Dermoid sinus type IV associated with spina bifida in a young Victorian bulldog

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.

Surgical management of a dermoid cyst with mandibular gland tissue in a Japanese Black calf

A 131-day-old male Japanese Black calf presented with a swollen right cheek from birth. Imaging examination revealed a cyst under the right buccal area and debris-containing fluid inside the cyst, and puncture aspiration revealed a mildly cloudy fluid containing hair and tissue fragments. Histological examination of the excised cyst revealed stratified squamous epithelium with skin appendages in the cyst wall, which was diagnosed as a dermoid cyst. In addition, some submandibular gland tissue was found within the cyst wall. After removal of the cyst, there was swelling in the same area, which resolved with steroid administration. Surgical treatment of buccal dermoid cysts should be performed with caution to avoid damage to adjacent salivary gland tissue.

Dermatological Problems of Brachycephalic Dogs

Brachycephalic dogs are not only affected by brachycephalic obstructive airway syndrome (BOAS), but are also frequently referred to veterinary dermatologists for skin conditions, with English bulldogs and pugs particularly over-represented. Some skin diseases, such as skin fold dermatitis, are directly associated with the abnormal anatomic conformation of brachycephalic dogs, while for others, such as atopic dermatitis and viral pigmented plaques, there is an underlying genetic basis or a general predisposition. Anatomic alterations associated with brachycephaly, leading to fold formation of the skin and stenosis of the ear canal, together with primary immunodeficiencies described in some breeds, favor the development of pyoderma, Malassezia dermatitis, and otitis externa/media. In addition, the frequently neglected but often lifelong dermatological problems of brachycephalic dogs are an important consideration when discussing genetic and medical conditions affecting the welfare of those dogs. Here we review the current state of knowledge concerning dermatological problems in brachycephalic dogs and combine it with clinical experience in the management of these challenging disorders.

Case Report: Surgical Treatment of Type IV Spinal Dermoid Sinus in a Shiba Inu

A 2-year-old spayed female Shiba Inu was presented with progressive non-ambulatory bilateral paraparesis, back pain, and urinary incontinence. CT and MRI revealed multiple vertebral malformations and type IV dermoid sinus. Hemilaminectomy was performed in T1–T5 to remove the dermoid sinus and granulomatous lesion that infiltrated into the spinal cord parenchyma. Histopathological examination of the excised tissue revealed type IV dermoid sinus with granulomatous meningomyelitis. After surgery, back pain was resolved, and the dog recovered ambulation and voluntary urination at the time of follow-up 4 months after surgery.

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.

Computed Tomography for the Diagnosis and Characterization of Dermoid Sinuses in Two Dogs

A 6 mo old male castrated bloodhound-Rhodesian ridgeback mix (case 1) presented for a mass suspected to be a dermoid sinus in the thoracolumbar region, and a 2.5 yr old male castrated Rhodesian ridgeback (case 2) presented for a mass suspected to be a dorsal cervical dermoid sinus. Both dogs underwent single-phase contrast computed tomography (CT) to characterize the extent of the dermoid sinus prior to surgical excision. Soft tissue and bony abnormalities of the vertebral spine associated with the dermoid sinuses were confirmed in both dogs prior to surgery, demonstrating communication with the dura of the spinal cord. Surgical exploration and excision of the dermoid sinus was performed in each dog, including partial laminectomy. Both cases had resolution of the sinus and an uncomplicated recovery. These cases show that single-phase contrast CT was accurate in characterizing the extent of the dermoid sinus without adjunctive tests or more invasive diagnostics. Single-phase contrast CT should be considered as a preoperative method to characterize the extent of dermoid sinuses, avoiding the risks associated with myelography or fistulography and the expense of MRI. This is also the first report of a dermoid sinus in the thoracolumbar region and the first in a bloodhound and Rhodesian ridgeback mix.

