatus was documented by flexing the stifle while the tarsus remained extended. An avulsion fracture of the origin of the peroneus tertius and extensor digitorum longus muscle was diagnosed. An exploratory arthroscopy of the femorotibial joint was followed by arthrotomy to excise the large bone fragment from its soft tissue attachments. Because of the fractious temperament of the animal, postoperative care was restricted to stall rest for 3 mo, and no postoperative complications arose. Only a mild residual lameness remained by 6 mo after surgery.     

Evaluation of progesterone levels in feces of captive reticulated giraffe (Giraffa camelopardalis reticulata).

Fresh fecal samples were collected from seven adult female reticulated giraffe (Giraffa camelopardalis reticulata). Samples were collected for several weeks before, during, and for a few weeks after gestation. Fecal samples were analyzed for progesterone levels by radioimmunoassay. There were significant differences in progesterone levels between pregestational and gestational samples and between gestational and postgestational samples. These results demonstrate that fecal progesterone levels are useful in determining pregnant versus nonpregnant reticulated giraffe.     

Comparison of in vitro tests for evaluation of passive transfer of immunoglobulins in giraffe (Giraffa camelopardalis).

Serum samples from captive giraffe (Giraffa camelopardalis) were tested to assess passive transfer of immunoglobulins using in vitro methods developed for domestic ruminants. Estimated immunoglobulin levels were compared using five tests (protein electrophoresis, total protein refractometry, zinc sulfate turbidity, glutaraldehyde coagulation, and sodium sulfite turbidity). A linear relationship was observed among total protein, gamma globulin (electrophoretic measurement), and immunoglobulin level based on spectrophotometric measurement of zinc sulfate turbidity. Nonquantitative assays also demonstrated statistical correlation with the quantitative methods. Using criteria similar to those established for domestic species, cutoff values for failure of passive transfer (FPT) were established for these tests in neonatal giraffe: 1) total protein <6.0 g/dl; 2) gamma globulin < 0.5 g/dl; 3) estimated immunoglobulin level < 1,000 mg/dl (zinc sulfate turbidity); 4) glutaraldehyde coagulation test negative; or 5) no visually detectable turbidity in 16% sodium sulfite or Bova-S negative. Retrospective examination of the medical histories showed a strong statistical association between animals designated as having FPT and those that were removed from their dams based on clinical assessment to be hand-reared. Application of these tests in the field should allow earlier detection and intervention for FPT in neonatal giraffe.     

Mortality of captive giraffe (Giraffa camelopardalis) associated with serous fat atrophy: a review of five cases at Auckland Zoo.

Five giraffe (Giraffa camelopardalis) died peracutely within an 8-yr period. The giraffe were maintained in an outside enclosure during the day and moved under shelter at night. All the deaths occurred in winter. All the dead giraffe had serous fat atrophy at postmortem. The giraffe were fed good quantities of browse, together with alfalfa hay and commercial supplements. Retrospective analysis of the dietary ingredients showed that the diets were energy deficient. Subsequent additional high-energy feeds have caused a marked increase in surviving giraffe body weights although energy levels consumed were at the lower end of current recommendations. The relationship between low-energy reserves, high-energy demand in colder temperatures, and the possibility that hypoglycemia is a credible cause of the collapse of giraffe in these circumstances, is postulated to be the likely pathogenesis of giraffe deaths, previously reported elsewhere under the generic term "peracute mortality syndrome".     

Orbit orientation and eye morphometrics in giraffes (Giraffa camelopardalis)

Giraffe are thought to have excellent vision. We measured eye size, orbit orientation and retina surface area in 27 giraffes of both sexes ranging in age from neonates to mature adults (>10 yrs), to assess how it changes with growth, whether their eye anatomy correlates with their apparently excellent vision and lifestyle, and we have compared our findings with those for other large mammals to assess whether giraffe eye anatomy is unique. We found that giraffe eye volume increases from 33 cm³ at birth to approximately 65 cm³ in adults. The focal (axial) length increases from c. 40 to 48 mm in adults and retina surface area from c. 3000 mm² at birth to 4320 mm² in adults. The orbital axis angle at birth is c. 73° and the horizontal visual field mainly monocular and panoramic. With age the axis angle becomes more acute to c. 50° in adults and the visual field more binocular, changes that occur concurrently with increasing neck length. These results show that the giraffe eye and retinal surface area are larger than in all other ungulates, and their visual fields more binocular, attributes which are consistent with the idea that they have excellent vision.     

