Type I and type IV dermoid sinus with associated cervical spina bifida in a Labrador Retriever mixed breed dog.

A 6-month-old female Labrador Retriever mix rescued by a local shelter developed respiratory distress and later became tetraplegic. After transferring to a specialty centre, diagnostic imaging (CT and MRI) revealed spina bifida at C3 and dermoid sinuses at the level of C3 and T1. Surgery was performed to remove the dermoid sinuses. The dog was placed on broad-spectrum antibiotics and a tapering anti-inflammatory dose of prednisone, postoperatively. Independent ambulation was regained within 14 days with no recurrence of neurologic clinical signs.

Open spina bifida characterisation in a dog foetus.

BACKGROUND: Open spina bifida is an uncommon malformation in animals, and there is a lack of imaging, clinical, and pathological characterisation of this condition in dogs. OBJECTIVE: Open spina bifida is rarely observed in animals due to high levels of perinatal mortality and frequent euthanasia. To the best of our knowledge, we present the first case of spina bifida in a dog was diagnosed in-utero and then followed post-partum. METHODS: A 3-year-old Poodle was presented with twin pregnancy. Radiographic and ultrasonographic findings were suggestive of vertebral malformation and open spina bifida with myelomeningocele in one foetus. Conservative treatment was given but the puppy died 3 days after birth. Thereafter, anatomical and histopathological analysis of several organs was performed to characterise the disease. RESULTS: When the twins were born, one puppy had a linear dorsal midline cutaneous defect extending from the level of vertebrae L2-L6. R Radiographic examination showed several congenital vertebral malformations involving the thoracic segment, lumbar segment, sacrum and scapula. Histopathological examinations confirmed the presence of open spina bifida and identified additional abnormalities in several internal organs. CONCLUSIONS: This case presents a complete characterisation of open spina bifida, before birth and after death, using imaging and histopathology techniques.

Ischemic myelomalacia and closed spinal dysraphism in multiple finishing swine.

Ischemic myelomalacia secondary to fibrocartilaginous emboli (FCE) is an idiopathic disease in humans and animals. On the other hand, congenital spinal cord malformations result from neural tube defects in fetal development (ie, spinal dysraphism), with structural anomalies referred to collectively as myelodysplasia. Spinal dysraphisms are frequently accompanied by skin and vertebral abnormalities because of the embryogenic relationship. In this observational case study, we report the pathologic findings of 13, 18- to 24-weeks-old pigs from a large conventional operation that presented with acute paraparesis. Ischemic myelomalacia secondary to FCE was observed in 5 of 13 examined pigs. Congenital spinal cord malformations located between the caudal thoracic and sacral spinal cord were identified in 7 pigs, with structural abnormalities that ranged from diplomyelia/split cord malformation to segmental spinal dysgenesis (myelodysplasia) to caudal agenesis. Concurrent myelomalacia and congenital spinal cord malformations in the same or different sites were noted in 2 pigs. No spinal lesion was observed in 3 pigs. Although gross vertebral abnormalities were not observed herein, intervertebral instability due to minor defects in the articular facets, as well as other unidentified factors, is suspected to contribute high incidence of FCE. It is likely that these congenital malformations were previously underdiagnosed or are possibly new conditions associated with continuous inbreeding and genetic improvement in the modern swine industry.

Comparison of inherited neural tube defects in companion animals and livestock.

Neural tube defects (NTDs) are congenital malformations resulting from the improper or incomplete closure of the neural tube during embryonic development. A number of similar malformations of the protective coverings surrounding the central nervous system are also often included under this umbrella term, which may not strictly fit this definition. A range of NTD phenotypes exist and have been reported in humans and a wide range of domestic and livestock species. In the veterinary literature, these include cases of anencephaly, encephalocele, dermoid sinus, spina bifida, and craniorachischisis. While environmental factors have a role, genetic predisposition may account for a significant part of the risk of NTDs in these animal cases. Studies of laboratory model species (fish, birds, amphibians, and rodents) have been instrumental in improving our understanding of the neurulation process. In mice, over 200 genes that may be involved in this process have been identified and variant phenotypes investigated. Like laboratory mouse models, domestic animals and livestock species display a wide range of NTD phenotypes. They remain, however, a largely underutilized population and could complement already established laboratory models. Here we review reports of NTDs in companion animals and livestock, and compare these to other animal species and human cases. We aim to highlight the potential of nonlaboratory animal models for mutation discovery as well as general insights into the mechanisms of neurulation and the development of NTDs.

