Occurrence and pattern of long bone fractures in growing dogs with normal and osteopenic bones

A retrospective study was undertaken to record the occurrence and pattern of long bone fractures, and the efficacy of Intramedullary (IM) Steinmann pin fixing in growing dogs. All the records of growing dogs during a 10-year-period were screened to record the cause of trauma, the age and sex of the animal, the bone involved, the type and location of the fracture, the status of fixation, alignment, maintenance of fixation and fracture healing. The results were analysed and comparisons were made between growing dogs with normal and osteopenic bones. Among the 310 cases of fractures recorded, the bones were osteopenic in 91 cases (29%). Minor trauma was the principal cause of fracture in dogs with osteopenia (25%), and indigenous breeds were most commonly affected (38%). Fractures in dogs with osteopenic bones were most commonly recorded in the age group of 2-4 months (53%), whereas fractures in normal dogs were almost equally distributed between 2 and 8 months of age. Male dogs were affected significantly more often in both groups. In osteopenic bones, most fractures were recorded in the femur (56%), and they were distributed equally along the length of the bone. Whereas in normal bones, fractures were almost equally distributed in radius/ulna, femur and tibia, and were more often recorded at the middle and distal third of long bones. Oblique fractures were most common in both groups; however, comminuted fractures were more frequent in normal bones, whereas incomplete fractures were more common in osteopenic bones. Ninety-nine fracture cases treated with IM pinning (66 normal, 33 osteopenic) were evaluated for the status of fracture reduction and healing. In a majority of the cases (61%) with osteopenic bones, the diameter of the pin was relatively smaller than the diameter of the medullary cavity (<70-75%), whereas in 68% of the cases in normal bones the pin diameter was optimum. The status of fracture fixing was satisfactory to good in significantly more osteonormal (59%) than osteopenic dogs (42%). Fracture healing, however, was satisfactory in significantly more cases with osteopenic than normal bones. The appearance of callus was relatively early and the amount of bridging callus was relatively large in greater number of osteopenic bone fractures. Mal-union and non-union were recorded more often in osteopenic cases than in normal cases. However, the incidence of bone shortening and osteomyelitis was significantly higher in normal bones than in osteopenic bones.     

Asceptic necrosis of bone in a dog

Necrosis of intramedullary bone and bone marrow elements is reported in the long bones of a dog. Radiographically lesions were evident as an irregular increase in intramedullary density. On gross postmortem examination necrotic tissue appeared as yellow-white deposits on the endosteal surface and in the medullary cavity. Microscopically, necrotic bone had empty lacunae and was often covered by basophilic, woven bone. The cause and pathogenesisof aseptic necrosis of bone are discussed.     

Postnatal limb bone growth in relation to live weight in pigs from birth to 84 days of age.

Long limb bones were dissected from 30 Camborough x Canabrid pigs serially slaughtered at birth, 14, 28, 56, and 84 d of age to determine the growth patterns of long limb bones (humerus and radius for the forelimb and femur and tibia for the hindlimb) in relation to live weight from birth to 84 d of age, weighing up to approximately 31 kg. Relationships between individual long limb bone measurements (Y) and live weight or transformations of live weight (X) were evaluated using allometric analyses. Hindlimb bones tended to have higher growth coefficients than forelimb bones (P < .05), suggesting an anterior-posterior gradient of long limb bone growth. However, centripetal gradients of growth for long limb bones were not evidential (P > .05). Greater diameter growth compared with length growth of the long limb bones indicated that the differentiation in growth for diameter and length of the long limb bones was an effective response to the functional requirements of standing, walking, and running following birth.     

Osteopetrosis in a neonatal donkey

Osteopetrosis is a rare disorder characterised by a defect in osteoclastic bone resorption. This report describes osteopetrosis in a neonatal donkey that suffered a displaced tibial fracture. Radiographic examination identified generalised reduction in medullary cavity size, thickened mid‐diaphyseal cortices and conical metaphyseal bone extending toward the mid‐diaphysis of long bones. Postmortem examination identified additional fractures and brittle bones. Histologically, osteoclasts were absent in multiple bone sections. Diaphyseal cortices consisted of concentric bone lamellae with marrow tissue infiltration. Large wedges of secondary spongiosa extended from the metaphyseal growth plate. Clinical and histopathological features were similar to an osteoclast‐deficient, autosomal recessive form of osteopetrosis in humans.     

