Case report: Focal heterotopic ossification in paravertebral muscles as a cause of neurogenic lameness in a dog.

This case report describes a 17-month-old Pudelpointer with recurring motor impairment localized to the left thoracic limb. A neurological exam highlighted lameness in that limb, accompanied by pre-scapular swelling. Radiographs and magnetic resonance imaging detected an osseous structure in soft tissues close to the fifth cervical vertebra, and subsequent surgery uncovered adjacent cervical spinal nerve impingement. Histology of the bony structure revealed heterotopic ossification in paravertebral muscles. Mild bone re-formation at the operating site was detected after a 2-year period, but the patient was asymptomatic. This article reports the first case of heterotopic ossification with spinal nerve entrapment in a dog and adds a new differential diagnosis to the causes of neurogenic lameness in dogs.

Cervical intervertebral disc disease in 60 Yorkshire terriers.

Intervertebral disc extrusion (IVDE) is a common neurological condition in many dog breeds. This study aimed to describe this condition in Yorkshire terriers (YT) and calculate the prevalence of this condition amongst the YTs with neurological diseases. This is a double-centre retrospective study which was conducted in two arms. The first part of the study, describing the clinical features and prognosis of cervical (C) IVDE in YTs, is based on data from 2005 to 2021. The second part of the study calculated the prevalence of C IVDE amongst the YTs with neurological diseases based on data from 2016 to 2021. A retrospective search through the medical records was conducted. YTs with C IVDE diagnosed with MRI and confirmed surgically were eligible for inclusion in this study. Sixty YTs were included in the first part of the study. There were 48 (80%) dogs with acute onset and 12 (20%) with chronic onset with acute deterioration. Ambulation was preserved in 31 (51.7%) dogs on admission, and the remaining 29 (48.3%) dogs were non-ambulatory. No significant association was found between ambulation on admission and recovery status (p = 0.547). Seventy-three intervertebral spaces were treated during the surgical intervention. Relapses were seen in seven (11.7%) dogs. Forty-nine (81.7%) dogs were ambulatory at discharge. A complete recovery was observed in 46 (76.7%) dogs; the remaining dogs (14, 23.3%) were classified as incomplete recovery. A significant difference was found in time to ambulation (p = 0.0238) and time to discharge (p = 0.0139) between the on-admission ambulatory and non-ambulatory dogs. Three hundred and eight YTs were diagnosed with neurological diseases between 2016 and 2021 in one referral centre. C IVDE was diagnosed in 31 (10.06%) dogs. This is the first study explicitly describing the C IVDE in YTs and establishing the prevalence of this condition amongst YTs with other neurological disorders.

Corrigendum: Transient Postural Vestibulo-Cerebellar Syndrome in Three Dogs With Presumed Cerebellar Hypoplasia.

[This corrects the article DOI: 10.3389/fvets.2020.00453.].

Transient Postural Vestibulo-Cerebellar Syndrome in Three Dogs With Presumed Cerebellar Hypoplasia.

This case study presents a unique transient postural vestibular syndrome in three dogs. The transient postural symptoms present as pronounced vestibulo-cerebellar signs after altering the position of the head. Magnetic resonance imaging findings of the brain suggest caudal cerebellar hypoplasia, affecting vermis, and floccular lobes bilaterally in case 1, and hypoplasia of the nodulus vermis in cases 2 and 3. No progression of clinical signs was reported in minimum of 4 months period.

IMAGING DIAGNOSIS - MAGNETIC RESONANCE IMAGING OF INTRACRANIAL INFLAMMATORY FIBROSARCOMA IN A MIXED BREED DOG.

An 8-year-old mixed-breed dog presented with progressive behavioral changes and altered mentation. Magnetic resonance imaging (MRI) of the brain revealed an olfactory and frontal lobe extra-axial mass. The mass exhibited the following MRI signal intensity characteristics: T2W mixed, T1W iso- to hypointense, FLAIR hyperintense, and strong contrast enhancement. The mass was removed with cavitronic ultrasonic surgical aspirator (CUSA) assisted neurosurgery. Based on histopathological appearance and immunohistochemistry, the diagnosis of inflammatory fibrosarcoma was made. To our knowledge, this is the first report describing MRI characteristics of intracranial inflammatory fibrosarcoma in the veterinary literature.

Neuroendocrine pituitary macroadenoma of a cat presenting with primary adipsia and hypernatraemia.

