Lumbar Myelopathy Caused by Multiple Cartilaginous Exostoses in a Dog.

A 6-months-old male mixed-breed dog was admitted to the veterinary hospital with lameness in the right pelvic limb, proprioceptive ataxia, and suspected spinal cord injury in the lumbosacral segment. Upon palpation, firm nodules were noted on the bony surface of the thoracic and pelvic limbs, ribs, vertebrae, and tail. The radiographic study showed nodules of low radiopacity with well-defined limits and smooth contours, one of which was overlapping the fifth lumbar vertebra. Given the clinical presentation indicative of spinal cord injury, the animal was subjected to hemilaminectomy for nodular resection. Histopathological examination of the biopsy enabled the diagnosis of osteochondroma. The clinical follow up after surgery showed improvement in walking, despite persistent monoparesis in the right pelvic limb. The radiographic study in association with clinical and histopathological exams allowed the diagnosis and monitoring of the lesions.

Multiple cartilaginous exostoses in a Swiss Mountain dog causing thoracolumbar compressive myelopathy.

BACKGROUND: Multiple cartilaginous exostoses are a rare, benign, proliferative condition of cartilage and bone. They can be asymptomatic, or they may cause pain, lameness, paresis and even paralysis, depending on their location and size. In cases of spinal cord or nerve root compression, surgery is the treatment of choice. Therefore, an advanced imaging diagnostic work-up is indicated. Due to the unclear pathophysiology and progression of this condition, it is difficult to predict its prognosis. CASE PRESENTATION: A 9-month-old female Swiss Mountain dog was presented with a history of gait abnormalities, kyphosis and hypersensitivity consistent with a thoracolumbar myelopathy. Multiple calcified masses, most prominent at the Th7-Th9 level and the L2-L3 level, were observed. Magnetic resonance imaging of the thoracolumbar vertebral column revealed severe dorsal spinal cord compressions near the dorsal arch of the Th7-Th9 and L2-L3 vertebrae. Two of these masses were removed surgically. The successful removal of both masses was confirmed by postoperative computed tomography. The histopathological examination of the resected tissue revealed multiple cartilaginous exostoses. The first neurological and magnetic resonance follow up examination carried out 6 months postoperatively showed improvement of the clinical status. At that time, no mass regrowth was observed. The last follow up neurological examination carried out 15 months postoperatively showed gait improvement and resolution of pain. CONCLUSION: This is the first case report of multiple cartilaginous exostoses with a complete pre- and postoperative evaluation and a 15 month follow-up.

Osteochondromatosis (multiple cartilaginous exostoses) in an immature killer whale Orcinus orca.

An immature killer whale Orcinus orca found dead on the southeastern Brazilian coast had multiple bone proliferations: on the skull, vertebrae, hemal arches, and ribs. The bony formations were characterized as multiple osteochondromas, as defined by osteochondromatosis. The diagnosis was based on macroscopic and radiographic observations. These benign osseocartilaginous tumors affect young individuals and grow until skeletal maturity is achieved. Case reports of this condition, besides humans, include other mammals, with most reports for pets and domestic mammals such as cattle, and a report in a fossil canid (Hesperocyon) from the Oligocene. The etiology, diagnosis, developmental characteristics, and occurrence of osteochondromas are distinct among different species. This report describes the first case of multiple osteochondromas in a wild cetacean.

Imaging diagnosis: Multiple cartilaginous exostoses and calcinosis circumscripta occurring simultaneously in the cervical spine of a dog.

An 8-month-old female Saint Bernard dog was presented with gait abnormalities consistent with a left-lateralizing cervical myelopathy. Imaging revealed a large, irregular soft tissue and mineral mass at the level of C1 and C2. The lesion was successfully excised, and histopathology was performed, revealing evidence of both multiple cartilaginous exostoses and calcinosis circumscripta. To the authors' knowledge, this is the first report comparing features using magnetic resonance imaging, computed tomography, and radiography. Additionally, multiple cartilaginous exostoses have not previously been reported to occur in combination with calcinosis circumscripta.

An extended outbreak of congenital chondrodysplasia in calves in South East Australia.

