Multiple myeloma and primary erythrocytosis in a dog.

A 13-year-old spayed female mixed breed dog was referred for impaired ambulation, limb tremors, back pain, hypergammaglobulinemia on cellulose acetate electrophoresis, and mild proteinuria. Conventional radiology and magnetic resonance imaging (MRI) suggested multifocal neoplastic bone lesions. At the referral examination, lameness and bright red mucous membranes were observed. Severe erythrocytosis, a monoclonal peak in the ß-2 globulin detected by capillary zone electrophoresis, severe proteinuria, bone marrow infiltration of plasma cells, and low serum erythropoietin concentrations were reported. The final diagnosis was multiple myeloma associated with severe primary erythrocytosis. This presentation in a dog is interesting because the combination of both disorders is rare in humans and has not been reported in dogs. Key clinical message: Although rare, multiple myeloma and primary erythrocytosis can occur together in dogs.

Myélome multiple et érythrocytose primaire chez un chien. Une chienne de race mixte stérilisée âgée de 13 ans a été référée pour troubles de la marche, tremblements des membres, maux de dos, hypergammaglobulinémie à l'électrophorèse sur acétate de cellulose et protéinurie légère. La radiologie conventionnelle et l'imagerie par résonance magnétique (IRM) suggéraient des lésions osseuses néoplasiques multifocales. Lors de l'examen de référence, une boiterie et des muqueuses rouge vif ont été observées. Une érythrocytose sévère, un pic monoclonal de la globuline ß-2 détecté par électrophorèse capillaire, une protéinurie sévère, une infiltration de la moëlle osseuse par des plasmocytes et de faibles concentrations sériques d'érythropoïétine ont été rapportés. Le diagnostic final était un myélome multiple associé à une érythrocytose primaire sévère. Cette présentation chez un chien est intéressante car l'association des deux conditions est rare chez l'homme et n'a pas été rapportée chez le chien.Message clinique clé :Bien que rares, le myélome multiple et l'érythrocytose primaire peuvent survenir simultanément chez le chien.(Traduit par Dr Serge Messier).

Intra-Articular Administration of Autologous Micro-Fragmented Adipose Tissue in Dogs with Spontaneous Osteoarthritis: Safety, Feasibility, and Clinical Outcomes.

Similar to the disease affecting humans, osteoarthritis (OA) is a painful musculoskeletal condition affecting 20% of the adult canine population. Several solutions have been proposed, but the results achieved to date are far from being satisfactory. New approaches, such as intra-articular delivery of cells (including mesenchymal stromal cells), have been proposed. Among the many sources, the adipose tissue is considered very promising. We evaluated the safety, feasibility, and efficacy of a single intra-articular injection of autologous and micro-fragmented adipose tissue (MFAT) in 130 dogs with spontaneous OA. MFAT was obtained using a minimally invasive technique in a closed system and injected in the intra- and/or peri-articular space. Clinical outcomes were determined using orthopedic examination and owners' scores for up to 6 months. In 78% of the dogs, improvement in the orthopedic score was registered 1 month after treatment and continued gradually up to 6 months when 88% of the dogs improved, 11% did not change, and 1% worsened compared with baseline. Considering the owners' scores at 6 months, 92% of the dogs significantly improved, 6% improved only slightly, and 2% worsened compared with baseline. No local or systemic major adverse effects were recorded. The results of this study suggest that MFAT injection in dogs with OA is safe, feasible, and beneficial. The procedure is time sparing and cost-effective. Post injection cytological investigation, together with the clinical evidence, suggests a long-term pain control role of this treatment. The spontaneous OA dog model has a key role in developing successful treatments for translational medicine. Stem Cells Translational Medicine 2018;7:819-828.

Adult autologous mesenchymal stem cells for the treatment of suspected non-infectious inflammatory diseases of the canine central nervous system: safety, feasibility and preliminary clinical findings.

