Clinical presentation, diagnostic findings and outcome of dogs undergoing surgical resection for intracranial meningioma: 101 dogs.

BACKGROUND: Meningioma is the most common primary brain neoplasm in dogs. Further information is required regarding the expected long-term prognosis of dogs following the surgical resection of an intracranial meningioma together with the influence of adjunctive therapies. Whilst there have been several studies reporting the long-term outcome of intracranial meningioma resection following surgery alone, surgery with the use of an ultrasonic aspirator, surgery combined with radiotherapy and surgery combined with the addition of hydroxyurea, it is currently unclear which type of adjunctive therapy is associated with the most favourable outcomes. The objective of this study is to describe the presentation and outcome of dogs undergoing surgery for the resection of an intracranial meningioma and the effect of clinical factors, adjunctive therapies and meningioma histopathological subtype on the long-term outcome. RESULTS: A hundred and one dogs that had intracranial surgery for meningioma resection were investigated from four referral centres. 94% of dogs survived to hospital discharge with a median survival time of 386 days. Approximately 50% of dogs survived for less than a year, 25% survived between 1 and 2 years, 15% survived between 2 and 3 years and 10% survived for greater than 3 years following discharge from hospital. One or more adjunctive therapies were used in 75 dogs and the analysis of the data did not reveal a clear benefit of a specific type of adjunctive therapy. Those dogs that had a transfrontal approach had a significantly reduced survival time (MST 184 days) compared to those dogs that had a rostrotentorial approach (MST 646 days; p < 0.05). There was no association between meningioma subtype and survival time. CONCLUSIONS: This study did not identify a clear benefit of a specific type of adjunctive therapy on the survival time. Dogs that had a transfrontal approach had a significantly reduced survival time. Intracranial surgery for meningioma resection offers an excellent prognosis for survival to discharge from hospital with a median long term survival time of 386 days.

MRI Features of Solitary Vertebral Masses in Dogs: 20 Cases (2010-2019).

The objective of the study was to describe the MRI features of cytologically or histologically diagnosed solitary vertebral masses in dogs and identify potential MRI features enabling differentiation between malignant and benign lesions. Patients were divided into malignant and benign groups according to the final diagnosis. Medical records and MRI studies were retrospectively reviewed, and specific imaging features were compared. The malignant group comprised 15 dogs, with 5 dogs included in the benign group. MRI features of the different histopathologic/cytologic types of masses are described. Involvement of the vertebral body, a hyperintense signal on T2-weighted, short tau inversion recovery, T1-weighted, and T1-weighted gradient echo sequences and evidence of cortical destruction were signifi-cantly associated with malignancy (P < .05). Hypointensity on T1-weighted gradient echo sequence was significantly associated with benign masses (P < .05). The presence of bone sclerosis was significantly associated with osteosarcomas compared with other malignant masses (P < .05). Fractures (5 cases) were only seen in the group of malignant masses. This pilot study identifies some MRI features that may help differentiate between malignant and benign solitary vertebral masses. Greater case numbers are needed in future studies.

A genome-wide association study identifies candidate loci associated to syringomyelia secondary to Chiari-like malformation in Cavalier King Charles Spaniels.

