Refractory otitis media and otitis externa in a koala (Phascolarctos cinereus) treated with total ear canal ablation and lateral bulla osteotomy.

BACKGROUND: To the authors' knowledge, this is the first report fully describing the surgical and medical management of otitis media and otitis externa in the koala (Phascolarctos cinereus) treated by total ear canal ablation and lateral bulla osteotomy. CASE REPORT: An adult male koala captured as part of a monitoring project in South East Queensland was diagnosed with chlamydial cystitis. Purulent discharge from the right ear was also observed; diagnostic imaging was consistent with otitis media and otitis externa. Yokenella regensburgei was repeatedly cultured from the site. Clinical signs resolved with topical antibiotic therapy; however, recrudesced following cessation of antibiotics. A total ear canal ablation and lateral bulla osteotomy was performed, followed by an extended period of systemic antibiotic therapy. Mild facial nerve paresis was observed for 4 weeks postoperatively and resolved spontaneously. The koala remained clinically healthy for the 6 months it was monitored following release. CONCLUSION: Total ear canal ablation combined with lateral bulla osteotomy appears to be an appropriate surgical intervention for otitis media combined with otitis externa refractory to medical management in the koala. Transient postoperative facial nerve paresis is a possible complication, as documented in other species. To the authors' knowledge this is the first case of Yokenella regensburgei infection outside of humans and American alligators (Alligator mississippiensis); the clinical significance of this pathogen in the koala remains unknown.

Brachial artery thrombosis in a dog causing monoparesis mimicking nerve sheath tumor.

There are few differential diagnoses for non-orthopedic thoracic limb lameness in adult dogs aside from nerve tumors and disk-associated nerve compression; this report introduces another etiology. A 9-year-old male castrated mixed dog presented with an episodic history of nonweight-bearing thoracic limb lameness. Additional clinical signs included an atrophied thoracic limb with cool paw pads and painful axillary region. Magnetic resonance imaging, computed tomography, ultrasound, and exploratory surgery confirmed a chronic thrombus of the right brachial artery. No underlying cause for the thrombus was identified. The dog has been successfully managed on long-term rivaroxaban and clopidogrel. Follow-up ultrasound of the thrombus suggested early remodeling.

Horner Syndrome With Ipsilateral Wing Paresis in a Wild, Juvenile Yellow-Tailed Black Cockatoo (Calyptorhynchus funereus).

A juvenile yellow-tailed black cockatoo (Calyptorhynchus funereus) was presented with paresis of the right wing, ptosis, and miosis of the right eye; feather erection of the right side of the head and neck; and a penetrating injury over the right pectoral muscle. Temporary reversal of ptosis, miosis, and feather erection after administration of phenylephrine drops confirmed a diagnosis of Horner syndrome. Computed tomographic imaging revealed a fractured rib, traumatic lung lesions, and subcutaneous emphysema. The right-sided Horner syndrome and wing paresis were attributed to a sympathetic nerve trauma of the eye and feathers and to the brachial plexus, respectively. This report describes the diagnosis and resolution of ptosis and miosis within 8 weeks and recovery of feather symmetry and wing function within 11 weeks of the cockatoo's initial presentation with a conservative-management treatment plan.

Intramedullary spinal nephroblastoma in a mixed breed dog.

A 1-year-old male mixed breed dog presented for the evaluation of progressive hindlimb paresis. Neurological examination indicated a spinal cord lesion between the 3rd thoracic and 3rd lumbar vertebrae. Magnetic resonance imaging (MRI) revealed an intramedullary spinal cord lesion located at the level of the 1st and 2nd lumbar vertebrae. Following cytoreductive surgery of the mass, palliative radiation therapy was administered. A diagnosis of nephroblastoma was made based on histological examination. After radiation therapy, the disappearance of the spinal lesion was confirmed by MRI. The dog was improved from gait abnormality and alive at 16 months postoperatively, with slight signs of neurological dysfunction.

[Ventral stabilization of an atlantoaxial subluxation with screws and polymethylmetacrylat in a miniature Yorkshire Terrier]. / Ventrale Stabilisation einer atlantoaxialen Subluxation mittels Schrauben und Polymethylmetacrylat bei einem Miniatur-Yorkshire-Terrier.