CASE SUMMARY: A male neutered Ragdoll cat aged 11 years and 9 months presented with a 6 month history of weight loss and a 1 month history of lethargy and adipsia. A thorough clinical investigation confirmed a diagnosis of primary adipsia and hypernatraemia secondary to a non-secretory neuroendocrine pituitary macroadenoma. RELEVANCE AND NOVEL INFORMATION: Primary adipsia is a very rare clinical entity. This report is the first to describe primary adipsia secondary to a non-secretory pituitary macroadenoma in the cat. The veterinary literature available in this field is very limited and this report adds a new differential diagnosis for cats presenting with primary hypodipsia.

MRI characteristics of fourth ventricle arachnoid diverticula in five dogs.

Intracranial arachnoid diverticula (cysts) are rare accumulations of cerebrospinal fluid (CSF) within the arachnoid membrane. The purpose of this retrospective study was to describe magnetic resonance imaging (MRI) characteristics of fourth ventricle arachnoid diverticula in a group of dogs. The hospital's medical records were searched for dogs with MRI studies of the brain and a diagnosis of fourth ventricle arachnoid diverticulum. Clinical characteristics were recorded from medical records and MRI studies were reinterpreted by a board-certified veterinary radiologist. Five pediatric dogs fulfilled inclusion criteria. Clinical signs included cervical hyperaesthesia, obtundation, tetraparesis, and/or central vestibular syndrome. In all five dogs, MRI findings were consistent with obstructive hydrocephalus, based on dilation of all ventricles and compression of the cerebellum and brainstem. All five dogs also had cervical syringohydromyelia, with T2-weighted hyperintensity of the gray matter of the cord adjacent to the syringohydromyelia. A signal void, interpreted as flow disturbance, was observed at the mesencephalic aqueduct in all dogs. Four dogs underwent surgical treatment with occipitalectomy and durotomy. A cystic lesion emerging from the fourth ventricle was detected in all four dogs during surgery and histopathology confirmed the diagnosis of arachnoid diverticula. Three dogs made excellent recovery but deteriorated shortly after surgery and were euthanized. Repeat MRI in two dogs revealed improved hydrocephalus but worsening of the syringohydromyelia. Findings from the current study supported theories that fourth ventricle arachnoid diverticula are secondary to partial obstruction of the central canal or lateral apertures and that arachnoid diverticula are developmental lesions in dogs.

Feline ischemic myelopathy and encephalopathy secondary to hyaline arteriopathy in five cats.

Five cats presented with acute-onset neurological signs. Magnetic resonance imaging in four cats showed a T2-weighted hyperintense spinal cord lesion that was mildly contrast-enhancing in three cats. Owing to inflammatory cerebrospinal fluid changes three cats were treated with immunosuppression. One cat was treated with antibiotics. All cats improved initially, but were eventually euthanased owing to the recurrence of neurological signs. Histopathology in all cats showed hyaline degeneration of the ventral spinal artery, basilar artery or associated branches with aneurysmal dilation, thrombosis and ischemic degeneration and necrosis of the spinal cord and brain. Two cats also had similar vascular changes in meningeal vessels. Vascular hyaline degeneration resulting in vascular aneurysmal dilation and thrombosis should be a differential diagnosis in cats presenting with acute central nervous system signs.

Effect of extradurally administered morphine on postoperative analgesia in dogs undergoing surgery for thoracolumbar intervertebral disk extrusion.

OBJECTIVE: To investigate the effect of intraoperative extradural morphine administration on postoperative analgesia in dogs undergoing thoracolumbar spinal surgery to treat disk extrusion. DESIGN: Prospective clinical trial. ANIMALS: 26 client-owned dogs undergoing thoracolumbar spinal surgery. PROCEDURES: Animals were randomly allocated to receive morphine (0.1 mg/kg [0.045 mg/lb], extradurally) or no treatment (control group). Following preanesthetic medication with methadone (0.25 mg/kg [0.11 mg/lb], IM), anesthesia was induced with propofol and maintained with isoflurane or sevoflurane in oxygen. Lidocaine and fentanyl were administered during surgery in both groups at fixed rates. In the morphine administration group, morphine was splashed over the dura mater immediately prior to wound closure. Postoperative analgesia was assessed for 48 hours by assessors unaware of group allocation, and methadone was administered as rescue analgesic. Demographic characteristics, urinary output, days of hospitalization, and perioperative use of analgesics were compared via a Mann-Whitney U test. RESULTS: Demographic data were similar between groups. In the morphine administration group, 2 of 13 dogs required postoperative methadone, and in the control group, methadone was administered to 11 of 13 dogs. The total number of doses of methadone administered in the 48 hours after surgery was 28 in the control group and 3 in the morphine administration group. No adverse effects were recorded in any group. CONCLUSIONS AND CLINICAL RELEVANCE: Intraoperative extradural morphine administration was effective in reducing postoperative analgesic requirement. Dogs undergoing thoracolumbar spinal surgery benefited from topical administration of preservative-free morphine administered directly on the dura mater as part of analgesic management.

