IV Versus Myelography Computed Tomography for Thoracolumbar Intervertebral Disc Extrusion Surgical Planning in French Bulldogs.

Accurate diagnostic imaging is required for surgical planning of acute thoracolumbar intervertebral disc extrusion. However, data comparing the accuracy of conventional IV contrast-injected computed tomography (CT) and myelography CT for hemilaminectomy localization and size assessment are sparse. In this study, IV contrast-injected CT and myelography CT were performed in 48 French bulldogs presenting with acute disc herniation and compared with postsurgical CT. CT images were evaluated by three raters. IV contrast-injected CT erroneously identified the compressive lesion site significantly more often than myelography CT. The length of the compressive lesion was significantly higher using myelography CT compared with conventional CT, but this did not lead to relevant consequences on the surgical opening site length. Myelography CT should therefore be recommended when thoracolumbar disc disease is suspected and multiple compressive lesions are visualized on IV-injected CT in French bulldogs.

Combination of Prednisolone and Azathioprine for Steroid-Responsive Meningitis-Arteritis Treatment in Dogs.

Treatment with high corticosteroid dosages for steroid-responsive meningitis-arteritis (SRMA) is correlated with severe adverse effects and worse quality of life. In order to improve immunosuppression and decrease dosage and duration of glucocorticoid treatment, a second immunosuppressive drug is commonly used in most of the immune-mediated diseases. The objective of this retrospective study was to evaluate the efficacy, tolerability, and occurrence of relapse for the combination of prednisolone and azathioprine. All dogs received azathioprine 2 mg/kg q 24 hr for 1 mo and then 2 mg/kg every other day for 2 mo; prednisolone was started at an immunosuppressive dosage and tapered off gradually during a mean of 3 mo. Twenty-six dogs met inclusion criteria. Twenty-one dogs (81%) were in clinical remission with no relapse observed within the 2 yr follow-up period. Treatment was well tolerated in all dogs and side effects were most of the time mild and self-limiting. The relapse rate (19%) was lower than most published rates. A prednisolone and azathioprine combination appeared to be effective for primary treatment of dogs with SRMA and allows a quicker tapering in prednisolone dosage, a decrease in long-term side effects of steroids, a shorter duration of treatment, and a low relapse rate.

Diagnostic Values of Clinical and Magnetic Resonance Findings in Presumptive Trigeminal Neuropathy: 49 Dogs.

The goal of this retrospective, cross-sectional study was to describe the different etiologies of trigeminal neuropathy based on clinical and MRI findings and to evaluate the significance of associated concomitant disorders. MRI studies of 49 dogs with trigeminal neuropathy were blindly reviewed and were classified into the following three groups: neoplasia, neuritis, or idiopathic trigeminal neuropathy (ITN). Thirty-one percent were suspected to have neoplasia (all unilateral), 16% to have neuritis (1 bilateral and 7 unilateral), and 53% to have ITN (4 unilateral and 22 bilateral). Dogs with clinical bilateral trigeminal dysfunction were most likely to have a diagnosis of ITN (predicted probability 95.7%). Unilateral clinical signs were significantly associated with neoplasia or neuritis compared with ITN (P < .001 and P = .002, respectively). Even with marked brainstem neoplastic involvement, central neurological deficits may be absent. Sensory impairment was significantly associated with either neoplasia or neuritis compared with ITN (P = .007 and P = .03, respectively). Ipsilateral noninfectious middle ear effusion was only seen in dogs with neoplasia (33%). Horner's syndrome was present in 12% of all dogs (2 dogs in each group). Dogs with neoplasia were significantly older than dogs with neuritis (P = .02) and ITN (P = .002). JAAHA-MS-6997.

A rare case of malignant vagus nerve sheath tumor presenting with multiple cranial nerve dysfunction in a dog.