OBJECTIVE: To report an outbreak of congenital chondrodystrophy in calves in South East Australia. METHODS: District veterinarians investigated reported cases of calf deformities. Owners of affected herds were interviewed using a standard questionnaire to identify potential risk factors. Dams of several affected calves were serologically tested for Akabane virus, Aino virus, pestivirus and bluetongue, and affected calves were tested for pestivirus antigen and serum immunoglobulin concentrations. Gross and histopathological examinations of numerous calves were performed, concentrating on the musculoskeletal system. RESULTS: A case definition of distinctive skeletal deformities was established, and 89 property owners reported calves with chondrodystrophy in Spring 2003, 2004 or 2005. Some 14 property owners reported affected calves in more than one year. Prevalence and severity of deformity varied greatly between and within properties. None of breed, sex, age of dam, lineage, pasture type, supplementary feeding, fertiliser use or toxic plants was consistently associated with the disease. All dams experienced hot, dry conditions during the first trimester of pregnancy and were exposed to adverse conditions thereafter. Consistently dams were reported to have been grazing undulating to hilly terrain during early pregnancy. All serological tests were negative for Akabane virus, Aino virus, pestivirus and bluetongue. Histopathology of affected skeletal samples showed chondrodysplasia. CONCLUSION: The outbreak had similarities with previous outbreaks reported in the region. No specific aetiology could be determined. There is some evidence that the cause of the deformities could be a manganese deficiency during foetal development. Ongoing work to test this hypothesis is therefore warranted.

A single-base change in the tyrosine kinase II domain of ovine FGFR3 causes hereditary chondrodysplasia in sheep.

Ovine hereditary chondrodysplasia, or spider lamb syndrome (SLS), is a genetic disorder that is characterized by severe skeletal abnormalities and has resulted in substantial economic losses for sheep producers. Here we demonstrate that a non-synonymous T>A transversion in the highly conserved tyrosine kinase II domain of a positional candidate gene, fibroblast growth factor receptor 3 (FGFR3), is responsible for SLS. We also demonstrate that the mutant FGFR3 allele has an additive effect on long-bone length, calling into question the long-standing belief that SLS is inherited as a strict monogenic, Mendelian recessive trait. Instead, we suggest that SLS manifestation is determined primarily by the presence of the mutant FGFR3 allele, but it is also influenced by an animal's genetic background. In contrast to FGFR3 mutations causing dwarfism in humans, this single-base change is the only known natural mutation of FGFR3 that results in a skeletal overgrowth phenotype in any species.

Inherited chondrodysplasia in Texel sheep.

CASE HISTORY: A skeletal disease characterised by dwarfism, limb deformity and sometimes sudden death occurred over a period of 5 years in lambs born on a commercial sheep farm in Southland. The disease showed variable expression and occurred in crossbred sheep. A genetic aetiology was supported by the birth of affected lambs over two seasons in a flock of putative carrier and affected sheep transported to Massey University. CLINICAL FINDINGS: Affected lambs appeared normal at birth but showed evidence of dwarfism, wide-based stance and exercise intolerance as early as 1 week of age. Most died within the first 3 months of life, often after developing bilateral varus deformity of the forelimbs. Some severely-affected lambs died suddenly of respiratory embarrassment, probably due to tracheal collapse. Mildly-affected individuals had a short, blocky stature and some survived to breeding age. PATHOLOGICAL FINDINGS: Gross and microscopic lesions of variable severity were present in the tracheal, articular, epiphyseal and physeal cartilages. In severe cases, articular cartilage in major joints was eroded from weight-bearing surfaces. The trachea was flaccid, abnormally kinked, and had thickened cartilaginous rings and a narrow lumen. Affected sheep that survived to breeding age eventually developed severe degenerative joint disease. Histologically, chondrocytes were disorganised, surrounded by concentric rings of abnormal fibrillar material, and the matrix often contained focal to coalescing areas of chondrolysis. DIAGNOSIS: Inherited chondrodysplasia of Texel sheep. CLINICAL RELEVANCE AND CONCLUSIONS: This chondrodysplasia differs from those previously described in sheep and is considered to be a newly-recognised, recessively-inherited genetic disease of the Texel breed. A defect in the synthesis of glycosaminoglycans in cartilage matrix is suspected. This disease of sheep may provide a suitable model for studying various forms of therapy for human chondrodysplasias.