A 6-month-old female Miniature Yorkshire Terrier with a bodyweight of 1.1 kg was presented due to non-ambulatory tetraparesis. Latero-lateral radiographs showed an increased space between the spinal process of the axis and the dorsal arch of the atlas, with craniodorsal displacement and rotation of the body of the axis in relation to the atlas. Computed tomography also revealed a craniodorsal displacement of the axis in relation to the atlas with an unfusioned dens. Initially, a dorsal surgical approach was chosen and an intermuscular suture pattern was used attempting to achieve reduction of the subluxation. Radiographically and clinically the result however was not acceptable. In a second surgery, a ventral stabilization technique (using 4 1.5 mm screws in atlas and axis with polymethylmetacrylate) was performed. The achieved repositioning was considered acceptable. The dog was provided with a cervical bandage for 6 weeks. Clinically, the patient improved progressively and remains free of clinical signs up to the time of manuscript preparation, 37 months post-operatively.

Canine adrenocorticotropic hormone-producing sinusoidal neuroendocrine tumor associated with Cushing's disease.

An 18-year-old male Yorkshire Terrier was admitted with a history of neurological signs including dullness and progressive tetraparesis. Physical examination revealed bilaterally symmetrical alopecia and pot-bellied abdomen. Computed tomography and necropsy examination showed a mass across the frontal sinus and cerebral frontal lobe, bilateral adrenocortical hyperplasia, and hepatomegaly. Histopathologically, the tumor lesions consisted of sheets, nests, or cords of small- to medium-sized round-to-polyhedral cells. Adrenal cortex showed bilateral diffuse cellular proliferation, and some hepatocytes showed intracytoplasmic glycogen accumulation. Immunohistochemically, the tumor cells were positive for pancytokeratin, chromogranin-A, neuron-specific enolase, S100, synaptophysin, and thyroid transcription factor-1 but negative for microtubule-associated proein-2 and neurofilament, leading to the diagnosis of neuroendocrine tumor. These tumor cells were also positive for adrenocorticotropic hormone.

Cerebral cysts of ependymal or ventricular origin in a juvenile rhesus macaque (Macaca mulatta) with neurologic signs.

Naturally occurring neurologic disease in non-human primates may be attributable to a wide-range of causes, including infectious agents, congenital or acquired malformations, degenerative diseases, and, rarely, neoplasia. We report a case of ataxia and paresis in a juvenile rhesus macaque with ependymal-lined cerebral cysts.

[Possibilities of diagnostics in unilateral fibular-nerve-paresis in a calf]. / Möglichkeiten der Diagnostik bei einseitiger N.-fibularis-Parese beim Kalb.

INTRODUCTION: The present case report describes the workup of unilateral fibular-nerve-paresis in a female neonatal Fleckvieh calf. The calf was admitted to the Clinic for Ruminants with Ambulatory and Herd Health Services, Ludwig- Maximilians-University Munich as part of an investigation into a herd problem. The herd problem was presented as movement disorder in neonatal calves with an incidence of 10%. A physical, hematological, and musculoskeletal, as well as neurological examination was performed, and a diagnosis of a left-sided paresis of the fibular-nerve (N. fibularis) was made. Further special examinations including sonography, magnetic resonance tomography and muscle, lymph node, and nerve biopsies of the affected limb of the calf were also carried out. Advanced imaging examinations suggested the presence of inflammatory changes caudal to the left stifle joint in the region of the fibular nerve. Histopathological examination of the nerve biopsy confirmed the presence of a fibular-nerve-neuritis. Inflammatory changes in the ischiocrural-muscles were most likely injection-induced, consistent with the history of the veterinary practitioner and the examination results.

Nematode eggs observed in cytology of cerebrospinal fluid diagnostic for intramedullary Spirocerca lupi spinal cord migration.

Spinal spirocercosis due to aberrant Spirocerca lupi nematode migration is an emerging etiology for acute myelitis in dogs in Israel, causing severe, mostly nonsymmetrical hind limb paresis or paralysis, and sometimes tetraparesis or tetraparalysis. So far, incidental identification of parasites during spinal surgery or at necropsy provides the only definite diagnosis, while antemortem diagnosis of this condition has been uncertain. Specifically, antemortem diagnosis is based on the typical clinical presentation of acute, progressive, asymmetrical hind limb paresis or paralysis, with moderate to severe eosinophilic to mixed cerebrospinal fluid (CSF) pleocytosis and increased CSF protein concentration. Exclusion of other differential diagnoses also requires using spinal cord imaging. In this novel report, we document a case of an intradural spinal spirocercosis in a dog, diagnosed antemortem, by detecting S lupi eggs in the CSF, and subsequent treatment, resulting in the resolution of the clinical signs.

A clinical case of neosporosis in a 4-week-old holstein friesian calf which developed hindlimb paresis postnatally.