A 5-year-old intact male Gascon Saintongeois dog was presented with a 6-month history of coughing, laryngeal paralysis, a deglutition disorder of gradual onset, and left-sided Horner's syndrome. The dog was admitted as an emergency for acute central vestibular signs. Magnetic resonance images identified a left extra-axial brainstem lesion extending caudally from the medulla to the vagosympathetic trunk. Histological and immunohistological examination revealed a high grade epithelioid malignant peripheral nerve sheath tumor (MPNST). This case report is the first description of a MPNST of the vagus nerve compressing the brainstem and causing multiple cranial nerve dysfunction in a dog. Key clinical message: Nerve sheath tumors have been reported in many locations arising from spinal nerve roots and cranial nerves. Although the trigeminal nerve is the most commonly affected nerve, other cranial nerves such as the vagus can be affected.

Un cas rare de tumeur maligne de la gaine du nerf vague à l'origine d'une dysfonction de plusieurs nerfs crâniens chez un chien. Un chien mâle entier de cinq ans de race Gascon Saintongeois a été présenté avec un historique de 6 mois de toux, paralysie laryngée, trouble de la déglutition d'évolution progressive et un syndrome de Claude Bernard Horner à gauche. Le chien a été admis en urgence pour des signes vestibulaires centraux. Une imagerie par résonnance magnétique a mis en évidence une lésion extra-axiale gauche localisée au niveau du tronc cérébral s'étendant caudalement de la medulla vers le tronc vagosympathique. Les examens histologique et immunohistologique ont révélé une tumeur épithéliale maligne des gaines nerveuses de haut grade (TMGN). Ce rapport de cas est la première description de TMGN du nerf vague comprimant le tronc cérébral et à l'origine d'une dysfonction de plusieurs nerfs crâniens chez un chien.Message clinique clé:Les tumeurs des gaines des nerfs ont été rapportées de plusieurs localisations prenant leur origine des racines des nerfs spinaux et des nerfs crâniens. Bien que le nerf trijumeau soit le nerf le plus fréquemment affecté, d'autres nerfs crâniens, tel que le vague, peuvent être affectés.(Traduit par Dr Serge Messier).

Using a three-dimensional-printed device with the patient's maxillary dental impression allows to perform minimally invasive brain biopsies in dogs and cats: a preliminary study.

OBJECTIVE: To develop an innovative process for stereotactic brain biopsies in dogs and cats that would provide a definitive diagnosis and optimize the management of patients with brain lesions. ANIMALS: 4 dogs and 1 cat diagnosed with 1 or more brain lesion(s) underwent brain biopsies between March 24, 2023, and October 25, 2023. METHODS: Based on trajectories selected on images of MRI and CT scan performed on each patient, a computerized software program was used to design a 3-D-printed patient-specific device with maxillary dental impression located on a baseplate to secure the patient's head and with insertion ports for the biopsy instrumentations located on a C-arm. As proof of concept, the device was successfully used in 2 cadavers before being used on clinical patients. All biopsy samples were submitted for histopathological examination. RESULTS: Histological diagnosis was obtained in 80% (4/5) of the cases (choroid plexus tumor, astrocytoma, meningioma, and chronic meningoencephalitis of unknown origin). In 1 patient, the results of biopsy were nondiagnostic; postmortem diagnosis was consistent with a low-grade oligodendroglioma. All the patients were discharged within 24 hours after the procedure without complications. This novel stereotactic system allows the surgeon to perform safe, easy-to-use, inexpensive, and minimally invasive precise brain biopsies in dogs and cats, without complications. CLINICAL RELEVANCE: This unique technique could be applied to any size and type of skull and for any type of brain lesions and would provide diagnostic information that would be valuable for future treatment planning and prognosis.

Metastatic extradural melanoma of the lumbar spine in a cat.

