ObjectiveTo determine the accuracy of pedicle screw placement in the thoracic spine of dogs with spinal deformities with three‐dimensionally (3D) printed patient‐specific drill guides.Study designRetrospective study.Sample populationSix dogs in which sixty pedicle screws were placed in the thoracolumbar spine.MethodsMedical records were searched between June 2017 and June 2018 for dogs with clinical signs associated with a thoracolumbar vertebral malformation. Inclusion criteria included MRI and computed tomography (CT) data that were used to create 3D printed patient‐specific drill guides. All dogs were stabilized dorsally with guided bicortical pedicle screws and polymethylmethacrylate. Accuracy of screw placement was assessed by immediately postoperative CT according to a modified Zdichavsky classification.ResultsFive pugs and one French bulldog met the inclusion criteria. Sixty bicortical pedicle screws were placed; 96.7% were graded as I (optimal placement), and 3.3% were classified as IIa (partial penetration of the medial pedicle wall) according to a modified Zdichavsky classification.ConclusionThree‐dimensionally printed patient‐specific drill guides allowed safe and accurate placement of pedicle screws in the thoracolumbar spine in dogs with vertebral malformation.Clinical significanceThree‐dimensionally printed patient‐specific drill guides are a safe and effective method of placing pedicle screws in dogs with thoracolumbar vertebral malformations.

The use of a 3D-printed patient-specific drill guide permitted accurate placement of 32 bicortical pedicle screws in the caudal cervical vertebrae of 3 dogs. This technique may improve clinical outcome through superior biomechanical properties of screws, reduced surgical time, and reduced morbidity. These results warrant evaluation of patient outcome in a larger population.

The records of 11 dogs with evidence of meningoencephalomyelitis of unknown origin were reviewed. Two of them had had a focal form of the disease and the other nine a disseminated form. The forebrain was involved in five of the nine dogs with disseminated disease, the brainstem in all nine and the cerebellum in one. They had been treated with courses of cytosine arabinoside every three weeks and immunosuppressive doses of prednisolone. Their response to the treatment, in terms of quality of life, was judged by their owners and referring veterinarians to have been excellent in five, good in five and poor in one; their survival times ranged from 78 days to more than 603 days. The cumulative probability of survival at two years was 58.4 per cent. No signs of myelosuppression or other side effects associated with cytosine arabinoside were observed.

Dogs with fibrocartilaginous embolic myelopathy (FCEM) or acute non-compressive nucleus pulposus extrusion (ANNPE) are reported to have a fair prognosis; however, persistent motor/autonomic deficits are possible. Specific MRI patterns have been suggested to differentiate these diseases although never been validated with histopathology in large studies. The aim of this retrospective study was to evaluate if these MRI patterns are associated with different clinical outcomes in dogs with peracute non-progressive T3-L3 myelopathy. Two hundred and one dogs were included. Outcome data were obtained via medical records and telephone questionnaires. MRIs were blindly reviewed by three board-certified observers, obtaining substantial to almost perfect interobserver agreement on diagnoses (κ=0.635-0.828). Presumptive ANNPE and FCEM were diagnosed in 157 and 44 dogs , respectively. Ambulatory function was regained in 99 per cent of cases, with persistent motor deficits in 83.6 per cent and 92.5 per cent of dogs with presumptive ANNPE and FCEM, respectively. The presumptive diagnosis was not associated with motor function recovery, recovery times or urinary continence. Faecal incontinence was five times more likely in dogs with presumptive ANNPE (23 per cent) compared with presumptive FCEM (7.5 per cent).Distinguishing between MRI patterns of presumptive ANNPE or FCEM in dogs with peracute non-progressive T3-L3 myelopathy may help predict the risk of developing faecal incontinence.

No abstract

A retrospective study was performed to identify dogs with cerebrospinal fluid-filled cavitatory lesions on MRI. Six dogs were included and the lesions were classified. In the three dogs in the present study with hydranencephaly, unilateral but complete loss of the temporal and parietal lobes was noted and had almost complete loss of the occipital and frontal lobes of a cerebral hemisphere. In the three dogs with porencephaly, there was unilateral incomplete loss of the parietal lobe and one dog had additional partial loss of the temporal and frontal lobes. Two of the dogs with porencephaly had seizures; the third showed no associated clinical signs. The dogs with hydranencephaly had mentation changes and circled compulsively. The two porencephalic dogs with seizures were treated with phenobarbitone. One of the dogs with hydranencephaly showed increased frequency and duration of circling; one dog's clinical signs did not progress and the third dog was euthanased due to increasing aggression. The dog with increased circling had ventriculoperitoneal shunt placement and the circling frequency reduced.

Objective: To describe the clinical presentation, magnetic resonance imaging features, and outcome of cats treated with hemilaminectomy for intervertebral disc extrusion (IVDE). Study design: Short case series.Animals: Six cats. Methods: Medical records were reviewed for signalment, onset, duration, and severity of clinical signs, magnetic resonance imaging features, surgical findings, and clinical outcome with a minimum postoperative follow-up of 4 weeks. Results: Our population included 6 cats with a median age of 8.6 years, consisting predominantly of males (n = 5) and purebred cats (n = 4). An acute onset and short duration of progressive clinical signs of myelopathy was the most common presentation; spinal hyperesthesia was present in 3 cats. A large volume of extradural material was identified by MRI within the lumbar vertebral column of each cat, causing marked spinal cord compression. The most common sites affected were L2-L3 (n = 2) and L6-L7 (n = 2). Follow-up after hemilaminectomy was available in 5 cats: 4 had normal voluntary motor function, and 1 had recurrence of acute paraplegia, compromised nociception, and an extensive T2w hyperintense intramedullary lesion according to MRI. All 4 cats with preoperative urinary incontinence remained incontinent for at least 1 week despite good voluntary motor function of pelvic limbs. Conclusion: Intervertebral disc extrusion was diagnosed by MRI in all 6 cats, most commonly at L2-3 and L6-7. Hemilaminectomy resulted in a good to excellent outcome in 4 of 5 cats. Clinical significance: Feline IVDE can be diagnosed by MRI and carry a good prognosis after surgical decompression, although urinary continence may be delayed despite good pelvic limb voluntary motor function.

To report outcome and complications following atlanto-axial stabilisation by polymethylmethacrylate applied to screws placed using 3D-printed patient-specific drill guides. Materials and MethOds: Case series of dogs treated with this technique between May 2016 and August 2018 including pre-and post-operative modified Frankel score, imaging and complications. Screw placement was graded using a modified Zdichavsky classification based on post-operative CT. Telephone follow-up was obtained for surviving dogs. results: Twelve cases were included. At presentation, modified Frankel score was 3 in five dogs and 4 in seven dogs on presentation. Of 61 bicortical screws placed, 57 (93%) were fully contained within the pedicle and vertebral body and four (7%) partially breached the medial pedicle wall. Post-operative CT revealed good alignment of C1 and C2 in all planes. Reversible perioperative adverse events were described in five of 12 dogs and two dogs were euthanased shortly after discharge. At 18 to 50 days after surgery eight dogs had improved neurological status. Neurological status remained unchanged in the remaining two dogs. All dogs were reported ambulatory and pain-free at telephone follow-up (median 405 days post-surgery, range 180 to 780 days). clinical significance: This technique resulted in safe bicortical screw placement in dogs with atlantoaxial subluxation.