A 4-week-old female Holstein Friesian calf presented with hindlimb paresis. Neurologic examination of spinal reflexes revealed depressed or absent reflexes of the hindlimbs. Menace responses on both sides disappeared on examination of cranial nerves. The calf was finally diagnosed with Neospora caninum infection by pathological findings including nonsuppurative inflammation associated with cysts in the cerebrum and spinal cord. High levels of antibody against recombinant surface antigen 1 of N. caninum (NcSAG1) were detected by ELISA from both serum and cerebrospinal fluid (CSF) samples. This result suggests that detection of antibodies against N. caninum by NcSAG1-ELISA in serum and CSF could be useful for the clinical diagnosis of neosporosis in calves with acquired neurological signs.

Acute basophilic leukaemia in a three-month-old calf.

A three-month-old female Holstein-Friesian calf was presented with acute tetraparesis. After neurological examination a multifocal lesion in the central nervous system was suspected with the most pronounced lesions between the third thoracic and the third lumbar vertebrae. Haematological examination revealed moderate anaemia as well as severe thrombocytopenia, neutropenia and leucocytosis. A blood smear and bone marrow aspirate exhibited predominantly blasts with basophilic granulation leading to a diagnosis of acute (myeloid) leukaemia with involvement of the basophilic lineage or an acute basophilic leukaemia. Magnetic resonance imaging revealed spinal cord compression; at necropsy, extensive localised haemorrhages extending into the thoracic vertebral canal were found. Histopathology revealed a large population of blast cells in several tissues including the meninges. Due to multifocal detection of neoplastic cells in the vascular system, neoplasia of the haematopoietic system was assumed in agreement with haematological findings. Signs of paresis could be explained by intramedullary spinal cord haemorrhage and myeloid infiltrations of meningeal vessels. In conclusion, despite its rarity, acute myeloid leukaemia with involvement of the basophilic lineage may be considered in diagnosing calves with progressive deteriorating general condition, paresis, leucocytosis with moderate basophilic differentiation or haemorrhagic disorders.

Acquired cervical spinal arachnoid diverticulum in a cat.

A one-year-old, female entire, domestic, shorthair cat presented with acute onset non-ambulatory tetraparesis. Magnetic resonance imaging was consistent with a C3-C4 acute non-compressive nucleus pulposus extrusion and the cat was treated conservatively. The cat was able to walk after 10 days and was normal 2 months after presentation. The cat was referred five and a half years later for investigation of an insidious onset 3-month history of ataxia and tetraparesis. Magnetic resonance imaging of the cervical spine was repeated, demonstrating a spinal arachnoid diverticulum at C3 causing marked focal compression of the spinal cord. This was treated surgically with hemilaminectomy and durectomy. The cat improved uneventfully and was discharged 12 days later.

Thoracolumbar intradural disc herniation in eight dogs: clinical, low-field magnetic resonance imaging, and computed tomographic myelography findings.

Intradural disc herniation is a rarely reported cause of neurologic deficits in dogs and few published studies have described comparative imaging characteristics. The purpose of this retrospective cross sectional study was to describe clinical and imaging findings in a group of dogs with confirmed thoracolumbar intradural disc herniation. Included dogs were referred to one of four clinics, had acute mono/paraparesis or paraplegia, had low field magnetic resonance imaging (MRI) and/or computed tomographic myelography, and were diagnosed with thoracolumbar intradural disc herniation during surgery. Eight dogs met inclusion criteria. The prevalence of thoracolumbar intradural disc herniation amongst the total population of dogs that developed a thoracolumbar intervertebral disc herniation and that were treated with a surgical procedure was 0.5%. Five dogs were examined using low-field MRI. Lesions that were suspected to be intervertebral disc herniations were observed; however, there were no specific findings indicating that the nucleus pulposus had penetrated into the subarachnoid space or into the spinal cord parenchyma. Thus, the dogs were misdiagnosed as having a conventional intervertebral disc herniation. An intradural extramedullary disc herniation (three cases) or intramedullary disc herniation (two cases) was confirmed during surgery. By using computed tomographic myelography (CTM) for the remaining three dogs, an intradural extramedullary mass surrounded by an accumulation of contrast medium was observed and confirmed during surgery. Findings from this small sample of eight dogs indicated that CTM may be more sensitive for diagnosing canine thoracolumbar intradural disc herniation than low-field MRI.

Monoparesis in association with feline pulmonary carcinoma: a literature review with 3 new cases.