BACKGROUND: Syringomyelia (SM) is a common condition affecting brachycephalic toy breed dogs and is characterized by the development of fluid-filled cavities within the spinal cord. It is often concurrent with a complex developmental malformation of the skull and craniocervical vertebrae called Chiari-like malformation (CM) characterized by a conformational change and overcrowding of the brain and cervical spinal cord particularly at the craniocervical junction. CM and SM have a polygenic mode of inheritance with variable penetrance. RESULTS: We identified six cranial T1-weighted sagittal MRI measurements that were associated to maximum transverse diameter of the syrinx cavity. Increased syrinx transverse diameter has been correlated previously with increased likelihood of behavioral signs of pain. We next conducted a whole genome association study of these traits in 65 Cavalier King Charles Spaniel (CKCS) dogs (33 controls, 32 with extreme phenotypes). Two loci on CFA22 and CFA26 were found to be significantly associated to two traits associated with a reduced volume and altered orientation of the caudal cranial fossa. Their reconstructed haplotypes defined two associated regions that harbor only two genes: PCDH17 on CFA22 and ZWINT on CFA26. PCDH17 codes for a cell adhesion molecule expressed specifically in the brain and spinal cord. ZWINT plays a role in chromosome segregation and its expression is increased with the onset of neuropathic pain. Targeted genomic sequencing of these regions identified respectively 37 and 339 SNPs with significantly associated P values. Genotyping of tagSNPs selected from these 2 candidate loci in an extended cohort of 461 CKCS (187 unaffected, 274 SM affected) identified 2 SNPs on CFA22 that were significantly associated to SM strengthening the candidacy of this locus in SM development. CONCLUSIONS: We identified 2 loci on CFA22 and CFA26 that contained only 2 genes, PCDH17 and ZWINT, significantly associated to two traits associated with syrinx transverse diameter. The locus on CFA22 was significantly associated to SM secondary to CM in the CKCS dog breed strengthening its candidacy for this disease. This study will provide an entry point for identification of the genetic factors predisposing to this condition and its underlying pathogenic mechanisms.

Sacrocaudal (sacrococcygeal) intervertebral disc protrusion in 2 cats.

One cat was presented for investigation of urinary retention and constipation and a second cat was presented with decreased appetite, reluctance to jump, reduced level of activity, and constipation. Magnetic resonance imaging revealed dorsal bulging of the hypo-intense intervertebral disc at S3-Cd1 on fast spin echo T2. Dorsal laminectomy was performed and both cats recovered with resolution of neurological signs.

Protrusion discale sacrocaudale (sacrococcygienne) chez 2 chats. Le chat 1 a été présenté en consultation pour exploration d'une rétention urinaire et constipation. Le chat 2 a été présenté en consultation pour baisse d'appétit, réticence à sauter, activité réduite et constipation. L'IRM a mis en évidence une protrusion dorsale du matériel discal hypointense au niveau de S3-Cd1 en fast spin echo T2. Une laminectomie dorsale a été réalisée chez ces deux chats chez qui une complète rémission clinique a été observée.(Traduit par les auteurs).

Magnetic resonance imaging features of leukoaraiosis in elderly dogs.

Leukoaraiosis is a descriptive term used to designate bilateral, symmetrical, white matter lesions identified in brains of elderly human patients. These lesions are isointense to normal in magnetic resonance imaging (MRI) T1-weighted pulse sequences, non-contrast enhancing, and hyperintense in T2-weighted and FLAIR pulse sequences. Pathophysiologic mechanisms for leukoaraiosis remain incompletely understood; however, an ischemic origin is currently being favored. Age-related changes, such as brain atrophy, ventricular enlargement, and well-demarcated sulci, have also been previously described in dogs over 9 years of age. Objectives of this retrospective case series study were to describe MRI features of leukoaraiosis and brain atrophy in a group of elderly dogs. The Dick White Referrals MRI database between October 2009 and April 2016 was reviewed. Dogs with bilaterally symmetrical periventricular areas of T2 and FLAIR hyperintensity compatible with leukoaraiosis, and older than 9 years, were included. Fourteen dogs met the inclusion criteria, with a total of 18 MRI studies available for review. Median age for sampled dogs was 13 years. Ten dogs had MRI signs of concurrent brain atrophy; one of them had signs of brain atrophy before leukoaraiotic changes could be identified. In those cases where serial MRIs were available, progressive reduction of interthalamic adhesion thickness was observed. The current study introduces leukoaraiosis as a descriptive term for the MRI sign of bilaterally symmetrical, periventricular T2, and FLAIR hyperintensities in brains of elderly dogs. Future studies are needed to determine pathophysiologic mechanisms for this MRI sign.

Feline meningoencephalomyelitis of unknown origin: A retrospective analysis of 16 cases.