Type IV dermoid sinus, intramedullary dermoid cyst and spina bifida in a Cane Corso.

A 1-year-old male Cane Corso was presented for progressive hindlimb neurologic deficits, with a history of suspected recurrent meningitis. Physical examination and advanced diagnostic imaging findings were suggestive of a thoracic dermoid sinus extending into the dura mater, and spina bifida. After initial medical treatment, the lesion was surgically excised, and the presence of an intramedullary cyst in continuation with the dermoid sinus was confirmed, requiring partial durectomy and myelotomy for removal. Histopathological examination of the excised tissue confirmed the diagnosis of a dermoid sinus associated with an intramedullary dermoid cyst. After surgery, the dog temporarily declined neurologically but then showed progressive neurological improvement. This report describes presentation and successful surgical treatment of a type IVa dermoid sinus associated with an intramedullary dermoid cyst and spina bifida in a dog.

Tethered spinal cord related to caudal spinal dysraphism in a tailless Holstein calf.

A rare dysraphic caudal spinal anomaly, or caudal agenesis, comprising a tethered spinal cord, was found in a tailless Holstein calf that presented ataxia and paresis with analgesia of the hind limbs. The gently and slimly tapered conus medullaris was poorly formed between S2 and S3 which indicated that it was lying more caudally. The caudal end of the filum terminale adhered to the inner periosteum of the vertebral arch at S4, which is compatible with tethering of the spinal cord. The dysraphic changes from the secondary neurulation error and the longitudinal deranged cord morphology that may have been caused by the caudad traction due to tethering were confirmed. This represents the first bovine case with definitive morphological confirmation.

Neural tube defects in four Shetland sheepdog puppies: clinical characterisation and computed tomography investigation.

BACKGROUND: Here, we report on the occurrence of neural tube defects (NTDs) in four related Shetland sheepdog puppies. NTDs present as a range of congenital malformations affecting the spine, skull and associated structures. Despite the severity of these malformations and their relatively high prevalence in humans, the aetiology is not well understood. It is even less well characterised in veterinary medicine. CASE REPORT: Affected puppies were investigated using computed tomography (CT) and then necropsy. CT identified a range of brain and spine abnormalities in the affected animals, including caudal anencephaly, encephalocele, spina bifida and malformed vertebrae. Other observed abnormalities in these puppies, including cranioschisis, atresia ani and hydrocephalus, may be secondary to, or associated with, the primary NTDs identified. CONCLUSION: This case report describes multiple related cases of NTDs in an Australian cohort of dogs. This study also highlights the potential of advanced imaging techniques in identifying congenital anomalies in stillborn and neonatal puppies. Further research is required to investigate the aetiology of NTDs in this group of affected Shetland sheepdogs.

A case of a giant mass in the lumbar region of a newborn calf.

The present report describes a newborn calf with spina bifida that presented with a giant mass of the lumbar region, as well as subsequent gross, histological, and immunohistochemical examinations. A malformed Japanese black calf (estimated weight = 20 kg) was euthanized immediately after birth. A gross evaluation revealed a giant mass (approximately 60 cm × 30 cm × 15 cm) covered by the hair coat in the lumbar region and connected with the hair coat of the trunk. The mass surface was divided by a deep polygonal groove and externally resembled a lobulated kidney. Histology and immunohistochemistry revealed that the giant mass comprised a vessel, bronchiolus lined with cuboidal epithelium, and small alveolus. Bone bleaching revealed various abnormalities, including spina bifida, vertebral fusion, vertebral deformity, vertebral malformation, vertebral scoliosis, and coxal bone malformation. Following a suggestion that the giant lumbar region mass was occupied by lung tissue, this case was considered to involve an asymmetric conjoined duplicitas that resulted in a very rare dichotomous spondylosis malformation.

