Ventriculomegaly in Cavalier King Charles Spaniels with Chiari-like malformation: relationship with clinical and imaging findings.

The objective of this study was to calculate lateral ventricles dimension in Cavalier King Charles Spaniel dogs with Chiari-like malformation and investigate the association between ventriculomegaly and signalment, clinical signs, ventricular asymmetry, grade of Chiari-like malformation, syringomyelia and index of medullary kinking. Retrospectively, 43 client-owned Cavalier King Charles Spaniels, older than 1 year of age, with magnetic resonance imaging diagnosis of Chiari-like malformation were enrolled. Initial and follow-up (up to 36 months) clinical status was graded. Images were reviewed to quantify the enlargement of lateral ventricles, evaluate ventricular symmetry, grade of Chiari-like malformation, grade of syringomyelia and medullary kinking index. Cases presenting epileptic seizures during the evaluation period were also recorded. The most common initial clinical signs were scratching and neck pain. Ventriculomegaly was identified in 70% of dogs, Chiari-like malformation grade 2 was observed in 77% of cases, ventricular asymmetry and syringomyelia were identified in 54% and 80% of dogs, respectively; the median medullary kinking index was 37.77%. Moreover, 28% of dogs presented epileptic seizures. No significant association was identified between dimension of lateral ventricles and signalment, clinical signs, and imaging findings; no significant association was identified between ventriculomegaly and epilepsy (P≥0.05). In conclusion, the prevalence of ventriculomegaly in Cavalier King Charles Spaniels is high but this finding does not seem related to the severity of clinical signs, presence of Chiari-like malformation, syringomyelia and craniocervical junction abnormalities such as medullary kinking.

Hypertrophic scar in a dog: histological and clinical features.

An adult male bullmastiff dog was treated for paraparesis and ataxia due to discospondylitis and disc herniation. At this time, the dog had a nonhealing ulcer between the pads of the left hindfoot. At re-evaluation, the dog had developed a large exophitic mass in the previously ulcerated area. Cytological examination revealed occasional spindle cells with mild atypia, and a soft tissue tumour was suspected. The mass was excised and submitted for histology. The lesion was characterized by superficial ulceration, an intermediate layer of granulation tissue and a deep portion containing vertically orientated capillaries and perpendicularly arranged fibroblasts and collagen. The histological features led to a diagnosis of hypertrophic scar. Eight weeks after surgery, the lesion recurred and was treated with an intralesional injection of methylprednisolone acetate. The lesion regressed in 10 days, but recurred after 3 months following severe self-trauma. Hypertrophic scars and keloids are two types of exuberant scarring reported in human beings, the pathogenesis of which is still unclear but seems to involve several cytokines, growth factors and inflammatory cells. The histological features identified in this case paralleled those reported in hypertrophic scars in humans. In this case, intralesional corticosteroid therapy was useful in the management of the lesion, but the severe self-trauma could have influenced the recurrence. Even if uncommon, hypertrophic scar should be included among the differential diagnoses of spindle cell tumours in dogs.

Agreement of surgeon's perception of the effectiveness of spinal cord decompression with findings on postoperative magnetic resonance imaging for dogs surgically treated for intervertebral disk extrusion.

OBJECTIVE: To determine the accuracy of the surgeon's perception versus postoperative MRI findings in assessing the effectiveness of spinal cord decompression achieved in dogs surgically treated for intervertebral disk extrusion (IVDE) and whether postoperative MRI findings were more likely to be associated with various outcomes. ANIMALS: 68 dogs surgically treated for cervical or thoracolumbar IVDE. PROCEDURES: Data on clinical, neurologic, pre- and postoperative MRI, and intraoperative findings as well as outcomes and recovery times (6-month follow-up period) were prospectively collected and compared between various groups. RESULTS: 54 (79%) dogs had thoracolumbar IVDE, and 14 (21%) had cervical IVDE. Median degree of spinal cord compression as assessed on transverse T2-weighted MRI images was 45.6% before surgery and 8.8% after surgery. The correlation between surgeons' perception (n = 3) and postoperative MRI findings for the degree of spinal cord decompression achieved was only fair (κ = 0.40). Unsatisfactory spinal cord decompression as assessed via postoperative MRI was associated with severity of preoperative neurologic grade and preoperative compression, thoracolumbar (vs cervical) IVDE, and ventral (vs ventrolateral or dorsolateral) circumferential distribution of extruded material. Satisfactory (vs unsatisfactory) decompression as assessed via MRI was associated with a lower postoperative neurologic grade, greater likelihood of a successful outcome, and lower mean recovery time. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that for dogs surgically treated for IVDE, the surgeon's perception of adequate spinal cord decompression may be less reliable than postoperative MRI findings. Postoperative MRI appeared particularly useful for dogs with a severe preoperative neurologic status, severe preoperative spinal cord compression, and thoracolumbar IVDE.