Relationship between magnetic resonance imaging findings and histological grade in spinal peripheral nerve sheath tumors in dogs.

BACKGROUND: Peripheral nerve sheath tumors (PNSTs) are a group of neoplasms originating from Schwann cells or pluripotent cell of the neural crest. Therapeutic options and prognosis are influenced by their degree of malignancy and location. HYPOTHESIS/OBJECTIVES: Identify magnetic resonance imaging (MRI) features predictive of PNST histologic grade. ANIMALS: Forty-four dogs with histopathological diagnosis of spinal PNSTs and previous MRI investigation. METHODS: A multicenter retrospective study including cases with (a) histopathologic diagnosis of PNST and (b) MRI studies available for review. Histologic slides were reviewed and graded by a board-certified pathologist according to a modified French system (FNCLCC) for grading soft tissue sarcomas. The MRI studies were reviewed by 2 board-certified radiologists blinded to the grade of the tumor and the final decision on the imaging characteristics was reached by consensus. Relationships between tumor grade and histological and MRI findings were assessed using statistical analysis. RESULTS: Forty-four cases met inclusion criteria; 16 patients were PNSTs Grade 1 (low-grade), 19 were PNSTs Grade 2 (medium-grade), and 9 were PNSTs Grade 3 (high-grade). Large volume (P = .03) and severe peripheral contrast enhancement (P = .04) were significantly associated with high tumor grade. Degree of muscle atrophy, heterogeneous signal and tumor growth into the vertebral canal were not associated with grade. CONCLUSIONS AND CLINICAL IMPORTANCE: Grade of malignancy was difficult to identify based on diagnostic imaging alone. However, some MRI features were predictive of high-grade PNSTs including tumor size and peripheral contrast enhancement.

Multicenter Study of Clinical Presentation, Treatment, and Outcome in 41 Dogs With Spinal Epidural Empyema.

There is limited information on canine spinal epidural empyema (SEE). The aim of this multicenter retrospective study is to describe the clinical presentation and outcome of dogs undergoing spinal surgery or conservative management for SEE. Forty-one dogs met the inclusion criteria; the SEE was treated surgically in 17 dogs and conservatively in 24 dogs. Two dogs underwent spinal surgery after failure of conservative management, meaning that 19 dogs in total had spinal surgery. Long-term (i.e., >6 months) follow-up was available in 35 dogs (19 conservatively treated and 16 surgically treated dogs). Recovery to a functional pet status was achieved in 15/19 (78.9%) conservatively treated and 12/16 (75%) surgically treated dogs. There was no significant difference (p = 1.000) in long-term outcome between conservatively and surgically treated dogs (78.9 and 75%, respectively). However, significantly more surgically treated dogs were non-ambulatory at presentation (9/17 vs. 5/24, p = 0.048) compared with conservatively treated dogs. This study suggests that conservative treatment may be appropriate for dogs with SEE that are ambulatory at presentation and that surgically treated dogs generally have good outcomes. Age may be a negative prognostic indicator as dogs with poor long-term outcomes were significantly older than dogs with a good long-term outcome (p = 0.048). A larger prospective randomized study may provide further insight on treatment and outcome of SEE in dogs.

Transthoracic Vertebral Distraction and Stabilization in 10 Dogs with Congenital Thoracic Vertebral Malformations.

OBJECTIVE: The aim of this study was to describe the surgical technique and outcomes of dogs with congenital thoracic vertebral body malformations (CTVBM) treated with unilateral vertebral distraction and stabilization with monocortical screws and polymethylmethacrylate (PMMA). STUDY DESIGN: Medical records of 10 client-owned dogs with CTVBM were retrospectively searched for signalment, history, neurological examination, neurological grade based on the modified Frankel scale (MFS), diagnostic method, CTVBM location, Cobb's angle, and vertebral canal angle (VCA), surgical procedure, complications and long-term follow-up. RESULTS: One dog suffered cardiac arrest 24 hours post-surgery and died. Median follow-up in nine dogs was 26.5 months (12-50 months). Cobb's angle improved from 33-83 to 10-46 degrees and the VCA ratio from 97-138 to 122-164 degrees. The MFS improved from 3 (n = 3)-4 (n = 7) to 4 (n = 2)-6 (n = 7). Seven dogs recovered full function. Nine dogs improved after surgery compared with preoperative status, recovering ambulation when lost or achieving normal neurological examination in seven cases. No complications were reported during the follow-up period (12-50 months). CONCLUSION: Unilateral transthoracic vertebral distraction and stabilization with monocortical screws and PMMA for treatment of compressive myelopathy due to CTVBM achieved long-term neurological improvement in 9 of 10 dogs.