MRI features of CNS lymphoma in dogs and cats.

The magnetic resonance (MR) imaging features of central nervous system lymphoma in eight dogs and four cats are described. Intracranial lesions affected the rostrotentorial structures in six dogs and caudotentorial structures in two cats. Lesions affected the spinal cord in two dogs and in two cats. One dog and one cat with intracranial lymphoma had signs of local extracranial extension and lymphadenopathy. Lesions were considered extraparenchymal in four dogs and three cats, intraparenchymal in two dogs and one cat, and appeared to have both intra- and extraparenchymal components in two dogs. All lesions were hyperintense in T2-weighted images when compared to white matter, most were hypointense in T1-weighted images (7/12), and most were hyperintense in fluid-attenuated inversion recovery (FLAIR) images (5/9). When compared to grey matter, these lesions appear either isointense (5/12) or hyperintense (7/12) on T2-weighted images, half of them were hypointense in T1-weighted images (6/12), and most were isointense in FLAIR images (7/9). Lesion margins were usually indistinct in T2-weighted images (10/12) and had perilesional hyperintensity in FLAIR images (7/9). The majority of lesions (10/12) had abnormal meninges around the lesion and half (6/12) had generalized contrast enhancement. Mass effect was evident in all lesions. Although not specific, when combined with the history and neurologic signs, MR features aid presumptive diagnosis that should be confirmed by cytology or histopathology.

Acute spinal cord injury in the cat: causes, treatment and prognosis.

PRACTICAL RELEVANCE: Acute spinal conditions are a common emergency presentation in general veterinary practice and have the potential to cause devastating spinal cord injury (SCI) and consequent severe neurological deficits. SCI can be divided into two subgroups: exogenous SCI (vertebral fracture and/or luxation/subluxation) and endogenous SCI (intervertebral disc extrusion and ischaemic myelopathy). CLINICAL CHALLENGES: The majority of cats with SCI have concurrent injuries. The clinician must perform a thorough physical examination and prioritise and then stabilise the life-threatening problems before focusing on the neurological examination. The possibility of multiple sites of SCI and spinal shock can make interpretation of the neurological examination challenging. While plain radiographs or myelography are usually diagnostic, they do not give direct information about the integrity of the spinal cord parenchyma or the severity of any damage. If facilities or experienced staff capable of performing the necessary surgery are not available, or advanced imaging is indicated, referral to a specialist veterinary institution should be considered. AUDIENCE: This review is aimed at clinicians dealing with feline SCI in the emergency setting or at first-opinion level, and discusses causes, initial management, specific treatment and prognosis. PATIENT GROUP: While any cat may potentially be affected by SCI, there is a tendency for exogenous SCI to be more common in younger individuals and, in the authors' experience, pure-breed cats are very rarely presented. Endogenous SCI can be seen in any breed and is typically a condition of adult cats.

Thiamine deficiency in a cat: resolution of MRI abnormalities following thiamine supplementation.

Thiamine (vitamin B(1)) is an essential component of a number of metabolic pathways and thiamine deficiency results in a progressive encephalopathy in both humans and animals. Confirming thiamine deficiency is problematic and relies on demonstrating reduced red blood cells transketolase activity, or indirect methods including urinary organic acid analysis and dietary analysis. The characteristic and selective vulnerability of different brain regions in carnivores has been demonstrated by magnetic resonance (MR) imaging in the dog and cat as an aid to diagnosis. A 2-year-old, female, domestic shorthair cat was presented with an acute onset of seizures and ataxia. MR imaging was consistent with thiamine deficiency and supplementation resulted in a progressive clinical improvement. Repeated MR imaging 4 days after starting thiamine supplementation revealed near complete resolution of the MR abnormalities. Repeated MR imaging following appropriate therapy may be useful to further confirm thiamine deficiency.