IMAGING DIAGNOSIS—MEDULLARY TIBIAL INFARCTION IN A HORSE

An Andalusian Stallion with left hind limb lameness had a radiolucent lesion in the medullary cavity of distal tibial metaphysis. After euthanasia for other disease, the tibia was examined with magnetic resonance (MR). The MR imaging sequences were characterized by a double line sign, although showing quite different lesion area intensities. Histologically, the lesion was compatible with medullary infarction being characterized by normal spongy bone, areas of abundant fibrous tissue and numerous necrotic adipocytes in various stages of destruction.     

Zollinger-Ellison syndrome and myelofibrosis in a dog

Zollinger-Ellison syndrome and myelofibrosis were diagnosed concurrently in a 10-year-old neutered female Brittany Spaniel. Documentation of gastric ulceration, hypergastrinemia, and gastrin-secreting islet cell tumor with splenic metastases facilitated the diagnosis of Zollinger-Ellison syndrome. Patchy long-bone medullary sclerosis, nonregenerative anemia and thrombocytopenia, multiple acellular bone marrow aspirates, marked splenic extramedullary hematopoiesis, and acellular core bone marrow biopsy with areas of necrosis and fibrosis supported the diagnosis of myelofibrosis. Despite the medical and surgical management attempted, the dog was euthanatized because of signs of severe intractable bone pain. Myelofibrosis has been documented in association with canine and human neoplastic disease. A direct causal relationship between gastrinoma and myelofibrosis was not clearly established in this instance.     

RADIOGRAPHIC AND PATHOLOGIC FEATURES OF OSTEOPETROSIS IN TWO PERUVIAN PASO FOALS

The radiographic and pathologic findings of two Peruvian Paso foals with osteopetrosis are described. Both foals, one male and one female, presented with respiratory difficulty, brachygnathia and failure to rise after birth. Both foals were mildly anemic, hypogammaglobulinemic and had elevations in serum alkaline phosphatase. Increased medullary bone opacity was noted on radiographs of the extremities, spine and skull in both foals. A lack of normal cortical:medullary bone distinction was evident radiographically. The medullary primary spongiosa appeared to run in parallel columns away from the physes of all long bones and the vertebrae. This created a distinctive hour glass appearance to the osteopetrotic bones. One foal developed a bacterial pneumonia. Both foals were euthanized due to failure to thrive. Histopathology and electron microscopy documented these foals to have normal osteoclastic numbers but lack normal ruffled borders, lack of a clear zone and normal lysosomal numbers indicative of cellular dysfunction. These clinical, radiographic and pathologic findings are similar to the juvenile, lethal autosomal recessive form of osteopetrosis described in humans. Osteopetrosis has not been previously described in a female foal.     

Lethal osteogenesis imperfecta and skin fragility in newborn New Zealand Romney lambs

Osteogenesis imperfecta and skin fragility occurred in about 50 New Zealand Romney lambs born in a flock of 450 ewes. Affected lambs had soft bones and multiple intrauterine bone fractures. Long bones had a thickened diaphysis with almost complete absence of a medullary cavity. Other consistent gross findings were moderate brachynathia inferior, subcutaneous oedema, marked joint laxity, dark blue sclera and small pink teeth. Histopathologic and ultrastructural changes were consistent with a defect in collagen production by fibroblasts. DNA finger-printing was used to identify which of the five rams used in the flock was carrying the genetic defect. The disease was inherited as an autosomal dominant trait and was considered to be a new mutation in the testicular germ cell lines of this ram.     