Dermoid sinus type VI associated with spina bifida and tethered cord syndrome in a French Bulldog

A 4-mo-old French bulldog was presented with acute onset pain and reluctance to move. A tubular structure arising in the dorsal thoracic midline and extending from a cutaneous orifice into deeper tissues was palpated on physical examination. Computed tomography with sinography revealed a dermoid sinus associated with spina bifida at the level of T3-T4. On surgical exploration, the dermoid sinus was found to communicate with the dura. Histology confirmed the diagnosis and classification as a type VI dermoid sinus. The pain response and hyperesthesia were suspected to be the result of tethered cord syndrome. Complete resolution of clinical signs was appreciated post-surgery, with the patient still free of clinical signs 3 mo later.

Congenital Malformations Resembling VACTERL Association in a Golden Retriever

A 2 mo old golden retriever presented with malformation of the left thoracic limb and a small circular indentation of the skin in the cranial thoracic spine. Radiographs showed a cleft between the second and fifth metacarpal bones of the left thoracic limb compatible with ectrodactyly and spina bifida affecting T4 and T5 vertebrae. Magnetic resonance imaging of the thoracic spine showed dorsal reposition of the spinal cord and a tract connecting from the dura mater to the skin. No other malformations were detected. Surgical excision of the tract was performed and histopathological examination diagnosed a dermoid sinus type IV. Dermoid sinus and spina bifida are well-recognized congenital spinal and spinal cord defects, yet association with other congenital malformation are rarely reported in dogs. The here-reported dog had spinal and spinal cord abnormalities with concurrent limb malformation, which are two components of a nonrandom association of birth defects described as VACTERL in people. To the authors' knowledge, this is the first report describing concurrent dermoid sinus type IV, spina bifida, and ectrodactyly in a dog, and highlights the importance of patient examination for occurrence of multiple malformations to provide an appropriate prognosis for an owner.

Spinal dermoid sinus in a Dachshund with vertebral and thoracic limb malformations

BACKGROUND

Dermoid sinus is an uncommon epithelial-lined fistula that may be associated with vertebral malformations. In humans, Klippel-Feil syndrome (KFS) is a rare condition characterized by congenital cervical vertebral fusion and may be associated with other developmental defects, including dermoid sinus. The present case report describes an adult Dachshund with cervical and cranial thoracic vertebral malformations as well as thoracic limb malformations resembling KFS with a concurrent type IV dermoid sinus.

CASE PRESENTATION

A 1.5 year-old Dachshund with congenital thoracic limbs deformities and cervical-thoracic vertebral malformations presented with cervical hyperesthesia, rigidity of the cervical musculature and tetraparesis. Neurologic, radiographic, and computed tomography (CT) (2D, 3D, CT fistulography) examinations revealed skeletal anomalies, a dermoid sinus in the cranial thoracic region and epidural gas within the vertebral canal. Surgical resection and histopathological evaluation of the sinus tract were performed and confirmed a type IV dermoid sinus. The clinical signs progressively recovered postoperatively, and no recurrent signs were observed after 6 months of follow-up.

CONCLUSIONS

Cervical vertebral malformations associated with limbs anomalies have not been reported in dogs and may represent a condition similar to KFS in humans. KFS can occur concurrently with other congenital conditions including dermoid sinus and should be included among the complex congenital anomalies described in dogs.

Multiple dermoid sinuses of type Vb and IIIb on the head of a Saint Bernard dog

Dermoid sinus, a congenital malformation of neural tube development, has been reported in humans and several animal species including dogs. It is typically found in the dorsal midline and commonly occurs in the Rhodesian Ridgeback breed. A case of multiple dermoid sinuses in the fronto-occipital region is described. An 11-month-old, intact female Saint Bernard dog was presented with a 2 day history of discharge from a large irregular subcutaneous mass in the fronto-occipital region. The dog was otherwise healthy. The dog had two circular skin lesions (approximately 4 × 4 and 4 × 2 cm diameter) surrounded by multiple irregular elevated masses. The masses had multiple small openings on the skin surface with tufts of hair protruding from the apertures. The masses were surgically removed, and the diagnosis of multiple dermoid sinuses was confirmed by histological examination. Histopathological examination showed multiple, variably sized, spherical to tubular cysts expanding the dermis and subcutis. Cysts were filled with hair shafts and lamellar keratin and were lined by a stratified squamous epithelium. Sebaceous and apocrine gland adnexal structures were also observed. To the best of our knowledge, this is the first reported case of multiple dermoid sinuses of two different types in the head of a Saint Bernard dog.