DISEASE SUMMARY PAGE

Calcium-Vitamin D Metabolism Imbalance (with special reference to Hedgehogs, Elephants, Bears and Bonobos)

Summary Information
Diseases / List of Micronutrient (Vitamin / Mineral) Diseases / Disease summary
Alternative Names
  • Rickets
  • Fibrous osteodystrophy
  • Osteomalacia

See also: 

Disease Agents
  • Vitamin D (deficiency). (J18.38.w1)
  • Dietary imbalance [calcium deficiency] suspected. (J3.118.w3)
  • Malnutrition (B22.27.w3)
In Elephants:
  • The most common causes in juvenile elephants are: 
    • Vitamin D deficiency. (B10.49.w21, B35.14.w9, P505.9.w3) 
      • Note: If the elephant has adequate exposure to sunlight, additional vitamin D in the diet should not be required. (P505.9.w3)
    • Calcium deficiency. (B10.49.w21, P505.9.w3)
    • Calcium:phosphorus ratio imbalance. (B10.49.w21, B35.14.w9, P505.9.w3)
  • In a hand-reared elephant calf with a chronic problem with diarrhoea, it was thought that the diet fed was nutritionally complete, although it was commented that the bioavailability of the skeletal nutrients provided was not known. It was considered possible that there was a malabsorption, possibly associated with the ongoing diarrhoea. (P36.1994.w3)
In Bears:
  • In two hand-reared Ursus maritimus - Polar bear, deficiency in vitamin D3 intake in comparison to requirements. Polar bear cubs may have a relatively high requirement for oral vitamin D3 intake as well as for calcium and phosphorus. Functional steatorrhoea may have contributed to the problem. The high growth rate of the cubs also may have been contributory. (J2.30.w3)
  • In yearling Ursus arctos - Brown bear and Ursus maritimus - Polar bear, deficiency of calcium in a diet of mainly horse meat with some fruit and vegetables. (B16.9.w9)
In Bonobos:
  • In a male bonobo infant, hypovitaminosis D. (D391.w2, P86.5.w1)
Infectious Agent(s) --
Non-infectious Agent(s)
Physical Agent(s) --
General Description
In Hedgehogs:
  • Reported associated with a diet deficient in Vitamin D. (J18.38.w1)
  • Seen in one hedgehog of a late-born litter of three overwintered in captivity (one of the other hedgehogs had been released and the third had died). The possibility was raised that one hedgehog had "monopolised" the food such that the other individuals did not receive an adequate diet. (J3.118.w3)
  • In five hedgehogs presented at the Zoological Society of London it was noted that they had all been kept in confinement and that there was a need for more information regarding the dietary requirements of hedgehogs in captivity. (J46.1931.w1)
In Elephants:
  • Rickets has been reported in elephant calves in which there was a calcium:phosphorus ratio imbalance of the diet. (B10.49.w21, B64.27.w4, B214.3.7.w3)
  • Rickets has been reported in hand-reared elephants with insufficient vitamin D intake. (B35.14.w9)

Elephas maximus - Asian Elephant

  • A nine-month-old male Elephas maximus - Asian Elephant which had been hand-reared on an artificial diet after rejection by his dam was diagnosed with osteodystrophy and associated pathological fractures of both distal humeri. (P36.1994.w3)
  • Classic rickets lesions have been found in Elephas maximus - Asian Elephant. (B35.14.w9)
  • Rickets cases have been reported in elephant calves from East Asia. (P501.1.w2)