Suspected panosteitis in a camel

CASE DESCRIPTION: A 6-month-old male Bactrian camel was examined because of a 3-week history of lameness of the left hind limb. CLINICAL FINDINGS: Lameness was initially detected in the left hind limb but resolved and was detected in the right hind limb during treatment. Lameness increased during periods of rapid growth. Radiography revealed multiple small opacities of the medullary cavity of several long bones throughout treatment. Core bone biopsies of lesions in the tibiae revealed lamellar bone with areas of loose connective tissue, osteoblasts in the medullary cavity, and periosteal new bone formation, all which were consistent with panosteitis. TREATMENT AND OUTCOME: Palliative treatment was attempted with epidural and transdermal administration of analgesics. Flunixin meglumine was administered PO, which coincided with an abrupt increase in serum creatinine concentration. Performance of multiple diagnostic bone biopsies led to remission of clinical signs of pain. CLINICAL RELEVANCE: Panosteitis should be a differential diagnosis for shifting limb lameness in young camels. Bone biopsies can be useful for diagnosis of panosteitis and possible relief of pain associated with the disease. Bactrian camels may be susceptible to the renal toxicity of flunixin meglumine, especially when dehydrated.     

Profiles of Fatty Acids in Different Bone Structures of Growing Chicks

This study was concerned with the dynamics of fatty acids in tissues involved in the growth and mineralization of the femur of Starbro chicks from 1 to 50 days of age. Four chickens that died of suffocation were obtained each day. Altogether, 400 femoral bones were studied in five age groups (I–V). Compact bone, spongy bone and articular cartilage were sampled. Lipids were extracted according to Folch and fatty acids were separated using gas chromatography. The fatty acid profile was found to change with age. Fatty acids with the highest content in bone were C_18:1, C_16:0, C_18:2 and C_18:0. The highest content of fatty acids was found in spongy bone and the lowest in articular cartilage. Several correlations were revealed between individual fatty acids. The following conclusions were drawn. (1) Fatty acid profiles in compact bone, spongy bone and articular cartilage change with age of chicks. (2) Oleic (C_18:1), palmitic (C_16:0), linoleic (C_18:2), stearic (C_18:0) and arachidonic (C_20:4) acids accounted for most of the fatty acid pool. (3) Correlations in the content of fatty acids were noted between bone structures.     

Some observations on the development of the long bones of ratite birds

Observations were made on the long bones of 16 young ratite birds (10 rheas, 3 emus and 3 ostriches), from 1-day-old to 12 weeks of age.
At hatching all long bones contained large cartilaginous cones which were continuous with the growth plates, and an osseous cortex. At one week of age ossification had commenced on the periphery of these embryonic cones and in some bones the cones had become separated from the growth plates. At 3 weeks of age the embryonic cones of cartilage were still present in the proximal and distal tibio-tarsi and narrow cartilaginous bridges connected the cones to the growth plates. Embryonic cones were not present in other long bones of this 3-week-old rhea nor in the long bones of ratites 6, 8 and 12 weeks of age. Other praecocial birds such as turkey poults and chickens have cones of embryonic cartilage in their long bones at hatching and these persist in the tibio-tarsi till one to 2 weeks of age. The presence of large cones of embryonic cartilage in the tibio-tarsal bones of 3-week-old ratite birds is probably a normal phenomenon. Awareness of this feature is necessary for the correct differential diagnosis of the prevalent musculoskeletal disorders of ratite birds.     

Extramedullary hematopoiesis in the mandibular lymph node of simian-human immunodeficiency virus-infected rhesus monkeys (Macaca mulatta): a report of three cases

Three cases of extramedullary hematopoiesis (EMH) in the mandibular lymph nodes of rhesus monkeys, experimentally infected intravenously with a chimeric simian human immunodeficiency virus, are described. On histopathologic evaluation, multiple sections of mandibular lymph node from all animals showed evidence of EMH, which included erythroid, myeloid, or megakaryocytic precursor cells (or all) within the medullary sinuses. Immunohistochemistry was used for positive identification of multiple cell types. Evidence of EMH was not observed in numerous sections of axillary, inguinal, cervical, hilar, or mesenteric lymph nodes or in any other tissues examined. To our knowledge, this is the first report on EMH within the lymph nodes of rhesus monkeys without an obvious underlying disease process or stringent blood-sampling schedule warranting the need for increased hematopoiesis outside the confines of the bone marrow.     