Multiple cartilaginous exostosis in a Golden Retriever cross-bred puppy. Clinical, radiographic and backscattered scanning microscopy findings.

Multiple cartilaginous exostosis was diagnosed in a six-month-old Golden Retriever cross-bred male with a history of forelimb lameness and isolated, but very painful, acute episodes. Physical examination revealed a right forelimb lameness with a firm, painful palpable mass on the cranial aspect of the forearm. The radiological examination showed the presence of bony masses at the humerus and radius as well as several masses in the ribs and spinous processes of the thoracic vertebrae. Based on the history and radiographic findings, multiple cartilaginous exostosis was diagnosed. Treatment with non-steroidal anti-inflammatory drugs was commenced for two weeks without any effect. Due to the lack of a response to the treatment as well as to the progressive physical deterioration of the animal, the owners requested euthanasia of the dog. Histology of the different exostoses demonstrated the presence of a hyaline cartilage cup surrounding a central area, formed mainly by bone and cartilage trabecullae. Signs of malignancy were not observed. Back-scattered scanning electron microscopy (BEI-SEM) study revealed well ordered and progressively calcified cartilage trabecullae present underneath the non-calcified cartilage cap. At a greater depth, those cartilage trabecullae became osteochondral trabecullae, and the innermost were formed exclusively by woven and lamellar bone. The histological and back-scattered electron scanning microscopy results conclude that it was a well-arranged normal endochondral ossification process that followed a centripetal pattern inside the bony mass, confirming the diagnoses of multiple cartilaginous exostoses.

Construction of YAC/BAC contig map for the BTA 6q21 region containing a locus for bovine chondrodysplastic dwarfism.

To characterize the bovine chromosome 6q21 for bovine chondrodysplastic dwarfism (BCD), we developed 48 new microsatellite markers from yeast artificial chromosome (YAC) and bacterial artificial chromosome (BAC) clones using a modified magnetic bead capture method. These new markers were used to construct a high-resolution physical map of the region with a total of 85 loci. The physical map will be a powerful tool for successful positional cloning experiments.

Canine multiple cartilaginous exostoses: unusual manifestations and a review of the literature.

Multiple cartilaginous exostoses were diagnosed in a two-year-old Great Dane and a four-month-old border collie. Clinically, the Great Dane showed only mild discomfort, while the border collie exhibited tetraparesis due to cervicothoracic compression. Unusual features in the Great Dane were exostoses that bridged physes, with progression after skeletal maturity. The border collie puppy's exostoses resembled tumoral calcinosis radiographically. Limb exostoses in this puppy often were para-articular, and most were not attached to the underlying bone. These features resembled metachondromatosis in humans. Analysis of previously reported cases of multiple cartilaginous exostoses indicated that the prognosis is guarded to poor.

Resolution of lameness associated with Scottish fold osteodystrophy following bilateral ostectomies and pantarsal arthrodeses: a case report.

Bilateral hind-limb lameness, associated with tarsal exostoses in a Scottish fold diagnosed as having Scottish fold osteodystrophy, resolved following staged bilateral ostectomies and pantarsal arthrodeses. Degenerative changes in the phalangeal joints of the hind limbs have progressed radiographically, but lameness has not recurred 48 weeks following the second arthrodesis. Additional skeletal abnormalities were detected radiographically in both carpi and in several caudal vertebrae. A partial, left-sided conduction deafness was diagnosed by evaluating brain stem auditory-evoked responses.

Insulin-like growth factor-I levels and gene expression in ovine hereditary chondrodysplasia (spider lamb syndrome).