Paraneoplastic ganglioradiculoneuritis in a cat with a plasma cell tumour.

CASE SUMMARY: An 8-year-old neutered female domestic longhair cat was presented for investigation of a 48 h history of lethargy and pelvic limb ataxia. MRI of the spinal cord and vertebral column (C1 to sacrum) and brain was unremarkable. Lumbar cerebrospinal fluid analysis revealed pleocytosis and increased protein concentration. Thoracic radiographs and abdominal ultrasound were unremarkable. Anti-inflammatory doses of prednisolone were administered. Clinical deterioration occurred over the following 2 days, with the development of lower motor neuron deficits in both thoracic limbs. On repetition of the MRI, bilateral enlargement, T2-weighted hyperintensity, and marked contrast enhancement of the C7, C8 and T1 nerve roots, spinal nerves and brachial plexuses were observed. Infectious disease testing was negative. An immune-mediated inflammatory process was suspected and immunosuppressive doses of prednisolone were commenced. The clinical signs improved transiently, but marked deterioration occurred after 2 weeks. The patient was euthanased and a post-mortem examination was performed. A lymphocytic inflammatory infiltrate was detected in the C7, C8 and T1 nerve roots and dorsal root ganglia, and neoplastic plasma cells were identified in multiple organs. A diagnosis of non-cutaneous extramedullary plasmacytoma with multiorgan involvement and paraneoplastic ganglioradiculoneuritis was reached. RELEVANCE AND NOVEL INFORMATION: Paraneoplastic ganglioradiculoneuritis in association with a plasma cell neoplasia has not been previously reported in the cat and should be considered as a differential diagnosis for cats with clinical or imaging evidence of an inflammatory process affecting the nerve roots, spinal nerves or brachial plexuses.

Prevalence and clinical characteristics of phenobarbitone-associated adverse effects in epileptic cats.

OBJECTIVES: The study objective was to investigate the prevalence and clinical characteristics of phenobarbitone-associated adverse effects in epileptic cats. METHODS: The medical records of two veterinary referral clinics from 2007 to 2017 were searched for cats fulfilling the inclusion criteria of a diagnosis of epilepsy, treatment with phenobarbitone and available follow-up information on the occurrence of adverse effects. Follow-up information was obtained from the medical records of the primary veterinarian and referral institutions and a questionnaire completed by the cats' owners. RESULTS: Seventy-seven cats met the inclusion criteria. Fifty-eight were affected by idiopathic epilepsy and 19 by structural epilepsy. One or more of the following adverse effects were reported in 47% of the cats: sedation (89%); ataxia (53%); polyphagia (22%); polydipsia (6%); polyuria (6%); and anorexia (6%). Logistic regression analyses revealed significant associations between adverse effect occurrence and both phenobarbitone starting dosage and administration of a second antiepileptic drug (AED). For each 1 mg/kg q12h increment of phenobarbitone, the likelihood of adverse effects increased 3.1 times. When a second AED was used, the likelihood of adverse effects increased 3.2 times. No association was identified between epilepsy aetiology and adverse effect occurrence. An idiosyncratic adverse effect, characterised by severe neutropenia and granulocytic hypoplasia, was diagnosed in one cat. This resolved following phenobarbitone discontinuation. CONCLUSIONS AND RELEVANCE: The prevalence of phenobarbitone-associated adverse effects was 47%. Sedation and ataxia were most common. These are type A adverse effects and are predictable from phenobarbitone's known pharmacological properties. In the majority of cases, adverse effects occurred within the first month of treatment and were transient. Idiosyncratic (type B) adverse effects, which were not anticipated given the known properties of the drug, occurred in one cat. Increased phenobarbitone starting dosage and the addition of a second AED were significantly associated with the occurrence of adverse effects.