BACKGROUND: Non-infectious inflammatory diseases of the canine central nervous system (CNS) are common idiopathic disorders grouped under the term meningoencephalomyelitis of unknown origin (MUO). Ante mortem diagnosis is achieved via assessment of clinical signs, magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) analysis, but the definitive diagnosis needs histopathological examination. MUO are mostly considered as autoimmune CNS disorders, so that suppressing the immune reaction is the best management method for patients. Mesenchymal stem cells (MSCs) are under investigation to treat autoimmune and degenerative disorders due to their immunomodulatory and regenerative properties. This study aims to verify the safety, feasibility, and efficacy of MSCs treatment in canine idiopathic autoimmune inflammatory disorders of the CNS. METHODS: Eight dogs presented with acute onset and rapid progression of multifocal neurological signs were selected to the study. In all patients' physical and neurological examinations, MRI and CSF analyses were performed. Clinical diagnosis in all cases was MUO. All selected dogs responded initially to immunosuppressive drugs (prednisone and a combination of prednisolone and cytosine arabinoside) but developed undesirable side effects. For all eight dogs, the owners considered euthanasia but accepted cell therapy as a last possibility. Autologous bone marrow MSCs (BMMSCs), isolated, cultured, and expanded, were administered by intrathecal (IT) injection in the cisterna magna intravenously (IV) and by intra-arterial (IA) injection in the right carotid artery. Adverse effects and clinical response were monitored for 6 months up to 2-year follow-up. RESULTS: The use of autologous BMMSCs in dogs with MUO was safe for IT, IV, and IA injections. No major short- or long-term adverse effects were registered. All the dogs presented early improvement in their general and neurological conditions, with particular effect on cervical pain. The group of dogs treated by IT+IA administration showed a shorter time of reaction to therapy compared to the group treated by IT+IV administration. CONCLUSIONS: MSCs treatment in dogs affected by MOU is safe and feasible. A larger group of dogs is needed to confirm these results as well as CNS histology in order to better understand the underlying mechanisms.

Magnetic resonance imaging features of sinonasal disorders in horses.

Diseases of paranasal sinuses and nasal passages in horses can be a diagnostic challenge because of the complex anatomy of the head and limitations of many diagnostic modalities. Our hypothesis was that magnetic resonance (MR) imaging would provide excellent anatomical detail and soft tissue resolution, and would be accurate in the diagnosis of diseases of the paranasal sinuses and nasal passages in horses. Fourteen horses were imaged. Inclusion criteria were lesions located to the sinuses or nasal passages that underwent MR imaging and subsequent surgical intervention and/or histopathologic examination. A low field, 0.3 tesla open magnet was used. Sequences in the standard protocol were fast spin echo T2 sagittal and transverse, spin echo T1 transverse, short-tau inversion recovery (STIR) dorsal, gradient echo 3D T1 MPR dorsal (plain and contrast enhanced), spin echo T1 fatsat (contrast enhanced). Mean scan time to complete the examination was 53 min (range 39-99 min). Lesions identified were primary or secondary sinusitis (six horses), paranasal sinus cyst (four horses), progressive ethmoid hematoma (two horses), and neoplasia (two horses). The most useful sequences were fast spin echo T2 transverse and sagittal, STIR dorsal and FE3D MPR (survey and contrast enhanced). Fluid accumulation, mucosal thickening, presence of encapsulated contents, bone deformation, and thickening were common findings observed in MR imaging. In selected horses, magnetic resonance imaging is a useful tool in diagnosing lesions of the paranasal sinuses and nasal passages.

Effects of observer on the diagnostic accuracy of low-field MRI for detecting canine meniscal tears.

Low-field MRI (lfMRI) has become increasingly accepted as a method for diagnosing canine meniscal tears in clinical practice. However, observer effects on diagnostic accuracy have not been previously reported. In this study, 50 consecutive stifle joints with clinical and radiologic evidence of cranial cruciate ligament insufficiency were investigated by lfMRI and arthroscopy. Fifteen observers who had varying levels of experience and who were unaware of arthroscopic findings independently reviewed lfMRI studies and recorded whether lateral and medial meniscal tears were present. Diagnostic accuracy (sensitivity, specificity, positive (PPV) and negative predictive value (NPV)) was determined for each observer and median values were calculated for all observers, using arthroscopy as the reference standard. Interrater agreement was determined based on intraclass correlation coefficient (ICC) analysis. Observer level of experience was compared with diagnostic sensitivity and specificity using correlation analysis. Based on pooled data for all observers, median sensitivity, specificity, PPV, and NPV for lfMRI diagnosis of lateral meniscal tears were 0.00, 0.94, 0.05, and 0.94, respectively. Median sensitivity, specificity, PPV, and NPV for medial meniscal tears were 0.74, 0.89, 0.83, and 0.79, respectively. Interrater agreement for all menisci was fair (0.51). Menisci were less consistently scored as having no tears (ICC = 0.13) than those scored as having tears (ICC = 0.50). No significant correlations between observer experience and diagnostic sensitivity/specificity were identified. Findings indicated that the accuracy of lfMRI for diagnosing canine meniscal tears was poor to fair and observer-dependent. Future studies are needed to develop standardized and widely accepted lfMRI criteria for diagnosing meniscal tears.