This study aimed to describe the signalment, clinical signs, magnetic resonance imaging (MRI) findings, cerebrospinal fluid (CSF) analysis, treatment, and outcome of feline meningoencephalomyelitis of unknown origin (FMUO). Medical records from 16 cats meeting the inclusion criteria of CSF pleocytosis, negative CSF polymerase chain reaction (PCR)-infectious disease results, and characteristic MRI findings were retrospectively reviewed. Median age was 9.4 years. Clinical signs included ataxia, proprioceptive deficits, seizures, and spinal hyperesthesia. The CSF nucleated cell count was increased (median 70.7 cells/µL), with predominantly mixed pleocytosis and CSF protein concentration was increased in 15/16 cats. Magnetic resonance imaging showed intraparenchymal infiltrative ill-defined lesions in 13 cases. All cats received a corticosteroid-based treatment protocol; additional therapies included lomustine, cytarabine, and anticonvulsant medications. Mild neurological signs were recorded in 5/12 cats but 7/12 cats were neurologically normal at re-examination. This represents the first study of feline MUO, highlighting FMUO as an important differential diagnosis in cats with variable neurological presentation. Prognosis appears to be good with immunomodulatory therapy.

Méningo-encéphalomyélite féline d'origine inconnue : une analyse rétrospective de 16 cas. Cette étude visait à décrire le signalement, les signes cliniques, les résultats de l'imagerie par résonance magnétique (IRM), l'analyse du liquide céphalorachidien (LCR), le traitement et l'issue de la méningo-encéphalomyélite féline d'origine inconnue (MEOI). Les dossiers médicaux de 16 chats répondant aux critères d'inclusion de la pléocytose du LCR, les résultats négatifs du LCR pour des maladies infectieuses par amplification en chaîne par polymérase (ACP) et les constatations caractéristiques par IRM ont été évalués rétrospectivement. L'âge médian était de 9,4 ans. Les signes cliniques incluaient l'ataxie, les déficits proprioceptifs, les crises d'épilepsie et l'hyperesthésie spinale. La numération des cellules nucléées du LCR a augmenté (médiane de 70,7 cellules/µL), avec une pléocytose à prédominance mixte et la concentration de protéine du LCR était accrue chez 15/16 chats. L'imagerie par résonance magnétique a montré des lésions infiltrantes intraparenchymateuses mal définies dans 13 cas. Tous les chats ont reçu un protocole de traitement à base de corticostéroïde; les thérapies additionnelles incluaient la lomustine, la cytarabine et des médicaments anticonvulsifs. De légers signes neurologiques ont été observés chez 5/12 chats, mais 7/12 chats étaient neurologiquement normaux lors du réexamen. Cela représente la première étude de la MOI, ce qui souligne que la MOI est un diagnostic différentiel important chez les chats ayant une présentation neurologique variable. Le pronostic semble bon avec la thérapie immunomodulatoire.(Traduit par Isabelle Vallières).

IMAGING DIAGNOSIS-MAGNETIC RESONANCE IMAGING FEATURES OF CRANIOMANDIBULAR OSTEOPATHY IN AN AIREDALE TERRIER.

An Airedale Terrier was presented for evaluation of depression and reluctance to be touched on the head. Magnetic resonance (MR) imaging of the head was performed. The images revealed bone lesions affecting the calvarium at the level of the coronal suture and left mandibular ramus, with focal cortical destruction, expansion, and reactive new bone formation. Skull lesions were hypointense on T1-weighted sequences, hyperintense on T2-weighted sequences, and showed an intense and homogeneous enhancement after gadolinium administration. Reactive new bone formation and periosteal proliferation were confirmed histopathologically. The clinical signs, imaging findings, and histopathological examination were consistent with craniomandibular osteopathy.

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.

Presumed canine trigemino-abducens synkinesis in a dog.

A ten-year-old male neutered Rhodesian ridgeback cross dog was presented for the investigation of abnormal bilateral protrusion of the third eyelid when chewing. Physical, ophthalmological, and neurological examinations were unremarkable. Thoracic radiographs, abdominal ultrasound, and magnetic resonance of the brain and orbits failed to reveal any abnormalities. Cerebrospinal fluid analysis revealed elevated protein, but the nucleated cell count was normal. trigemino-abducens synkinesis was presumptively diagnosed. Aetiopathogenesis of this condition is discussed. To the authors' knowledge, this is the first report of presumed trigemino-abducens synkinesis in a dog.