Noise-Induced Hearing Loss in 3 Working Dogs.

Three working dogs were diagnosed with noise-induced hearing loss following exposure to loud noise. Physical and neurologic examinations in each case revealed no significant findings. Brainstem auditory evoked response (BAER) demonstrated bilateral sensorineural deafness. One dog did not regain hearing but continued working with adjusted protocols utilizing hand signals. One dog was lost to follow-up. The last dog was treated with oral Vitamin B complex (daily), Vitamin E (400 IU daily), and N-acetyl-cystine (600 mg daily) and regained hearing 2 months later, based on repeat BAER testing.

Neurological abnormalities in 97 dogs with detectable pituitary masses.

Background: Pituitary tumours are common neoplasms of the sellar region in small animals. However, detailed information regarding the spectrum and severity of possible neurological signs are lacking. Objective: To retrospectively describe the neurological abnormalities in a population of dogs with a detectable pituitary mass (DPM) and relate them with the size of the mass and magnetic resonance imaging (MRI) signs of brain compression (BC). Client-owned dogs were included in the study if they had MRI showing a DPM and a detailed neurological examination. The neurological signs were evaluated in relation to the pituitary height/brain ratio (P:B ratio) and the presence/absence of brain compression. Results: Ninety-seven dogs were enrolled. Besides abnormal mentation and behaviour (77%), gait (61%) and cranial nerve abnormalities (44%), other unreported neurological signs observed included postural abnormalities (21%), pain and/or hyperesthesia (25%) and abnormal postural and proprioceptive reactions (49%). The majority of dogs with DPM had signs of BC. The presence of a high pituitary height/brain area and BC represented a risk factor for developing mental status abnormalities. Conclusion: Neurological signs recorded in DPM-affected dogs include not only the typical forebrain signs but also gait disturbances and hyperesthesia. Neurological signs are positively associated with increased P:B ratio and MRI signs of brain compression.

Neurological signs and MRI findings in 12 dogs with multiple myeloma.

Vertebral lesions and associated neurological signs occur in dogs with multiple myeloma, however, veterinary literature describing MRI findings is currently lacking. The objective of this multicenter, retrospective, case series study was to describe neurological signs and MRI findings in a group of dogs that presented for spinal pain or other neurological deficits and had multiple myeloma. Electronic records of four veterinary referral hospitals were reviewed. Dogs were included if they had a pathologically confirmed diagnosis of multiple myeloma, had presented for spinal pain or other neurological signs, and had undergone MRI of the vertebral column. The MRI studies were evaluated and the anatomical location of lesion(s), signal intensity, presence of extra-dural material, degree of spinal cord compression, extent of vertebral lesions, and contrast enhancement were recorded. Twelve dogs met inclusion criteria. Most dogs (n = 8) had a chronic progressive history, with varying degrees of proprioceptive ataxia and paresis (n = 11), and spinal pain was a feature in all dogs. The MRI findings were variable but more consistent features included the presence of multiple expansile vertebral lesions without extension beyond the outer cortical limits of affected vertebrae, and associated extradural material causing spinal cord compression. The majority of lesions were hyper- to isointense on T2 (n = 12) and T1-weighted (n = 8) sequences, with variable but homogeneous contrast-enhancement (n = 12). These described MRI characteristics of multiple myeloma may be used to aid early identification and guide subsequent confirmatory diagnostic steps, to ultimately improve therapeutic approach and long-term outcome.

MRI in 30 cats with traumatic brain injury.