Myelomeningocoele and a dermoid sinus-like lesion in a French bulldog.

A 2-year-old male French bulldog was presented for investigation of lumbosacral pain and hindlimb ataxia associated with urinary and fecal incontinence. Survey radiography, myelography, and computed tomography images were suggestive of a dermoid sinus with associated spina bifida. Surgical intervention led to a resolution of pain and neurological deficits. Histopathological analysis of the excised tissue was compatible with a myelomeningocoele of the 7th lumbar vertebra.

Méningo-myélocèle et lésion dermoïde s'apparentant à un sinus chez un Bouledogue français. Un Bouledogue français mâle âgé de deux ans a été présenté pour faire enquête sur une douleur lombo-sacrée et une ataxie des jambes postérieures associée à une incontinence urinaire et fécale. La radiographie, la myélographie et les images par tomodensitométrie pour faire enquête sur les symptômes suggéraient un sinus dermoïde avec spina-bifida connexe. L'intervention chirurgicale a donné lieu à une résolution de la douleur et des autres déficits neurologiques. L'analyse histopathologique du tissu excisé était compatible avec un méningo-myélocèle de la 7e vertèbre lombaire.(Traduit par Isabelle Vallières).

Perosomus elumbis, cerebral aplasia, and spina bifida in an aborted thoroughbred foal.

Perosomus elumbis represents a rare congenital anomaly characterized by aplasia of the lumbosacral spinal cord and vertebrae. This anomaly is often associated with arthrogryposis and malformations of the urogenital and intestinal tract. This report describes the first case of perosomus elumbis in an aborted Thoroughbred foal associated with cerebral aplasia with meningocele, cranioschisis, spina bifida, a fused urogenital and intestinal tracts lined by a cutaneous mucosa without uterine glands, atresia ani, and arthrogryposis of the hind legs. Immunohistochemistry detected no abnormalities in the GFAP, S-100, vimentin, NeuN, doublecortin, and neurofilament expression pattern in the remnants of the brainstem. Pathogenic bacteria or equine herpesviruses one and four were not found using a microbiological investigation or polymerase chain reaction, respectively. The observed malformations may be induced by a severe developmental disturbance during the formation of the neural tube with secondary distortion of the surrounding mesoderm. Although the aetiology of this dysorganogenesis remains undetermined, inherited chromosomal mutations, an intake of different xenobiotics, and/or a disturbed metabolism of the mare may have caused the defect.

Dermoid sinus and spina bifida in three dogs and a cat.

This case series describes four cases of concomitant dermoid sinus and spina bifida in a Chinese crested dog, two Swedish vallhunds and a Burmese cat. The diagnosis was confirmed by computed tomography, computed tomography fistulography and pathology. Two dogs that showed abnormalities during neurological examination underwent magnetic resonance imaging. One of them had imaging findings interpreted as syringohydromyelia. All the dogs underwent surgery and the outcome was considered good in all the cases. Based on clinical and pathological examination as well as diagnostic imaging findings, two of the dermoid sinuses were classified as type IV, and two of them showed a previously unreported type of dermoid sinus. This new type is suggested here as type VI.

Spina bifida with associated malformations of the central nervous system in Dorper-cross sheep.

CASE HISTORY: In 2008, six lambs within a flock of Dorper-cross sheep were born with musculoskeletal and neurological disease. Clinical signs included hindlimb weakness, and urinary incontinence. CLINICAL FINDINGS: All lambs had focal, inverted areas of alopecic skin over the caudal sacrum, and short, often kinked tails. Four affected lambs were subject to euthanasia, and necropsied. On gross examination, the arches of sacral vertebrae were absent, and spinal nerves and meninges were adherent to the overlying subcutis. Other gross lesions included narrow, elongated skulls, herniation of the occipital lobes into the caudal fossas, hydrocephalus, and syringomyelia. One lamb had coning of the cerebellar vermis, but cerebellar herniation through the foramen magnum was not identified. DIAGNOSIS: Spina bifida, with associated malformations of the central nervous system. CLINICAL RELEVANCE: Examination of breeding records suggested either an autosomal recessive or partially penetrant autosomal dominant pattern of inheritance. Because of the associated tail lesions it is proposed that the pathogenesis of this syndrome involves a defect in development of the tail bud (secondary neurulation), that tethering of the spinal cord resulted in the clinical signs, and abnormal pressure of the cerebral spinal fluid resulted in the defects in the skull and brain.