Dorsal laminectomy for the treatment of lateralised cervical intervertebral disc extrusions in dogs-Prognosis and complications.

Objective: Describe the complication rate, expected hospitalization time and prognosis associated with dorsal laminectomy for the treatment of lateralised cervical intervertebral disc extrusion (IVDE) in dogs. Methods: This is a single-center retrospective case series study. Databases were reviewed from 2012 to 2022 for dogs that had a dorsal laminectomy to treat a lateralised cervical IVDE. Dogs were excluded if additional surgical techniques were performed, or other comorbidities were found on MRI. Results: Fifty two dogs were included the study. French bulldogs represented 28.8% of the cohort. Patient median age was 6 years and median weight 15 kg. Thirty-five dogs (67.3%) presented clinical signs for <3 days and almost half (44.2%) were ambulatory but presented cervical pain and neurological deficits. Median surgical time was 85 min. Minor intraoperative complications were reported in 22 (42.3%), with hypothermia being the most common. Thirteen (25%) needed revision surgery due to persistent cervical pain with (9/13) or without (4/13) neurological deficits. Re-extrusion or persistent extrusion was found in 92.3% of cases needing surgical revision. Median hospitalization time was 6 days. Forty-seven (90.4%) cases had a good outcome. Conclusions and clinical significance: Despite the relatively high rate of intraoperative complications and cases needing revision surgery, dorsal laminectomy as surgical treatment for lateralised cervical IVDE is still associated with good long-term prognosis in most of cases. Prognosis is good even when revision surgery is necessary but expected hospitalization time seems to be higher when compared to an alternative surgical technique.

Outcomes of surgically and conservatively managed thoracolumbar and lumbosacral intervertebral disc herniations in cats.

BACKGROUND: Limited information is available regarding intervertebral disc herniation (IVDH) and its treatment in cats. OBJECTIVES: Describe outcomes after surgical or conservative treatment of cats with thoracolumbar and lumbosacral IVDH. ANIMALS: Ninety-two cats from 2 referral populations (2012-2022) with compressive IVDH between the T3 and S1 vertebrae. METHODS: Retrospective cohort study evaluating outcomes of surgical (49 cats) and conservative (36 cats) management of IVDH; 7 cats were euthanized at diagnosis. Outcome was assessed using hospital and referring veterinarian records and client questionnaires. Successful outcome was defined as regained or improved ambulation, urinary and fecal continence, and no requirement for analgesic medication. RESULTS: Incidence of IVDH during the study period was 0.44% (92/20849). Surgical treatment resulted in 62% (6 weeks) and 74% success (6 months). Conservative treatment resulted in 54% (6 weeks) and 65% success (6 months). Neurological grade at presentation was higher in cats treated surgically (median, 2; range, 1-5) than in those treated conservatively (median, 2; range, 0-4; P = .001). Regardless of treatment type, cats suffering trauma were more likely to have a successful outcome 6 weeks after treatment compared with those without history of trauma (odds ratio, 5.3; 95% confidence interval, 1.05-26.78; P = .04). Neurological deficits remained in the majority of cats for both treatment types (92%, conservative; 86%, surgical at 6 weeks). Acute-on-chronic IVDH with characteristics of both extrusion and protrusion were identified in 10% of cats. CONCLUSIONS AND CLINICAL IMPORTANCE: Conservative treatment could be as effective as surgical decompression in cats with thoracolumbar or lumbosacral IVDH.

Clinical features, treatment, and outcome of juvenile dogs with meningoencephalitis of unknown etiology.