Comparison of the trabeculae structure of the spongy bone of the bilateral pastern bones in racehorses based on the imaging analysis of radiograms

On the basis of a digital analysis of radiograms it was checked if, and to what extent, the extended loading of one of the sides of the body of racehorses leads to differences in the microstructure of the spongy bone of the bilateral pastern bones of the thoracic limbs. The research material consisted of radiograms of the pastern bones of the right and left thoracic limbs of racehorses. On the basis of computer image radiological analysis with the use of the "Trabecula,, programme, a quantative evaluation of the structure of the spongy bone of the pastern bones was conducted. It was noted that the differences between the right and the left pastern bones, despite extensive loading of the left thoracic limb, were not statistically significant as far as all studied parameters of the trabecula structure of the spongy bone were concerned.     

Effect of supplementing sows' feed with alpha-tocopherol acetate and vitamin C on transfer of alpha-tocopherol to piglet tissues, colostrum, and milk: aspects of immune status of piglets

The aim of this study was to investigate the effects of dietary supplementation of sows with alpha-tocopherol acetate (ATA) and vitamin C on deposition of alpha-tocopherol (AT) in piglet lymphoid organs, such as bone marrow, thymus, and spleen at birth and at weaning, as well as on indicators of immune response in piglets. Sows were given the following treatment diets: control, vitamin C 10 g/day, ATA 500 mg/kg feed, and combined vitamins (ATA 500+Vit-C 10). Supplementation with vitamins started at the beginning of pregnancy and lasted until weaning at 21+/-3 days of age. AT was determined in colostrum, milk, piglet plasma (cord blood) and tissues at birth and on day 21. Immunoglobulins were measured in piglet plasma, milk, and colostrum. Lymphocyte proliferation in response to PHA and ConA was determined in sow and piglet blood. ATA supplementation resulted in a significant increase (P<0.001) in the AT content of colostrum, milk, piglet plasma, liver, thymus, bone marrow, and spleen at weaning. The AT content of colostrum and milk significantly (P<0.001) influenced the AT content of piglet plasma and tissues at weaning (day 21). Total Ig and IgG concentrations in piglet plasma were significantly increased in piglets given the combined vitamin treatment. No effect of AT supplementation was observed on IgG and IgA in colostrum and milk. In sows, vitamin C given alone significantly increased lymphocyte response to ConA and PHA; whereas, in piglets, there was no significant effect of treatments on lymphocyte response to PHA and ConA.     

Measurement of Bone Growth in Osteopetrosis

Day-old chicks were injected with 0.2 ml. of a suspension of lymphomatosis virus which was known to cause osteopetrosis in a high percentage of susceptible birds. A comparable number of uninoculated chicks were kept for controls. Alizarin red S was administered for the purpose of marking the bones in order to measure the rate of growth of normal bone and the osteopetrotic bone. The dye was given at 27, 41 and 55 days of age. In this experiment it was found that a layer of normal bone was formed on the surface of the tibia at a rate of 0.25 mm. per week but in the largest osteopetrotic lesion that was found in any chicken spongy bone was formed at a rate greater than 1 mm. per week.

Alizarin red S was irritating to tissue and was toxic when given intravenously.

     

Osteopetrosis in cats

Osteopetrosis was found in two adult cats, radiographically characterised by a ‘marble bone’ appearance of the axial skeleton and of the subchondral bone of all joints, and endosteal thickening of the cortex of long bones. Computer tomography and histological assessment revealed massive endosteal lamellar bone formation. Bone resorption was still apparent, though only atypical mononuclear osteoclasts were seen. Histological findings support the assumption that the disorder was acquired. Severe anaemia was found in one cat. In the other, no clinical abnormalities were present. The condition appears to be different from feline leukaemia virus-induced medullary osteosclerosis described by Hoover and Kociba (1974).     