Loxodonta africana - African Elephant

  • Healed rickets was diagnosed in a three-year-old female elephant, with lack of exposure to sunlight over six months (winter, while maintained indoors) and unknown previous nutrition. (J4.163.w5)
  • A juvenile Loxodonta africana - African Elephant showing limb deviation was reported to improve following the supplementation of the diet with bone meal and Vitamin D3. (B450.9.w9)
In Bears:
In Bonobos:
  • A male bonobo infant died at 18 months due to hypovitaminosis D. (D391.w2, P86.5.w1)
  • Note: rickets has been seen in several great apes. (B336.39.w39)
Clinical signs:
In Hedgehogs:
  • Deformities of the spine and ribs reported. (J18.39.w1)
  • "Advanced degree of osteomalacia and rickety deformity of the spine, ribs, and long bones." in five hedgehogs (Erinaceus europaeus - West European Hedgehog) presented to the Zoological; Society of London, all following maintenance in captivity by individuals elsewhere; all the animals died within two months of presentation. (J46.1931.w1)
  • Severe anorexia and lethargy, hyperpnoea, ataxia and falling, teeth slightly loose (one individual). (J3.118.w3)
  • Weight loss and diarrhoea may have been noted. Exostoses of joints may be palpable. (B291.12.w12)
  • Calcium deficiencies have resulted in stunted growth, short, deformed limbs and a squatting gait. (B16.9.w9)
In Elephants:
  • Pica, lameness, pathological fractures, deformities of the limbs and face and reluctance to move may be seen with calcium deficiency in young elephants. (B35.14.w9)
  • Skeletal deformities. (B10.49.w21, J4.163.w4, P505.9.w3)
    • Lateral deviation of the right tibiotarsus. (J4.163.w4)
  • Lameness. (B10.49.w21, J4.163.w4, P36.1994.w3)
    • Progressive lameness and discomfort. (P36.1994.w3)
  • Muscle weakness. (P505.9.w3)
  • Pathological fractures of both distal humeri. (P36.1994.w3)
  • Signs of tetany. (B10.49.w21, B64.27.w4, B214.3.7.w3)
    • Muscular spasms, cramps, signs of acute distress, sometimes convulsions. (B453.7.w7)
  • Clinical pathology:
    • Elevated alkaline phosphatase activity: over 20 K-A units (normal range 4 - 15 units). (B35.14.w9)
  • Radiography: 
    • In a nine-month-old hand-reared calf, radiographic studies revealed pathological fractures of both distal humeri with callus formation. (P36.1994.w3)
    • Widening of the epiphyseal plates of affected bones (e.g. limb bones such as the humerus, and ribs) with rickets due to vitamin D deficiency. (B35.14.w9)
    • "Lipping" of the epiphysis, which is relatively normal in width, folding fractures and fibrous osteodystrophy may be seen in young animals with calcium deficiency. (B35.14.w9)
In Bears:
  • In yearling Ursus arctos - Brown bears and Ursus maritimus - Polar bears, stunted growth, limb deformities and a chronically altered gait, described as a "squatting gait". (B16.9.w9)
  • Partial anorexia, frequent vocalisation and apparent pain in one of two Ursus maritimus - Polar bear cubs affected. (J2.30.w3)
  • Clinical pathology
    • In two Ursus maritimus - Polar bear cubs
      • Serum calcium and phosphorus were high, not low, compared to reference values for captive and wild polar bears. (J2.30.w3)
      • ALP was raised (50 - 60 times normal), probably indicating increased osteoblastic activity as well as growth (levels may be up to six times normal values in growing cats and dogs). (J2.30.w3)
      • Serum levels of 25-OH-D measured by radioimmunoassay were low (6.3 and 7.3 ng/mL), values which are compatible and diagnostic for rickets in human infants. (J2.30.w3)
Further Information
In Elephants:
  • Rickets is seen most commonly in hand-reared elephants not given sufficient vitamin D. (B35.14.w9)