OBJECTIVES: The aim of this study was to evaluate the MRI findings in cats following traumatic brain injury (TBI), and establish which features identified might correlate with prognosis. METHODS: The magnetic resonance images of 30 cats with clinical signs attributed to the brain following TBI were retrospectively reviewed to assess the imaging features seen and their correlation with outcome. RESULTS: Twenty-one of 30 cats had a good outcome (full recovery or minor ongoing neurological deficits); the other nine either died or had ongoing neurological deficits that significantly affected quality of life. There was evidence of parenchymal injury in only 20/30 cats, including 8/9 that had a poor outcome. The frequency of bilateral or multifocal parenchymal lesions on T2-weighted imaging, and mass effect, particularly caudal transtentorial herniation, was statistically significantly higher in patients with a poorer outcome. Extra-axial haemorrhage was not identified. Concurrent soft tissue injury was noted in all cats, with a poorer prognosis statistically associated with a peripharyngeal pattern of injury and orbital trauma. CONCLUSIONS AND RELEVANCE: The number of cases with MRI-identified brain pathology, the patterns of injuries identified and the specific imaging features that appear to have effects on prognosis differ in this series of cats from those published in similar case series of dogs. Further work is needed to establish if cat-specific guidelines are needed to assess brain MRI following trauma.

Hereditary ataxia in four related Norwegian Buhunds.

CASE DESCRIPTION Two 12-week-old Norwegian Buhunds from a litter of 5 were evaluated because of slowly progressive cerebellar ataxia and fine head tremors. Two other females from the same pedigree had been previously evaluated for similar signs. CLINICAL FINDINGS Findings of general physical examination, CBC, and serum biochemical analysis were unremarkable for all affected puppies. Brain MRI and CSF analysis, including PCR assays for detection of Toxoplasma gondii, Neospora caninum, and canine distemper virus, were performed for 3 dogs, yielding unremarkable results. Urinary organic acid screening, enzyme analysis of fibroblasts cultured from skin biopsy specimens, and brainstem auditory-evoked response testing were performed for 2 puppies, and results were also unremarkable. TREATMENT AND OUTCOME The affected puppies were euthanized at the breeder's request, and their brains and spinal cords were submitted for histologic examination. Histopathologic findings included a markedly reduced expression of calbindin D28K and inositol triphosphate receptor 1 by Purkinje cells, with only mild signs of neuronal degeneration. Results of pedigree analysis suggested an autosomal recessive mode of inheritance. Candidate-gene analysis via mRNA sequencing for 2 of the affected puppies revealed no genetic variants that could be causally associated with the observed abnormalities. CLINICAL RELEVANCE Findings for the dogs of this report suggested the existence of a hereditary form of ataxia in Norwegian Buhunds with histologic characteristics suggestive of Purkinje cell dysfunction. The presence of hereditary ataxia in this breed must be considered both in clinical settings and for breeding strategies.

Late-onset recurrence of neurological deficits after surgery for spinal arachnoid diverticula.

Spinal cord dysfunction secondary to spinal arachnoid diverticula (SAD) has been widely reported in the veterinary literature and there is some suggestion that surgical treatment may provide better outcomes than medical treatment. Despite this, previous reports have mentioned cases with recurrence of clinical signs following surgical treatment but the cause for this has not been further investigated. The medical records of seven dogs and one cat which presented for investigation of recurrence of neurological deficits at least six months after surgery for SAD were retrospectively reviewed. Median time to relapse of the neurological deficits was 20.5 months after surgery. On repeated imaging, 3/8 cases showed clear regrowth of diverticulum, 2/8 cases showed dorsal compression at the previous laminectomy site (presumed to be the laminectomy membrane), and 3/8 cases showed herniation of the spinal cord through the laminectomy defect associated with a stellate appearance to the spinal cord with small multiloculated areas of dilation of the subarachnoid space. Repeat surgical intervention was most successful in the cases where SAD recurrence was identified while medical treatment resulted in either subtle improvement or stabilisation on the clinical signs, sometimes followed by slow deterioration.

Outcome comparison in dogs with a presumptive diagnosis of thoracolumbar fibrocartilaginous embolic myelopathy and acute non-compressive nucleus pulposus extrusion.

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.