We describe 3 cases of cats that were presented with a sudden onset of monoparesis as a result of arterial thromboembolism without evidence of cardiovascular disease that were subsequently diagnosed with a primary pulmonary carcinoma. Arterial tumor thromboemboli due to pulmonary carcinoma should be considered as a differential diagnosis in cases of lameness or paresis in older cats. We theorize that large tumor emboli may obstruct peripheral arteries leading to acute monoparesis.

Monoparésie associée au carcinome pulmonaire félin : compte rendu de la littérature avec 3 nouveaux cas. Nous décrivons 3 cas de chats qui ont été présentés avec l'apparition soudaine de monoparésie en raison d'un thrombo-embolisme artériel sans preuve de maladie cardiovasculaire qui ont été subséquemment diagnostiqués avec un carcinome pulmonaire primaire. Les thromboembolies des tumeurs artérielles causées par le carcinome pulmonaire devraient être considérées comme un diagnostic différentiel dans les cas de boiterie ou de parésie chez les chats âgés. Nous présentons la théorie que les embolies de grosses tumeurs peuvent bloquer les artères périphériques causant une monoparésie aiguë.(Traduit par Isabelle Vallières).

Ventral occipito-atlanto-axial fluid-filled lesion causing dynamic spinal cord compression in a cat.

Cystic lesions affecting the vertebral canal or spinal cord have rarely been reported in cats. A 3-year-old female neutered domestic longhair cat presented for evaluation of a 2-year-history of episodes of ataxia and paresis affecting all limbs. Neurological examination was consistent with a lesion in the C1-C5 spinal cord segments. Magnetic resonance imaging (MRI) showed a fluid-filled lesion at the occipito-atlanto-axial region causing dynamic spinal cord compression on flexion of the neck. The imaging characteristics were compatible with a juxta-articular cyst. To our knowledge, this is the first report of a fluid-filled lesion causing dynamic cervical spinal cord compression in a cat and highlights the importance of performing flexion-extension MRI views in diagnosing cases with dynamic spinal cord compression.

Spontaneous high-grade glial intramedullary tumor of the spine in a rhesus macaque (Macaca mulatta).

BACKGROUND: A 4-year-old rhesus macaque presented with acute, progressive paresis of the extremities. METHODS: A complete blood count, serum biochemical analysis, neurologic exam and necropsy were performed. RESULTS: The clinical, histopathological, and immunohistochemical findings confirmed a high-grade intramedullary glial tumor of the spinal cord that was most consistent with an ependymoma. CONCLUSIONS: We describe a case of a naturally occurring spontaneous spinal cord neoplasia in a non-human primate.

Probable lumbar acute non-compressive nucleus pulposus extrusion in a cat with acute onset paraparesis.

A spinal cord lesion localised caudal to the L6 spinal segment was diagnosed in a 2-year-old female spayed domestic longhair cat with acute onset paraparesis. Magnetic resonance imaging findings were consistent with an acute, non-compressive nucleus pulposus extrusion of the L5-L6 intervertebral disc. The cat was successfully managed with supportive care, including cage confinement.

Markers of Borna disease virus infection in cats with staggering disease.

Borna disease virus (BDV) is a RNA-virus causing neurological disorders in a wide range of mammals. In cats, BDV infection may cause staggering disease. Presently, staggering disease is a tentative clinical diagnosis, only confirmed at necropsy. In this study, cats with staggering disease were investigated to study markers of BDV infection aiming for improvement of current diagnostics. Nineteen cats fulfilled the inclusion criteria based on neurological signs and pathological findings. In 17/19 cats, BDV infection markers (BDV-specific antibodies and/or BDV-RNA) were found, and antibodies in serum (13/16, 81%) were the most common marker. BDV-RNA was found in 11/19 cats (58%). In a reference population without neurological signs, 4/25 cats were seropositive (16%). The clinical history and neurological signs in combination with presence of BDV infection markers, where serology and rRT-PCR on blood can be helpful tools, improve the diagnostic accuracy in the living cat.

Neurological lameness in the cat: common causes and clinical approach.

PRACTICAL RELEVANCE: Neurological causes of lameness are infrequently seen in cats but they are an important consideration when an obvious orthopaedic cause cannot be identified. Monoparetic cats are also frequently presented for veterinary investigation with the main complaint being lameness. CLINICAL CHALLENGES: Neurological causes of lameness may be difficult to determine without access to advanced imaging modalities, electrodiagnostics or cerebrospinal fluid analysis. AUDIENCE: This review, aimed at all veterinarians who treat cats, sets out to describe the specific approach to cats with lameness that cannot be attributed to an orthopaedic cause. It describes the diagnosis and management of the most common neurological conditions responsible for lameness or monoparesis in cats.