Microcystic meningioma of the fourth ventricle in a dog.

A 5-year-old female cross-breed dog was presented with a 1-month history of progressive changes in the posture of the head and in the gait. At neurological examination the dog showed a central vestibular syndrome lateralized to the left. MRI showed a space occupying lesion within the fourth ventricle, characterized by iso- to hypointensity in T1 and hyperintensity in T2 with a heterogeneous contrast uptake. Histologically, a neoplasia composed of meningothelial cells forming compact whorls with slight atypia, and stellate cells delimitating microcysts containing eosinophilic fluid was observed. Neoplastic cells were positive for vimentin and negative for GFAP and FVIII. A diagnosis of intraventricular microcystic meningioma was achieved. Intraventricular meningiomas in dogs are rarely encountered and reports of meningiomas within the fourth ventricle have not yet been described. Although choroid plexus tumor is the most frequent neoplasia localized in the fourth ventricle, intraventricular meningioma should be included in the differential diagnoses.

Fibromatosis in a young Bernese Mountain Dog: clinical, imaging, and histopathological findings.

A young, intact, male Bernese Mountain Dog was presented to the animal hospital for lameness and diffuse thickening of the soft tissue in the right hind limb. Magnetic resonance imaging revealed multiple, multilobular, space-occupying lesions within and between the muscles of the right femur. Biopsies taken from the lesions revealed an infiltrative mass composed mainly of collagen fibers and a low density of benign-appearing fibroblasts. These findings were compatible with a diagnosis of a fibromatosis. Taking the age of onset into account, infantile fibromatosis was most likely. A deep fibromatosis, similar to that seen in adults, could not be excluded based on histology.

Laser-Doppler measurements of spinal cord blood flow changes during hemilaminectomy in chondrodystrophic dogs with disk extrusion.

OBJECTIVES: (1) To assess spinal cord blood flow (SCBF) during surgical treatment of disk extrusion in dogs and (2) to investigate associations between SCBF, clinical signs, presurgical MRI images, and 24-hour surgical outcome. STUDY DESIGN: Cohort study. ANIMALS: Chondrodystrophic dogs with thoracolumbar disk extrusion (n=12). METHODS: Diagnosis was based on clinical signs and MRI findings, and confirmed at surgery. Regional SCBF was measured intraoperatively by laser-Doppler flowmetry before, immediately after surgical spinal cord decompression, and after 15 minutes of lavaging the lesion. Care was taken to ensure a standardized surgical procedure to minimize factors that could influence measurement readings. RESULTS: A significant increase in intraoperative SCBF was found in all dogs (Wilcoxon's signed-rank test; P=.05) immediately after spinal cord decompression and after 15 minutes. Changes in SCBF were not associated with duration of clinical signs; initial or 24-hour neurologic status; or degree of spinal cord compression assessed by MRI. CONCLUSION: SCBF increases immediately after spinal cord decompression in dogs with disk herniation; however, increased SCBF was not associated with a diminished 24-hour neurologic status. CLINICAL RELEVANCE: An increase in SCBF does not appear to be either associated with the degree of spinal cord compression or of a magnitude sufficient to outweigh the benefit of surgical decompression by resulting in clinically relevant changes in 24-hour outcome.

Modified temporal approach for a rostro-temporal basal meningioma in a cat.

An 11-year-old neutered female domestic shorthair indoor cat was presented to our hospital for treatment of a left-sided rostro-temporal basal meningioma. Focal seizures in the facial muscles had been observed sporadically for 1 year. Two weeks prior to presentation the cat had developed generalised seizures and was treated with symptomatic anticonvulsive treatment. Focal facial seizures, especially on the right side, persisted after medical therapy. From the computed tomography scan, a basal meningioma was suspected by the treating veterinarian. A left-sided suprazygomatical temporobasal approach to the zygomatic arch was chosen because it causes less soft tissue damage. After craniotomy, durotomy and gentle dorsal retraction of the left piriform lobe, the meningioma was removed. Postoperative magnetic resonance imaging confirmed complete excision of the tumour. One day after surgery the cat was alert and a left-sided facial nerve palsy was noticed. Otherwise the neurological examination was normal. Anticonvulsive and eye moistening therapy was continued for 3 months. Six months after surgery the cat was clinically normal without any recurrence of seizures.

Influence of intervertebral disc fenestration at the herniation site in association with hemilaminectomy on recurrence in chondrodystrophic dogs with thoracolumbar disc disease: a prospective MRI study.