Investigating the potential of the anti-epileptic drug imepitoin as a treatment for co-morbid anxiety in dogs with idiopathic epilepsy.

BACKGROUND: Behavioural changes associated with idiopathic epilepsy (IE) have been identified in dogs, with fear and anxiety-related problems seen in both drug-naïve dogs and dogs treated with anti-epileptic drugs (AEDs). Treating anxiety-related behaviour in dogs with IE may be challenging, as seizures are a contraindication for many conventional anxiolytic drugs. In addition, many dogs with IE are already treated with AEDs to reduce their seizure frequency, which may have negative effects if used in polytherapy. Imepitoin is low-affinity partial agonist at the benzodiazepine (BDZ) site of the GABAA receptor, and has been demonstrated to have both anticonvulsant and anxiolytic effects in laboratory rodents. Imepitoin has been developed for the treatment of IE in dogs, with demonstrated anticonvulsant effects and high tolerability and safety. To date, imepitoin's potential to reduce anxiety in dogs with IE has not been investigated. An online survey was conducted to investigate the effect of imepitoin on fear and anxiety-related behaviours in dogs with IE. Eighty-five valid responses were received from owners of dogs with IE currently treated with imepitoin. Anxiety-related behaviour was quantified before and during imepitoin treatment using a validated questionnaire tool (C-BARQ). RESULTS: No differences were observed in the five fear/anxiety-related measures between the two time periods (before vs. during treatment) for dog directed fear, stranger directed fear, non-social fear, pain sensitivity and separation related behaviour. A median 45% reduction in seizure frequency/month was observed following imepitoin treatment; however, imepitoin did not appear effective in reducing seizure frequency in a minority of cases. Polyphagia was the most common chronic side effect, and more side effects were reported in polytherapy cases. CONCLUSIONS: Imepitoin does not appear to improve anxiety-related behaviour in dogs with IE treated with this medication for its anti-epileptic effects. Investigating the effects of imepitoin upon the behaviour of dogs with recognised behavioural anxiety-related problems (e.g. specific fears and phobias, separation related behaviours), in both healthy dogs and dogs with epilepsy is required to further explore any potential anxiolytic effects of this medication.

Neurogenic urinary retention in cats following severe cluster seizures.

Case series summary Four cats that presented with severe cluster seizures developed neurogenic urinary retention in the postictal phase. None of the cats had previous seizures. Micturition was reported as normal in all cats for 3 or more years before seizure onset. All cats required a continuous rate infusion of propofol to control the seizure activity. In all cats manual bladder expression was performed every 8 h until recovery of normal micturition. One cat was started on phenoxybenzamine to reduce internal urethral sphincter tone. All cats recovered normal micturition within 4 weeks of the last cluster of seizures. Relevance and novel information Transient neurogenic urinary retention has not previously been reported in cats or dogs following severe cluster seizures. Urinary retention should be considered a potential postictal deficit, requiring prompt recognition and treatment to avoid urinary tract infection and detrusor muscle atony.

An Inversion Disrupting FAM134B Is Associated with Sensory Neuropathy in the Border Collie Dog Breed.

Sensory neuropathy in the Border Collie is a severe neurological disorder caused by the degeneration of sensory and, to a lesser extent, motor nerve cells with clinical signs starting between 2 and 7 months of age. Using a genome-wide association study approach with three cases and 170 breed matched controls, a suggestive locus for sensory neuropathy was identified that was followed up using a genome sequencing approach. An inversion disrupting the candidate gene FAM134B was identified. Genotyping of additional cases and controls and RNAseq analysis provided strong evidence that the inversion is causal. Evidence of cryptic splicing resulting in novel exon transcription for FAM134B was identified by RNAseq experiments. This investigation demonstrates the identification of a novel sensory neuropathy associated mutation, by mapping using a minimal set of cases and subsequent genome sequencing. Through mutation screening, it should be possible to reduce the frequency of or completely eliminate this debilitating condition from the Border Collie breed population.

Distal polyneuropathy in an adult Birman cat with toxoplasmosis.