A 7-year-old neutered male Domestic shorthair cat, with a 1.5-year history of left eye enucleation secondary to a diffuse iris malignant melanoma, was evaluated for progressive onset of pelvic limb paresis and ataxia with severe thoracolumbar hyperaesthesia and dysorexia. Neurological examination localised a lesion to the T3-L3 spinal cord segments. Magnetic resonance imaging of the thoracolumbar spine showed a well-defined extradural T1-weighted hyperintense non-contrast-enhancing mass, initially suggesting a potential haemorrhagic component. Exploratory surgery revealed a brownish extradural lumbar mass. Histologic examination concluded to a melanoma, most probably metastatic given the animal's previous medical history. This report highlights the importance of collecting a complete medical history, which can help in obtaining a preliminary differential diagnosis in cats with clinical signs of myelopathy. Although the location of this metastasis is particularly unusual both in human and veterinary medicine, making optimal treatment challenging for neurosurgeon, our increased understanding of immune and tumour cell biology during the past decade is likely to improve the future treatments of feline melanoma and its metastases.

Suppurative spinal meningomyelitis in a dog with intra-neutrophilic cerebrospinal fluid cells Ehrlichia canis morulae.

A 2-year-old castrated male Creole Shepherd mixed dog was presented for non-ambulatory paraparesis of the pelvic limbs. The magnetic resonance imaging and cerebrospinal fluid (CSF) analysis were consistent with meningomyelitis. Positive serology for Ehrlichia canis/Ehrlichia ewingii suggested exposure to a pathogen; qPCR on the serum and the CSF confirmed active infection. Ehrlichial morulae were observed within CSF and peripheral blood polymorphonuclear neutrophils; a species-specific PCR confirmed E. canis infection. This is an interesting report of E. canis infection in a dog with morulae observed in neutrophils both in the peripheral blood and CSF.

Video telescope operating monitor-assisted surgery is equivalent to conventional surgery in treatment of cervical intervertebral disc herniation in dogs.

OBJECTIVE: To compare the use of the video telescope operating monitor (VITOM) and use of a conventional unassisted surgical method for treatment of cervical intervertebral disc herniation in dogs. ANIMALS: 39 dogs with cervical intervertebral disc disease. METHODS: Prospective study. Dogs were prospectively nonrandomly assigned to either the VITOM (n = 19) or conventional surgery (20) group depending on VITOM system availability. Signalment and preoperative neurologic status were recorded for all dogs. Preoperative and postoperative CT myelography was performed to compare intervertebral space location, spinal cord dimensions at the decompression level, ventral slot dimensions, and residual disc material. Surgical complications and postoperative neurologic outcomes were recorded. Data were compared between the 2 groups using fixed-effects or mixed-effects models to consider double reading of CT myelography images. RESULTS: No significant differences were noted between the 2 groups regarding the decompression ratio (P = .85), vertebral length body ratio (P = .13), ventral slot width ratio (P = .39), residual disc material (P = .30), and sinus bleeding (P = .12). No significant differences were found between the 2 groups regarding postoperative neurologic grade (P = .17). CLINICAL RELEVANCE: VITOM-assisted ventral slot decompression is equivalent to conventional surgery in treatment of cervical intervertebral disc herniation in dogs. The use of VITOM remains a good alternative to the conventional surgical method.

Spinal epidural and synovial lipomatosis in a 3-year-old Eurasian dog receiving sustained steroid therapy.

This report describes a spinal cord epidural and synovial lipomatosis in a 3-year-old neutered male Eurasian dog. This dog presented for ambulatory paraparesis and was previously treated with immunosuppressive dosages of prednisolone for 2 years. Computed tomography (CT) myelography and magnetic resonnance imaging (MRI) images identified dorsal compression of the thoraco-lumbar spinal cord by hypertrophic epidural fat. Histological examination identified extensive well-differentiated mature adipose tissue in the subepithelial area of the tarsal synovium. Prednisolone is a reported predisposing factor in humans with lipomatosis.

Anatomic study of the canine stifle using low-field magnetic resonance imaging (MRI) and MRI arthrography.