Gross Anatomy of the Intestine in the Giraffe (Giraffa camelopardalis)

We describe the macroscopic anatomy of the intestine of the giraffe (Giraffa camelopardalis). The small intestine was divided into duodenum, jejunum and ileum as usual. The caecum was attached to the ileum by a long ileocaecal fold, and to the proximal ansa of the ascending colon by a caecocolic fold. The ascending colon was the most developed portion of the gross intestine and had the most complex arrangement with three ansae: the proximal ansa, the spiral ansa and the distal ansa. The proximal ansa completely encircled the caecum, describing a 360° gyrus, and represented the widest portion of the intestine. The spiral ansa was formed by three and a half centripetal gyri, a central flexure and three centrifugal gyri. The last centrifugal gyrus left the spiral and described nine flexures of different form and direction over the left side of the mesentery. The two portions that formed each of these flexures ran parallel to each other. The last part of this gyrus ran parallel to the jejunum. When compared with domestic cattle, giraffe had a comparatively short small intestine and a comparatively long large intestine, with a resulting small ratio of small:large intestine. Reasons are presented why this should be considered a peculiarity of cattle‐like ruminants rather than a different representative of a browser–grazer dichotomy in general.     

Serum chemistry comparisons between captive and free-ranging giraffes (Giraffa camelopardalis)

Serum chemistry analyses were compared between captive and free-ranging giraffes (Giraffa camelopardalis) in an attempt to better understand some of the medical issues seen with captive giraffes. Illnesses, including peracute mortality, energy malnutrition, pancreatic disease, urolithiasis, hoof disease, and severe intestinal parasitism, may be related to zoo nutrition and management issues. Serum samples were collected from 20 captive giraffes at 10 United States institutions. Thirteen of the captive animal samples were collected from animals trained for blood collection; seven were banked samples obtained from a previous serum collection. These samples were compared with serum samples collected from 24 free-ranging giraffes in South Africa. Differences between captive and free-ranging giraffes, males and females, and adults and subadults were analyzed by using a 2 x 2 x 2 factorial and Fisher's least significant difference for mean separation; when necessary variables were ranked and analyzed via analysis of variance. Potassium and bilirubin concentrations and alanine aminotransferase (ALT) activities were different between captive and free-ranging giraffes, but all fell within normal bovid reference ranges. The average glucose concentration was significantly elevated in free-ranging giraffes (161 mg/dl) compared with captive giraffes (113 mg/dl). All giraffes in this study had glucose concentrations higher than bovine (42-75 mg/ dl) and caprine (48-76 mg/dl) reference ranges. Differences were also seen in lipase, chloride, and magnesium though these findings are likely not clinically significant. There were no differences detected between sexes. Adults had higher concentrations of potassium, total protein, globulins, and chloride and higher gamma glutamyltransferase activities, whereas subadults had higher concentrations of phosphorus. Within the captive group, nonimmobilized animals had higher concentrations of total protein and globulins. Captive giraffe diets need further investigation to determine if the differences seen in this study, especially glucose and bilirubin concentrations and ALT activities, may result in some health problems often seen in captive giraffes.     

The Structure of the Masseter Muscle in the Giraffe (Giraffa camelopardalis)

In the giraffe (Giraffa camelopardalis), the masseter muscle was divided into several layers. The superficial and more medial (second) tendinous sheets of the masseter muscle fused with each other at the dorso-caudal part and a fleshy portion was located between these tendinous sheets. In the rostral part, the most superficial tendinous sheet turned around as a compact tendon and attached to the facial crest (Crista facialis). The turned tendinous sheet, however, never fused with the second tendinous sheet and this layer of the masseter muscle, that originated from the facial crest with the turned sheet, was inserted into the mandible with its fleshy portion. In the cattle, goat, sheep and Sika deer, the rostral layer of the masseter muscle arises from the facial crest with its fleshy portion and is inserted into the tubercle on the mandible through the strong tendinous sheet. In this study, the takin also showed the same structure of the masseter muscle. In the giraffe, however, the rostral layer inserted into the mandible through the strong tendinous sheet could not be distinguished, thus, there was no conspicuous tubercle on the mandible. Moreover in the masseteric region of the skull.,the giraffe was similar to the Sika deer in several ways. However, it is suggested that the giraffe exerts smaller forces on the cheek teeth than does the Sika deer because of its longer Margo interalveolaris.     

Diagnosis and treatment of a fractured third phalanx in a Masai giraffe (Giraffe camelopardalis tippelskirchi).

A 10-yr-old male Masai giraffe (Giraffe camelopardalis tippelskirchi) presented with acute right forelimb lameness. Radiographs revealed a fracture of the medial claw of the distal phalanx penetrating into the distal interphalangeal joint. The giraffe was sedated while it was standing in a chute, and a wooden "hoof block" was applied to the lateral claw of the same limb. The animal was no longer lame 3 days after the procedure. Subsequent treatments included vitamin E, phenylbutazone, and glycosaminoglycans. For 7 wk it was maintained in a small holding yard on packed sand during the day and on deep sand during the night. The hoof block slowly wore down, and at 7 wk, it was placed back on concrete in the evening. At 8 wk, the block had completely worn off and the animal was no longer lame, but radiographs indicated minimal fracture healing. Radiographs performed at 7 mo indicated that there was still a radiolucent zone at the fracture line but calcification was evident at the margins of the fracture.     