OBJECTIVE: To describe the influence of fenestration at the disc herniation site on recurrence in thoracolumbar disc disease of chondrodystrophoid dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: Chondrodystrophic dogs (n=19). METHODS: Dogs were divided into 2 groups: group 1 (9 dogs) had thoracolumbar disc extrusion (Hansen type I) treated by hemilaminectomy and concomitant fenestration of the affected intervertebral disc and group 2 (10 dogs) had hemilaminectomy without fenestration. All dogs had 3 magnetic resonance imaging (MRI) examinations: preoperatively, immediately postoperatively to assess removal of herniated disc material, and again 6 weeks after surgery. RESULTS: There were 13 male and 6 female dogs; mean age, 7.1 years. Thoracolumbar disc herniation was confirmed with MRI. Immediate post surgical MRI revealed that the herniated disc removal was complete in all but 1 dog and that fenestration did not lead to complete removal of nucleus pulposus within the intervertebral disc space. On the 3rd MRI examination, none of the group 1 dogs had further disc material herniation at the fenestrated site. Six of the 10 group 2 dogs had a recurrence of herniation leading to clinical signs in 3 dogs (pain in 2 dogs, paresis in 1 dog). CONCLUSION: In thoracolumbar disc herniation, fenestration of the affected intervertebral disc space prevents further extrusion of disc material. CLINICAL RELEVANCE: Fenestration reduces the risk of early recurrence of disc herniation and associated postoperative complications.

Ventral intraspinal cysts associated with the intervertebral disc: magnetic resonance imaging observations in seven dogs.

OBJECTIVE: To report clinical and diagnostic imaging features, and outcome after surgical treatment of ventral intraspinal cysts in dogs. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=7) with ventral intraspinal cysts. METHODS: Clinical signs, magnetic resonance imaging (MRI) findings and surgical findings of 7 dogs and histologic findings (1 dog) with intraspinal cysts associated with the intervertebral disc were reviewed. RESULTS: Ventral intraspinal cyst is characterized by: (1) clinical signs indistinguishable from those of typical disc herniation; (2) an extradural, round to oval, mass lesion with low T1 and high T2 signal intensity on MRI, compatible with a liquid-containing cyst; (3) cyst is in close proximity to the intervertebral disc; and (4) MRI signs of disc degeneration. Although the exact cause is unknown, underlying minor disc injury may predispose to cyst formation. CONCLUSION: Intraspinal cysts have clinical signs identical to those of disc herniation. Given the close proximity of the cyst to the corresponding disc and the similarity of MRI findings to discal cysts in humans, we propose the term "canine discal cyst" to describe this observation. CLINICAL RELEVANCE: Discal cysts should be considered in the differential choices for cystic extradural compressing lesions.

Magnetic resonance imaging features of orbital inflammation with intracranial extension in four dogs.

This retrospective study describes the clinical and magnetic resonance (MR) imaging features of chronic orbital inflammation with intracranial extension in four dogs (two Dachshunds, one Labrador, one Swiss Mountain). Intracranial extension was observed through the optic canal (n=1), the orbital fissure (n=4), and the alar canal (n=1). On T1-weighted images structures within the affected skull foramina could not be clearly differentiated, but were all collectively isointense to hypointense compared with the contralateral, unaffected side, or compared with gray matter. On T2-, short tau inversion recovery (STIR)-, or fluid-attenuated inversion recovery (FLAIR)-weighted images structures within the affected skull foramina appeared hyperintense compared with gray matter, and extended with increased signal into the rostral cranial fossa (n=1) and middle cranial fossa (n=4). Contrast enhancement at the level of the affected skul foramina as well as at the skull base in continuity with the orbital fissure was observed in all patients. Brain edema or definite meningeal enhancement could not be observed, but a close anatomic relationship of the abnormal tissue to the cavernous sinus was seen in two patients. Diagnosis was confirmed in three dogs (one cytology, two biopsy, one necropsy) and was presumptive in one based on clinical improvement after treatment. This study is limited by its small sample size, but provides evidence for a potential risk of intracranial extension of chronic orbital inflammation. This condition can be identified best by abnormal signal increase at the orbital fissure on transverse T2-weighted images, on dorsal STIR images, or on postcontrast transverse or dorsal images.

MRI characteristics and histology of bone marrow lesions in dogs with experimentally induced osteoarthritis.