OBJECTIVE: To investigate the use of low-field magnetic resonance imaging (MRI) and MR arthrography in normal canine stifles and to compare MRI images to gross dissection. STUDY DESIGN: Descriptive study. SAMPLE POPULATION: Adult canine pelvic limbs (n=17). METHODS: Stifle joints from 12 dogs were examined by orthopedic and radiographic examination, synovial fluid analysis, and MRI performed using a 0.2 T system. Limbs 1 to 7 were used to develop the MR and MR arthrography imaging protocol. Limbs 8-17 were studied with the developed MR and MR arthrography protocol and by gross dissection. Three sequences were obtained: T1-weighted spin echo (SE) in sagittal, dorsal, and transverse plane; T2-weighted SE in sagittal plane and T1-gradient echo in sagittal plane. RESULTS: Specific bony and soft tissue structures were easily identifiable with the exception of articular cartilage. The cranial and caudal cruciate ligaments were identified. Medial and lateral menisci were seen as wedge-shaped hypointense areas. MR arthrography permitted further delineation of specific structures. MR images corresponded with gross dissection morphology. CONCLUSIONS: With the exception of poor delineation of articular cartilage, a low-field MRI and MR arthrography protocol provides images of adequate quality to assess the normal canine stifle joint.

Autoimmune myasthenia gravis in a ferret.

CASE DESCRIPTION: A 7-month-old neutered male ferret was evaluated for episodic pelvic limb weakness of 2 weeks' duration. CLINICAL FINDINGS: Neurologic examination revealed flaccid tetraparesis with decreased spinal reflexes suggestive of a neuromuscular disease. Results of hematologic and CSF analyses, thoracic radiography, and abdominal ultrasonography were unremarkable. Electrodiagnostic testing revealed subtle spontaneous activity localized to pelvic limb interosseous muscles, unremarkable motor nerve conduction velocities, and lower than typical compound muscle action potential (CMAP) amplitude for tibial nerve stimulation only. A severe decremental response of the CMAP was detected with repetitive nerve stimulation (45.5% at the third ulnar nerve). An esophagogram revealed mild megaesophagus. Intravenous neostigmine methylsulfate administration resulted in immediate resolution of muscle weakness. Cross-reacting anti-acetylcholine receptor (AChR) antibodies were detected in serum (0.35 nmol/L) by use of a canine- and feline-specific muscle extract. Clinical signs and ancillary test results were diagnostic of acquired myasthenia gravis. TREATMENT AND OUTCOME: Pyridostigmine bromide was administered (1 mg/kg [0.45 mg/lb], PO, q 8 h), resulting in complete remission of clinical signs. However, 1 month after the diagnosis, the ferret was euthanized because of recurrence of weakness despite anticholinesterase treatment. CLINICAL RELEVANCE: To the authors' knowledge, this is the first report of acquired myasthenia gravis in a ferret and the first identification of anti-AChR antibodies in this species. Autoimmune myasthenia gravis should be considered in ferrets when weakness and flaccid paresis suggest a neuromuscular disease. Electrodiagnostic testing, anticholinesterase challenge, and AChR antibody titer determination were helpful for diagnosis of this condition.

Demyelinating polyneuropathy with focally folded myelin sheaths in a family of Miniature Schnauzer dogs.

A spontaneous demyelinating polyneuropathy in two young Miniature Schnauzer dogs was characterized clinically, electrophysiologically and histopathologically. Both dogs were related and a third dog, belonging to the same family, had similar clinical signs. On presentation, clinical signs were restricted to respiratory dysfunction. Electrophysiological tests showed a dramatic decrease in both motor and sensory nerve conduction velocities. Microscopic examination of peripheral nerve biopsies (light and electron microscopy, teased nerve fibers), showed that this neuropathy was characterized by segmental demyelination and focally folded myelin sheaths. Various clinical syndromes associated with tomacula or focal thickening of the myelin sheath of the peripheral nerves have been described in humans and shown to be caused by gene mutations affecting the myelin proteins, such as the hereditary neuropathy with liability to pressure palsies or the demyelinating forms of Charcot-Marie-Tooth disease. In animals, a tomaculous neuropathy has been reported in cattle and chickens but not in carnivores. Here we report a demyelinating peripheral neuropathy with tomacula in two Miniature Schnauzer dogs.