Prevalence and histopathological characterization of Masai Giraffe (Giraffa camelopardalis tippelskirchi) skin disease in Tarangire-Manyara ecosystem,Northern Tanzania

BackgroundMasai Giraffes have declined dramatically in recent decades due to loss of habitat and illegal hunting. Hence, it is critically important that the epidemiology and etiology of so-called giraffe skin disease (GSD) is understood well.AimTo assess the prevalence and histopathological characteristics of GSD in the Tarangire-Manyara Ecosystem (TME), northern Tanzania.MethodsThe study used road transects to gather field information on GSD. Eighty-four giraffes were sighted by systematic random sampling in the six study sites. Examination of giraffes involved body distribution of lesions, severity of the lesions and whether they were associated with age and sex of the affected giraffes. Five giraffes with GSD were immobilized for tissue collection and histopathological analysis.ResultsPrevalence among adults was 79%. Affected animals typically had 1–5 lesions which were mostly moderate and were predominantly observed on the forelegs. GSD positivity rate was higher among females versus males, whereas males had a higher rate of severe lesions and generally had more lesions than females. Calves showed no lesions. All tissue sections from five affected giraffes showed the presence of large quantities of fungal elements (hyphae and spores) that involved hair shafts and sub-cutaneous tissue after staining with Grocott Methenamine Silver as special fungal staining technique.ConclusionsOur findings suggest the involvement of fungal infection in GSD pathogenesis.Clinical relevanceWe recommend further characterization of the lesions using modern molecular techniques and culture to identify primary and secondary or opportunistic etiologies, and the order in which the pathogens occur in the lesions.     

Influence of ration composition on nutritive and digestive variables in captive giraffes (Giraffa camelopardalis) indicating the appropriateness of feeding practice

The nutrition of captive giraffe (Giraffa camelopardalis ), a browsing ruminant, is challenging because browse availability is limited in zoos and rations need to be composed of compensatory feeds. In this study, ration composition for giraffes in 12 German zoos was documented and linked to animal variables that indicate suitability of nutrition. Rations differed in proportion of ration items and chemical composition resulting in various grades of accordance with feeding recommendations. An estimated daily metabolisable energy (ME ) intake (MEI ; mean ± SD ) of 0.61 MJ ME/kg^0.75 body weight (BW ; ±0.1) was sufficient to cover estimated energy requirements. Daily dry matter (DM ) intake (DMI ) was 61 g DM/kg^0.75 BW (±10) and correlated negatively to dietary ME content (p  = .009; r  = ?.596). Apparently, feed intake was regulated by energetic satiety and not by physical properties of forage. A negative correlation between produce proportion and DMI (p  = .002; r  = ?.676) led to the assumption of a low ruminal pH in giraffes fed high proportions of produce. Increasing dietary forage proportions led to an increasing duration of feed intake (p  = .045; r  = .477) and decreasing occurrence of oral stereotypies (p  = .047; r  = ?.474). The weighted average faecal particle size was larger than reported for free‐ranging giraffes, but no relation to ration characteristics among the facilities existed. The abrasiveness of rations was not excessive, as contents of silicate in faeces were similar to values from the wild. Body condition was generally acceptable, but there was no evident relation to ration characteristics. The capacity to self‐regulate DM and ME intakes with lucerne hay may work at higher forage proportions than often assumed for captive giraffes. Rations with less energetic density can result in a greater DMI , including maximisation of forage intake and reduction of oral stereotypies.     

Tooth wear in captive giraffes (Giraffa camelopardalis): mesowear analysis classifies free-ranging specimens as browsers but captive ones as grazers.

Captive giraffe (Giraffa camelopardalis) mostly do not attain the longevity possible for this species and frequently have problems associated with low energy intake and fat storage mobilization. Abnormal tooth wear has been among the causes suggested as an underlying problem. This study utilizes a tooth wear scoring method ("mesowear") primarily used in paleobiology. This scoring method was applied to museum specimens of free-ranging (n=20) and captive (n=41) giraffes. The scoring system allows for the differentiation between attrition--(typical for browsers, as browse contains little abrasive silica) and abrasion--(typical for grazers, as grass contains abrasive silica) dominated tooth wear. The dental wear pattern of the free-ranging population is dominated by attrition, resembles that previously published for free-ranging giraffe, and clusters within browsing herbivores in comparative analysis. In contrast, the wear pattern of the captive population is dominated by abrasion and clusters among grazing herbivores in comparative analyses. A potential explanation for this difference in tooth wear is likely related to the content of abrasive elements in zoo diets. Silica content (measured as acid insoluble ash) is low in browse and alfalfa. However, grass hay and the majority of pelleted compound feeds contain higher amounts of silica. It can be speculated that the abnormal wear pattern in captivity compromises tooth function in captive giraffe, with deleterious long-term consequences.