Imaging diagnosis--cerebellar displacement and spina bifida in a calf.

Herein, we describe a calf affected by cerebellar displacement and spina bifida, diagnosed by ultrasonography. A full-term, newborn female calf with paralysis of the pelvic limbs was examined. The dorsal skin at the sacral level contained a circular defect; this was subsequently diagnosed as spina bifida. Cerebellar displacement into the cervical vertebral canal was suspected because of the frequent association of these anomalies. Spinal ultrasound examination carried out at the level of the craniocervical junction allowed identification of herniation of the cerebellum, the caudal part of brain stem, and part of an occipital lobe into the cervical vertebral canal. The ultrasonographic diagnosis was confirmed as post mortem examination. This type of brain defect, associated with spina bifida, resembles the Arnold-Chiari malformation in humans.

Imaging diagnosis--split cord malformation.

The features of a calf with a split cord malformation are described. Clinically, there was severe cervicothoracic kyphoscoliosis and an interscapular dermal sinus associated with cerebrospinal fluid drainage. Using magnetic resonance imaging, complete duplication of the spinal cord at the cervical intumescence was detected. There was associated syringohydromyelia, multiple cervicothoracic vertebral malformations resulting in kyphoscoliosis and rachischisis, herniation of the cerebellar vermis, meningoencephalocele, and calvarial defects.

Spinal dysraphism in a newborn Holstein-Friesian calf.

Spinal dysraphism, not associated with vertebral defect or arthrogryposis, was found in a 3-day-old Holstein-Friesian calf that was clinically diagnosed as having encephalopathy. The dysraphic lesion occurred in the sixth (C6) and seventh (C7) segments of the cervical spinal cord. Microscopically, the lesion was characterized by hydromyelia, syringomyelia, anomaly of the ventral median fissure, abnormal running of the myelinated nerve fibers in the white column, and absence of the central canal due to a developmental defect of the ependymal cells.

Cervical meningomyelocele associated with spina bifida in a hydrocephalic miniature colt.

Cervical meningomyelocele, spina bifida, and hydrocephalus were diagnosed in a newborn miniature colt that was unable to stand and had a cystic mass in the caudal portion of the dorsal cervical region. Results of physical examination and ultrasonographic imaging of the brain supported the diagnosis of hydrocephalus. Results of radiographic evaluation of the vertebral column were consistent with spina bifida at C5-C6. Fluid aspirated from the cervical mass resembled CSF. Radiography of the cervical region after injection of iohexol into the mass revealed herniation of the spinal cord through a large bony defect, supporting the diagnosis of spina bifida and meningomyelocele. Meningomyelocele, spina bifida, and hydrocephalus are interrelated congenital anomalies in other species. Meningomyelocele should be suspected in foals that have neurologic abnormalities, especially if they have other congenital anomalies and a fluid-filled mass along the dorsal midline.

Malformations of the vertebral bodies and the ribs associated to spinal dysraphism without spina bifida in a Pekingese dog.

A Pekingese dog with hemivertebrae, rib malformations and spinal cord dysraphism without spina bifida was presented. Two types of hemivertebrae were seen: bilateral and unilateral. Thoracic hemivertebrae were associated with fused ribs and rudimentary ribs. Spinal dysraphism consisted of polycavitary syringomyelia in the dorsal and lateral funiculi, hydromyelia and anomalies of the dorsal median septum and median fissure, associated to lumbar and sacral hemivertebrae. Cauda equina agenesia was also present. To conclude, the dog showed two malformations from different embryonic origins. Vertebral and rib malformations are of mesodermic origin and spinal dysraphism is of ectodermic origin. A possible common mechanism responsible for both anomalies is discussed.