CASE SUMMARY: A 6-year-old female spayed Birman cat presented with a history of weight loss, stiff and short-strided gait in the pelvic limbs and reluctance to jump, progressing to non-ambulatory tetraparesis over 6 weeks. Poor body condition, dehydration and generalised muscle wastage were evident on general examination. Neurological examination revealed mildly depressed mental status, non-ambulatory flaccid tetraparesis and severely decreased proprioception and spinal reflexes in all four limbs. The neuroanatomical localisation was to the peripheral nervous system. Haematology, feline immunodeficiency virus/feline leukaemia virus serology, serum biochemistry, including creatine kinase and thyroxine, thoracic radiographs and abdominal ultrasound did not reveal significant abnormalities. Electromyography revealed fibrillation potentials and positive sharp waves in axial and appendicular muscles. Decreased motor conduction velocities and compound muscle action potential amplitudes were detected in ulnar and sciatic-tibial nerves. Residual latency was increased in the sciatic-tibial nerve. Histologically, several intramuscular nerve branches were depleted of myelinated fibres and a few showed mononuclear infiltrations. Toxoplasma gondii serology titres were compatible with active toxoplasmosis. Four days after treatment initiation with oral clindamycin the cat recovered the ability to walk. T gondii serology titres and neurological examination were normal after 11 and 16 weeks, respectively. Clindamycin was discontinued after 16 weeks. One year after presentation the cat showed mild relapse of clinical signs and seroconversion, which again resolved following treatment with clindamycin. RELEVANCE AND NOVEL INFORMATION: To our knowledge, this is the first report of distal polyneuropathy associated with toxoplasmosis in a cat. This case suggests the inclusion of toxoplasmosis as a possible differential diagnosis for acquired polyneuropathies in cats.

Feline ischaemic myelopathy with a predilection for the cranial cervical spinal cord in older cats.

All previous studies on feline ischaemic myelopathy (IM) have reported an acute onset of a single event with no recurrence of clinical signs. This study aimed to evaluate clinical and long-term follow-up data in cats presumptively diagnosed with cervical IM in the territory of the ventral spinal artery (VSA). Eight cats (four females and four males) were included with a mean age of 14 years and 2 months. Neurological status at the time of presentation ranged from ambulatory tetraparesis to tetraplegia with nociception present. Six cats had marked cervical ventroflexion. All eight cats were diagnosed with one or more concurrent medical conditions, including chronic kidney disease (n = 2), hypertrophic cardiomyopathy (n = 2) and hypertension (n = 6). Median time to ambulation was 5.7 days (range 2-14 days). Long-term follow-up ranged from 7 months to 3 years and 3 months (median 1 year and 2 months). Five cats had no reported recurrence of clinical signs and 3/8 had a chronic relapsing disease course. One cat had an acute recurrence of clinical signs 4 months after the first event and was euthanased. Two cats had acute onsets of suspected intracranial infarctions, one of which had further suspected intracranial infarcts every 3 months and was euthanased after one of these. This study highlights the importance of performing ancillary diagnostic tests in older cats presenting with IM, particularly when VSA embolisation is suspected.

Missense mutation in CAPN1 is associated with spinocerebellar ataxia in the Parson Russell Terrier dog breed.

Spinocerebellar ataxia (SCA) in the Parson Russell Terrier (PRT) dog breed is a disease of progressive incoordination of gait and loss of balance. Clinical signs usually become notable between 6 and 12 months of age with affected dogs presenting with symmetric spinocerebellar ataxia particularly evident in the pelvic limbs. The degree of truncal ataxia, pelvic limb hypermetria and impaired balance is progressive, particularly during the initial months of disease. A certain degree of stabilisation as well as intermittent worsening may occur. At the later stages of the disease ambulation often becomes difficult, with owners often electing to euthanise affected dogs on welfare grounds. Using a GWAS approach and target-enriched massively-parallel sequencing, a strongly associated non-synonymous SNP in the CAPN1 gene, encoding the calcium dependent cysteine protease calpain1 (mu-calpain), was identified. The SNP is a missense mutation causing a cysteine to tyrosine substitution at residue 115 of the CAPN1 protein. Cysteine 115 is a highly conserved residue and forms a key part of a catalytic triad of amino acids that are crucial to the enzymatic activity of cysteine proteases. The CAPN1 gene shows high levels of expression in the brain and nervous system and roles for the protein in both neuronal necrosis and maintenance have been suggested. Given the functional implications and high level of conservation observed across species, the CAPN1 variant represents a provocative candidate for the cause of SCA in the PRT and a novel potential cause of ataxia in humans.