Signal changes within the bone marrow adjacent to osteoarthritic joints are commonly seen on magnetic resonance (MR) images in humans and in dogs. The histological nature of these lesions is poorly known. In this study, we describe the MR imaging of bone marrow lesions adjacent to the stifle joints of dogs with experimental osteoarthritis over 13 months. Histology of the proximal tibia at the end of the study was compared with the last MR imaging findings. In five adult dogs, the left cranial cruciate ligament was transected. Post-operatively, MR imaging was performed at 1, 2, 3, 4, 6, 8, and 13 months. Dogs were euthanised after 13 months and histological specimen of the proximal tibia were evaluated. Bone marrow edema like MR imaging signal changes were seen in every MR examination of all dogs in one or more locations of the proximal tibia and the distal femur. Lesions varied in size and location throughout the whole study with the exception of constantly seen lesions in the epiphyseal and metaphyseal region at the level of the tibial eminence. On histology, hematopoiesis and myxomatous transformation of the bone marrow and/or intertrabecular fibrosis without signs of bone marrow edema were consistent findings in the areas corresponding to the MR imaging signal changes. We conclude that within the bone marrow, zones of increased signal intensity on fat suppressed MR images do not necessarily represent edema but can be due to cellular infiltration. Contrary to humans, hematopoiesis is seen in bone marrow edema-like lesions in this canine model of osteoarthritis.

Multiple meningiomas: clinical, radiological, surgical, and pathological findings with outcome in four cats.

The present report describes the clinical signs, magnetic resonance imaging (MRI) findings, surgical procedure, pathological findings and follow-up in four cats with multiple meningiomas; three castrated male and one spayed female domestic shorthair indoor cats, ranging in age from 11 to 14 years. In three of four cats, clinical signs at presentation were suggestive of a focal lesion. Three cats had two meningiomas and one had four meningiomas. Most of the tumours were supratentorial, one arose from the tentorium and one was infratentorial. The duration of presenting signs before surgery ranged from 10 days to 11 months. Postoperative MRI revealed complete gross tumour removal in three cases. In one cat with two cranial fossa meningiomas, subtotal excision with a small basal remnant (2 x 2 mm) of the ventral part of one meningioma lying on the floor of the skull, was observed. Based on histopathological architecture, six tumours revealed features of a transitional subtype meningioma, and four of a meningotheliomatous meningioma. In each cat, the multiple meningiomas were all assigned to the same histopathological group. The preoperative presenting signs had resolved by the follow-up examinations 4 weeks after surgery in two cats. Long-term follow-up evaluation revealed that surgically-induced or exacerbated neurological deficits in two cats had completely or almost completely resolved within 8 weeks of surgery. All patients are still alive 12 to 21 months after surgery and no clinical signs of recurrence could be detected at that time.

Low-field Mri and arthroscopy of meniscal lesions in ten dogs with experimentally induced cranial cruciate ligament insufficiency.

Little is known about the magnetic resonance imaging (MRI) appearance of canine meniscal lesions. The aim of this study is to describe the MR appearance of meniscal lesions in dogs with experimentally induced cranial cruciate ligament (CCL) deficiency. The pilot study revealed dogs weighing approximately 10 kg to be too small for meniscal evaluation on low-field MRI. In the main study, dogs weighing approximately 35 kg were used. The left CCL was transected and low-field MRI was performed regularly until 13 months post-surgery. Normal menisci were defined as grade 0. Intrameniscal lesions not reaching any surface corresponded to grade 1 if focal and to grade 2 if linear or diffuse. Grade 3 lesions consisted in linear tears penetrating a meniscal surface. Grade 4 lesions included complex signal changes or meniscal distortion. Between 2 and 13 months post-surgery, all dogs developed grade 4 lesions in the medial meniscus. Most of them corresponded to longitudinal or bucket handle tears on arthroscopy and necropsy. Two dogs showed grade 3 lesions reaching the tibial surface of the lateral meniscus on MRI but not in arthroscopy. Such tears are difficult to evaluate arthroscopically; MRI provides more accurate information about the tibial meniscal surface. Grades 1 and 2 lesions could not be differentiated from presumably normal menisci with our imaging technique. An MRI grading system better adapted to canine lesions has yet to be developed. MRI is a helpful tool for the diagnosis of complete tears in the canine meniscus, especially in larger dogs.

Imaging of the canine and feline temporomandibular joint: a review.

The radiographic anatomy of the temporomandibular joint in the dog and cat is described in dorsoventral and oblique projections. The positioning for different oblique views in conventional radiography and technical details of computed tomography are reviewed. Typical radiographic features of craniomandibular osteopathy, dysplasia, luxation, subluxation, fractures, ankylosis, degenerative joint disease, infection, and neoplasia involving the temporomandibular joint are discussed.