High resolution protein electrophoresis of 100 paired canine cerebrospinal fluid and serum.

This study was performed to investigate the diagnostic relevance of cerebrospinal fluid (CSF) high resolution electrophoresis. The laboratory technique was applied to 100 paired samples of canine CSF and serum, with paired samples tested during the same analytical run, as recommended in human medicine. Ninety four of the dogs had a neurological disease and 6 healthy dogs served as a control group. A strong linear correlation between CSF total protein concentration and the albumin quota (AQ) was found in the control group and in the inflammatory (infectious or noninfectious), neoplastic, and miscellaneous groups: AQ = 0.015 CSF total protein--0.102, r = 0.990. This correlation suggests that an increased CSF total protein concentration can be an indicator of blood brain barrier dysfunction. The highest median AQ value was found in the aseptic suppurative meningitis group, but no statistical differences were found between this and the other groups. The AQ, calculated with this technique, did not provide any additional information. Moreover, although unexpected, the electrophoretic profiles were not characteristic of any particular disease. In conclusion, this study did not confirm high resolution electrophoresis of paired CSF and serum samples to be a valuable ancillary diagnostic tool for canine neurological diseases.

Aseptic suppurative meningitis in juvenile boxer dogs: retrospective study of 12 cases.

Immune-mediated central nervous system inflammation is described in a series of 12 juvenile boxer dogs. A diagnosis of steroid-responsive meningitis-arteritis was made based on the clinical presentation and on diagnostic findings. The boxer breed was at a higher risk for this inflammatory condition than other breeds. Long-term follow-up (>2 years) confirmed a better prognosis in this breed than in the beagle and the Bernese mountain dog. Complete resolution of clinical signs without significant deficits or recurrences was obtained in all cases. Early clinical recognition and immunosuppressive treatment resulted in a better response and complete resolution of the disorder.

Presence of neural progenitors in spontaneous canine gliomas: A histopathological and immunohistochemical study of 20 cases.

Gliomas are the most common primary brain tumours in humans and are associated with a poor prognosis. An accurate animal model of human glioma tumorigenesis is needed to test new treatment strategies. Dogs represent a promising model because they develop spontaneous diffusely-infiltrating gliomas. This study investigated whether spontaneous canine gliomas contain cancer stem cells previously identified in all grades of human gliomas. Twenty spontaneous cases of canine gliomas were graded according to the human WHO classification. The expression of different markers of lineage differentiation was evaluated with immunohistochemistry as follows: nestin and CD133 for neural stem cells, doublecortin for neuronal progenitor cells, Olig2 for glial progenitor cells, glial fibrillary acidic protein, vimentin and S-100 for mature glial cells, and NeuN and ßIII-tubulin for mature neurons. Gliomas were characterised as follows: five grade II (oligodendrogliomas); nine grade III (seven anaplastic oligodendrogliomas, one anaplastic astrocytoma, one anaplastic oligoastrocytoma); six grade IV (glioblastomas). Immunohistochemical evaluation revealed that (1) nestin and CD133 were expressed in all grades of gliomas with a higher proportion of positive cells in high-grade gliomas; (2) the expression of S-100 protein and Olig2 did not differ substantially between astrocytic and oligodendroglial tumours, and (3) all gliomas were negative for mature neuron markers. The results demonstrated the presence of undifferentiated neural progenitors in all grades of spontaneous canine gliomas, confirming the relevance of this animal model for further studies on cancer stem cells.

Prevalence of deafness and association with coat variations in client-owned ferrets.