Hereditary Chondrodysplasia or Spider Lamb Syndrome (SLS) is an inherited, semi-lethal, musculo-skeletal disease affecting lambs primarily of Suffolk or Hampshire breeding. Deformities of the limbs and spinal column along with multiple sites of ossification at the anconeal process are diagnostic for the disease. Muscle atrophy is also predominant. We have investigated the relationship between SLS and circulating levels of IGF-I and the IGF-BPs in older (50-80 d of age) animals. Serum IGF-I levels were lower (P less than 0.01) in SLS affected lambs (117 ng/ml) than in phenotypically normal lambs (188 ng/ml) while serum levels of the 32 kDa BP increased (P less than 0.01) 77% in SLS affected lambs as compared to contemporary controls. All other IGF-BPs appeared to be unaffected in this group. Gene expression of IGF-I and -II in the liver and muscle of younger (16-22 d of age) lambs was also measured. There were no differences in IGF-II expression in either muscle or liver between SLS affected and phenotypically normal control lambs. Muscle IGF-I expression also did not differ. However, liver IGF-I expression in SLS affected lambs was nearly double that of control lambs (P less than 0.01). These data suggest that the regulation of IGF-I and the IGF-BPs may be involved in the physical manifestations of this disorder.

[Multiple enchondromatosis in dogs. Pathologico-anatomic and histologic findings, discussion of pathogenesis]. / Multiple Enchondromatose beim Hund. Pathologisch-anatomische und -histologische Befunde, Diskussion der Pathogenese.

Data is presented of the post-mortem macroscopic and microscopic examination of two Toy Poodles with multiple enchondromatosis (Ollier syndrome). In both animals opening and maturation disorders of the growth plates were found in several skeletal locations. Due to the dogs' age difference at necropsy (14 and 4 months), some variation was also present in occurrence and appearance of primary and secondary alterations, which gave rise to some conclusions regarding development and progression of the disease. Chondrodysplasia, a characteristic of several breeds, is considered to be the essential factor in the pathogenesis of multiple enchondromatosis in the described cases.

Case report 622. Multiple cartilaginous exostoses.

The case is presented of multiple cartilaginous exostoses involving the right and left metatarsals and phalanges, left scapula, ends of several distal ribs, and the spinous processes of several thoracic and lumbar vertebrae in a 3-month-old female Scottish terrier dog. Radiographical studies showed circumscribed expansile lesions in the affected bones. The dog developed neurological deficits 3 weeks later. Myelography displayed extradural compression of the opaque column at several thoracolumbar vertebrae. The biopsy specimen from an affected phalanx consisted of trabecular bone and hemopoietic tissue covered by a thin cap of hyaline cartilage. The dog was euthanized due to the poor prognosis. At autopsy, the surface of the affected bones was covered by a bluish-white, smooth, undulating cartilage cap. Histopathologically, the cartilaginous cap consisted of hyaline cartilage without a reserve zone, and abnormal endochondral ossification. The hereditary nature and the malignant transformation of multiple cartilaginous exostoses in the dog have been considered.

DNA polymorphism analysis of hereditary multiple exostoses in horses.

Genomic DNA polymorphisms obtained by restriction fragment-length polymorphism from healthy horses and horses with hereditary multiple exostoses were analyzed. These DNA were digested by 12 restriction enzymes and were hybridized against 6 isotopically labeled oncogene probes. Hybridization was not detected with the viral oncogene, v-ras, which indicated this oncogene was absent in the equine genome. Oncogenes (c-raf-1, c-fes, c-myb, c-myc, and c-sis) were present and had similar hybridization patterns and signal intensities in DNA from healthy horses and horses with hereditary multiple exostoses. Unique and distinct restriction fragment-length polymorphisms were detected with the c-raf-1 probe only in BamHI- and PstI-digested equine DNA.

Comparison of G-banded chromosomes from clinically normal lambs and lambs affected with ovine hereditary chondrodysplasia (spider syndrome).

Lymphocytes from 5 clinically normal lambs and 5 lambs affected with ovine hereditary chondrodysplasia (spider syndrome) were cultured, G-banded, and karyotyped. Fifty metaphase karyotypes and one heterogram were evaluated for chromosome number and morphologic features. All lambs had normal diploid (2n) chromosome numbers of 54,XX or 54,XY, and there were no apparent differences in the morphologic features of the chromosomes.