Clinical outcome in 19 cats with clinical and magnetic resonance imaging diagnosis of ischaemic myelopathy (2000-2011).

Previous publications on ischaemic myelopathy in cats are limited to single case reports and small case series. The overall prognosis appears poor, with 42% of cats being euthanased. In this study the clinical outcome of 19 cats with a presumptive diagnosis of ischaemic myelopathy [based on clinical and magnetic resonance imaging (MRI) findings] was evaluated retrospectively. The degree of neurological dysfunction at the time of presentation was similar to previously reported cases, ranging from ambulatory paresis to plegia with intact nociception. The most common lesion localisations (based on MRI) were to the C1-C5 (30%) and C6-T2 (30%) spinal cord segments, with the T3-L3 and L4-S1 spinal cord segments accounting for 25% and 15%, respectively. Potential inciting or predisposing causes for development of spinal infarction were identified in 12 cats, including physical exertion, trauma, general anaesthesia, renal disease, hyperthyroidism, hypertension and hypertrophic cardiomyopathy. The median time to recovery of ambulation was 3.5 days (3-19 days). Four cats (21%) were euthanased within 2 months of diagnosis. The remaining 15 (79%) cats had a favourable outcome. Follow-up ranged from 6 months to 10 years and 4 months, with a median of 3 years and 1 month. Even when plegia was present at the time of presentation, all surviving cats with long-term, owner-derived follow-up were reported to return to a normal quality of life, suggesting that the long-term prognosis for recovery from presumed ischaemic myelopathy is favourable in the majority of cats.

Developmental changes in voltage-gated calcium channel α(2)δ-subunit expression in the canine dorsal root ganglion.

The voltage-gated calcium channel subunit α(2)δ plays a fundamental role in propagation of excitatory signals associated with release of glutamate and neuropeptides substance P (SP) and calcitonin gene-related protein (CGRP). It can be selectively inhibited by gabapentinoids. Hence, investigation of the α(2)δ subunit may predict the efficacy of gabapentinoid therapy in neuropathic pain. Since sensory processing underlies significant age-related changes, this study was conducted in order to elucidate the role of the α(2)δ subunit in the sensory transmission during canine development. Dorsal root ganglia (DRG) were harvested from four spinal segments of 16 puppies and 10 adult dogs without a history of neurological signs, pain, spinal disease or orthopedic disorders. α(2)δ-Subunit expression and coexpression with SP and CGRP was evaluated immunohistochemically regarding the number of immunopositive ganglion cells, staining intensity and subcellular distribution. All tested ganglia were immunopositive for α(2)δ. Cell counts and expression levels were significantly lower in pups than in adult dogs (p < 0.05). In the cervical segments of both groups, the number and percentage of immunopositive neurons was significantly higher than in lumbar DRG (p < 0.05). Multilabeling studies in all tested animals confirmed the coexpression of α(2)δ and pain peptides SP and CGRP. This anatomical study for the first time documents the involvement of α(2)δ subunits in sensory signal processing in dogs. The proportion of positive neurons and the intracellular expression levels show a net increase from early postnatal life to adulthood. A significant portion of α(2)δ-positive cells in the dogs exhibited C- and Aδ-phenotypes compatible with nociceptive neurons. The coexpression of α(2)δ, SP and CGRP imply that these neurons are involved with peptidergic nociception. The cervicolumbar gradient of α(2)δ expression in adults reflects functional differences in between forelimbs and hind limbs. These data will facilitate translational studies on neuropathic pain states in this species such as common canine nerve entrapment syndromes.