OBJECTIVE: To evaluate the prevalence of congenital sensorineural deafness (CSD) and its association with phenotypic markers in client-owned ferrets. DESIGN: Epidemiological study. ANIMALS: 152 healthy European pet ferrets. PROCEDURES: Brainstem auditory evoked response tests were recorded in ferrets during general anesthesia. Phenotypic markers such as sex, coat color and pattern, coat length (Angora or not), and premature graying trait were assessed. RESULTS: Overall, 44 of the 152 (29%) ferrets were affected by CSD; 10 (7%) were unilaterally deaf, and 34 (22%) were bilaterally deaf. There was no association between CSD and sex or Angora trait, but a strong association between CSD and white patterned coat or premature graying was identified. All panda, American panda, and blaze ferrets were deaf. CONCLUSIONS AND CLINICAL RELEVANCE: The ferrets in this study had a high prevalence of CSD that was strictly associated with coat color patterns, specifically white markings and premature graying. This seemed to be an emerging congenital defect in pet ferrets because white-marked coats are a popular new coat color. Breeders should have a greater awareness and understanding of this defect to reduce its prevalence for the overall benefit of the species.

Bromide-associated lower airway disease: a retrospective study of seven cats.

Seven cats were presented for mild-to-moderate cough and/or dyspnoea after starting bromide (Br) therapy for neurological diseases. The thoracic auscultation was abnormal in three cats showing increased respiratory sounds and wheezes. Haematology revealed mild eosinophilia in one cat. The thoracic radiographs showed bronchial patterns with peribronchial cuffing in most of them. Bronchoalveolar lavage performed in two cats revealed neutrophilic and eosinophilic inflammation. Histopathology conducted in one cat showed endogenous lipid pneumonia (EnLP). All cats improved with steroid therapy after Br discontinuation. Five cats were completely weaned off steroids, with no recurrence of clinical signs. In one cat, the treatment was discontinued despite persistent clinical signs. The cat presenting with EnLP developed secondary pneumothorax and did not recover. Br-associated lower airway disease can appear in cats after months of treatment and clinical improvement occurs only after discontinuing Br therapy.

A retrospective study of 40 dogs with polyarthritis.

OBJECTIVE: To characterize the epidemiologic, clinical, laboratory, and radiographic findings from dogs with polyarthritis (PA). STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Forty dogs. METHODS: Medical records of 40 dogs with a diagnosis of PA were reviewed. Retrieved data included breed, age at admission, sex, weight, clinical signs, and the results of synovial fluid analysis, complete blood count, serum chemistry profile, urinalysis, serologic screening tests for infectious diseases, and radiographic examination of affected joints. RESULTS: The incidence of PA was 0.37%. Twenty-nine breeds were represented; 16 dogs were male, and 24 were female. Mean body weight was 20.1 +/- 15 kg. The mean age at admission was 5.6 +/- 4 years. Eighty percent of dogs with PA had difficulty or reluctance walking, 35% were lame, 33% had spontaneous vocalization without any obvious reason, 20% had exercise intolerance, 18% were febrile, and 7.5% had an inability to rise or move. Joint pain was identified in 40% of dogs. Synovial fluid color varied from colorless (36%) to yellow-tinged (36%) or hemorrhagic (28%). Synovial fluid mean cell count varied from 10 cells (400x) to 50 cells (1,000x). Leukocytosis occurred in 59% of the dogs and was more frequently identified in dogs with very severe synovial inflammation. Thirty-one percent of affected dogs were anemic. Serum biochemical profiles were considered abnormal in 13% of the dogs. Joint radiography did not identify erosive arthritis. CONCLUSIONS: PA is a common cause of locomotor abnormalities in dogs; however, true lameness and articular pain are not common clinical findings in dogs with PA. CLINICAL RELEVANCE: PA should be considered in the differential diagnosis for all dogs with difficulty walking.