Pathology
In Hedgehogs:
  • Radiographic evidence of generalised decreased bone density plus midshaft fractures in both femurs (one individual). (J3.118.w3)
  • Bones may be easily cut, bones may be deformed and joints may show exostoses.
In Elephants:
  • Loxodonta africana - African Elephant
    • In a three-year old female calf, "widening and flattening of the tibial metaphysis at its epiphyseal junction, irregularity of the epiphyseal line, and radiodensity in the juxta-epiphyseal area." (J4.163.w4)
  • Elephas maximus - Asian Elephant
    • In a nine-month old hand-reared calf:
      • All bones could be cut easily. (P36.1994.w3)
      • On histological examination, bone sections revealed osteodystrophy, characterised by fibrous thickening of the periosteum, replacement of the cortex and marrow space with fibrous connective tissue, and thin marrow trabeculae of the woven bone; large osteoclasts were found occasionally. (P36.1994.w3)
      • A diagnosis of osteodystropy was made based on the pathological findings. (P36.1994.w3)
In Bears:
  • In two Ursus maritimus - Polar bear cubs, radiographically, there was generalised decreased bone density, decreased cortical distinction and mildly widened metaphyses in one cub. In both cubs, multiple fractures of long bones and bowing of long bones. The cubs were non-ambulatory (due to their young age) and the fractures were not displaced. (J2.30.w3)
  • Molars partially enclosed in a greatly thickened fibrous follicle were noted in two London Zoo bears (Ursus sp.); suffering from severe rickets. the skull bones were greatly thickened, but soft enough to be cut with a stout knife. the follicles of the maxillary molars were "greatly enlarged and projected as rounded fibrous tumours into the orbits and zygomatic fossae." (B471.25.w25)
Treatment:
In Hedgehogs:
  • Appropriate vitamin and mineral administration, plus correction of the diet. (B291.12.w12)
In Elephants:
  • Appropriate vitamin D3  and calcium supplementation of the diet. (B450.9.w9, P36.1994.w3, P505.9.w3)
    • A calcium:phosphorus ratio of 1:1 for maintenance at 15 mg each per 45 kg bodyweight per day, and a ratio of 1.4:1 for initial treatment has been suggested for elephants, rhinos and tapirs (based on data for horses). (B35.14.w9)
  • Vitamin D should be provided at 200 IU/kg feed daily. (B35.14.w9)
  • An orthotic brace has been used to support the affected limbs. (B10.49.w21, J4.163.w4)
    • In a three-year old female calf, under sedation the foot was manipulated into a neutral position, a plaster mould was made of the foot and used as a template for a corrective orthesis, a brace reaching from the sole to the stifle, placed on the foot over a single layer of stockinette and attached with two straps (at the rear, out of reach of the trunk). This was removed and replaced every few days, for six months, at which time the deformity was found to be corrected. (J4.163.w4)
  • Euthanasia was required when the condition of an elephant calf with rickets and associated pathological fractures deteriorated. (P36.1994.w3)
In Bears:
  • Supplementation with vitamin D3 and with calcium. (J2.30.w3)
    • Two hand-reared Ursus maritimus - Polar bear cubs with rickets were each given 0.25 mL of an injectable vitamin A/Vitamin D preparation (Injacom 100 AD3, Hoffman-LaRoche, Nutley, New Jersey, USA; each 1mL contains 100,000 IU vitamin A and 10,000 IU vitamin D3) intramuscularly, with a further 0.5 mL given six weeks later, together with a change in oil added to their milk, from safflower oil (no vitamin D3) to cod liver oil (5ml per 100 ml milk; one mL contains about 85 IU vitamin D3) and added calcium in the diet: 25 ml of Neo-Calglucon per day (0.24 g calcium per mL) during the recovery period, then gradually reduced over the following months. (J2.30.w3)
      • Note: With this treatment, 25-OH-D levels in serum rose from low values (as seen in human infants with rickets) to levels above the normal reference ranges for humans: from 6.2 and 7.3 ng/mL to 130 and 118 ng/mL (female and male cub respectively); for comparison, levels in two older polar bears (a six-year-old and a ten-month-old) were 116 ng/mL and 92 ng/mL, while that from a mother-reared zoo cub at eight weeks old was measured at 50.2 ng/mL (this may have been lower than the actual value, due to multiple centrifugations required to separate serum from clotted heart blood obtained at necropsy). (J2.30.w3)
Prevention:
In Elephants:
  • Ensure proper nutrition including sufficient, but not excessive, calcium and an appropriate calcium:phosphorus ratio; exposure to sunlight should provide adequate vitamin D. (P505.9.w3)
  • A calcium:phosphorus ration of 1:1 for maintenance at 15 mg each per 45 kg bodyweight per day has been suggested for elephants, rhinos and tapirs (based on data for horses). (B35.14.w9)
  • Diets successfully used in elephants often have calcium: phosphorus ratios of up to 2:1. (V.w81)
In Bears:
  • Ensure adequate diet with appropriate vitamin and mineral supplementation: 
    • For polar bear cubs, a suggested diet is "100% Esbilac with half-and-half milk added at a rate of 10% per week until a ratio of 60% Esbilac and 40% half-and-half is reached while the cubs are growing and if they are not bloating." (J2.30.w3)
    • If bears are fed mainly ground muscle meat, add calcium carbonate at 400 mg/100 g meat, plus a multi-vitamin and trace mineral supplement at a rate as indicated by the manufacturer of the supplement. (B16.9.w9)
In Bonobos:
  • Provision of UV light every day, by access to natural sunlight when possible, and using artificial UV light when access to the outdoors is not possible. (D391.w2, P86.5.w1)
  • Great apes should be supplemented with Vitamin D and given access to natural sunlight. (B336.39.w39)
Techniques linked to this disease
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Host taxa groups /species Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken).

(List does not contain all other species groups affected by this disease)

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