Development of the navicular bone in foetal and young horses, including the arterial supply

A macroscopic, arteriographic and histological study of the development and the arterial anatomy of the navicular bone of 33 foetuses and 55 young horses is described. After 125 days of gestation the blood supply consists of two routes: one situated in the superficial layer of the fibrocartilage and the other similar to the blood supply of the navicular bone of the normal mature horse. After 270 days gestation, the blood vessels in the fibrocartilage gradually regressed and retracted until they have disappeared at six months after birth. At two months after birth the first macroscopic thinning of the fibrocartilage was noticed. From seven months to one year about 45 per cent of the navicular bones showed a slight thinning of the fibrocartilage. A positive correlation was found between radiographic abnormalities (ie enlargement of the nutrient foramina) and the frequency of thinning of the fibrocartilage. Radiographic abnormalities were first recognised 14 days after birth, whereas the arteriogram showed the first changes such as fewer or no arteries entering distally at the distal extremities at 10 weeks after birth. At four weeks after birth the first arterial wall changes were found, ie intimal thickening with or without splitting of the internal elastic membrane. From that age onward, the number of navicular bones with arterial wall changes gradually increased. Starting at five months after birth only 6 to 20 per cent of the arteries in the navicular bones without radiographic abnormalities showed arterial wall changes. However, the navicular bones with radiographic abnormalities showed arterial wall changes in 25 to 80 per cent of the arteries.     

Differences in bone mineral content and density between male and female budgerigars (Melopsittacus undulatus) during the non-reproductive season

It is known that female birds increase medullary mineral stores in long bones shortly before egg laying. Here, we present results from two groups of budgerigars, in both of which females had significantly higher bone mineral contents and densities, as measured by peripheral quantitative computed tomography of the tibiotarsus, during a reproductively dormant period. The results could indicate that female birds can accumulate mineral stores outside of the breeding season.     

Hyperostotic bone disease in a wombat (Vombatus ursinus)

Little is known about wombat diseases in general, and about their congenital diseases in particular. In the current study, the skeleton of a common wombat (Vombatus ursinus) that exhibited generalized hyperostosis is analyzed, and possible diagnoses are reviewed. Macromorphological analyses revealed that the diaphyses of the long bones manifested an increased diameter with extensive diaphyseal new-bone formation (periosteal and endosteal). Cross-sections of the diaphyses showed that the cortical–medullary demarcation was indistinct. The calvarial bones were thickened. Radiographs showed uniform sclerosis of the long bones with loss of trabecular pattern. Microradiography showed extensive bone remodeling, a hyper-vascularized lamellated layer of bone and numerous linear formation defects. Possible causes for the lesions, including sclerosing bone dysplasia disorders, acquired syndromes causing hyperostosis, and metabolic diseases typical of animals in captivity, are discussed.     

Computed tomographic and radiographic morphology of the pastern and coffin joints of One-Humped Camel (Camelus dromedarius)

The objective of the current study was to describe the structures of the pastern and coffin joints in dromedary camel using x-ray, bone and soft tissue windows computed tomography (CT) and three-dimensional volume rendering (3DVR) of CT imaging. 3DVR of CT was obtained at the slight flexed dorsal view, plantar view, dorsolateral view and lateral view which explained all the surfaces and structures of the digit bony parts even the parts of the articular surface. The processed images of 3DVR of CT showed different patterns of the cortical, cancellous, subchondral bones and medullary cavity of the bones of the digits. The present study showed clearly all the hard and soft tissues in the pastern and coffin joints of the camel in CT images; however, the plantar ligaments of the pastern joint and ligaments of the navicular cartilage identified on CT images. The CT soft tissue window visualized the joint cavity and their pouches and tendon sheath of the flexor tendons better than the bone window CT. The radiographic, CT and 3D images could be used as a normal reference for the interpretation of some clinical diseases in the pastern and coffin joints of the camel.