BACKGROUND: The information relating to the outcome specifically for juvenile dogs with meningoencephalitis of unknown etiology (MUE) is lacking. OBJECTIVES: To describe the clinical presentation, diagnostic findings, treatment, and outcome in a cohort of dogs with MUE <52 weeks old. ANIMALS: Thirty-four client-owned dogs. METHODS: Multicenter retrospective case series. Records from 5 referral centers were searched. Data was extracted from the medical records and referring veterinarians were contacted for survival data if this was not available from the record. RESULTS: The mean age was 31 weeks; the youngest dog was 11 weeks and 3 dogs were <16 weeks old. Altered mentation (71%), ataxia (44%), seizures (29%), and circling (26%) were the most common presenting complaints. Neuroanatomical localization was to the forebrain (38%), multifocal (35%), brainstem (18%), and cerebellum (12%). Corticosteroid monotherapy (n = 15) and corticosteroid plus cytosine arabinoside (n = 15) were used in equal proportions. Outcome data was available for 26 dogs, 8 (31%) were alive at the time of data collection with a follow-up range of 135 to 2944 days. Death or euthanasia was related to MUE in 17/18 dogs that died during the study period. Kaplan-Meier survival analysis demonstrated a median survival time for all-cause death of 84 days. CONCLUSION: The prognosis for MUE in this subset of dogs was considered poor.

Intrathecal chemotherapy for the management of lymphoblastic lymphoma in a 4-year-old dog: a case report.

Intrathecal chemotherapy is used in human medicine for the treatment or prophylaxis of CNS hematopoietic neoplasia. However, the clinical benefits in veterinary medicine have been scarcely documented. A 4-year-old male entire cross-breed dog presented with a 24-h history of severe lethargy, pelvic limb weakness, and urinary retention. Examination revealed generalized peripheral lymphadenomegaly, and the neurological findings were suggestive of a myelopathy in the region of T3-L3. Following the diagnosis of multicentric lymphoblastic B-cell lymphoma (stage Vb), a modified L-LOP with cytosine arabinoside was started, and complete clinical remission was achieved. After 4 weeks, there was acute neurological deterioration (spinal pain and proprioceptive deficits) without peripheral lymphadenomegaly. MRI findings and CSF analysis were consistent with meningeal and spinal cord lymphoma infiltration at the level of L3. Intrathecal chemotherapy (cytosine arabinoside and methotrexate) were administered in the cisterna magna with systemic dexamethasone and analgesia. Clinical signs were resolved within 24 h, and the patient remained asymptomatic for 3.5 weeks. After this period, CNS relapse (proprioceptive deficits and severe thoracolumbar pain) was suspected, and repeat intrathecal chemotherapy was declined. The patient was humanely euthanized 9 weeks after the initial diagnosis. This is the first report on the clinical benefit of intrathecal chemotherapy with a combination of methotrexate and cytarabine for the management of CNS lymphoma in dogs. Based on our case, intrathecal chemotherapy with methotrexate and cytarabine can induce a short-lasting CNS clinical remission (3 weeks).

Accuracy of low-field magnetic resonance imaging for differentiating intervertebral disc extrusions and protrusions at the lumbosacral disc space in dogs.

Introduction/Purpose: MRI features differentiating extrusion from protrusion in thoracolumbar discs have been published, however little specifically evaluates the lumbosacral disc. The high prevalence of degenerative changes in apparently normal animals complicates assessment of this region and features relevant elsewhere in the spine may not apply. The aims of this study were to determine the accuracy of MRI in differentiating IVDE and IVDP at the lumbosacral disc space in dogs and determine which MRI characteristics discriminate between IVDE and IVDP. Method: MRI examinations from dogs with surgically confirmed IVDE or IVDP at the lumbosacral disc space were collected retrospectively (2011-2019). Two radiologists independently recorded a diagnosis of IVDE or IVDP, gave a confidence rating, and evaluated specific MRI features. Univariable statistical analysis was performed to identify which MRI characteristics might help distinguish IVDE from IVDP. Results: 117 dogs with lumbosacral IVDE (n = 16) or IVDP (n = 101) were included. Features associated with IVDE were in concordance with previous studies and included interruption of the dorsal annulus, suspected epidural hemorrhage, dispersed (rather than confined) intervertebral disc herniation on T2W sagittal images, lateralized intervertebral disc herniation and displacement of the cauda equina. Overall diagnostic accuracy was 68.8% and interobserver agreement was fair (κ = 0.37), which is lower than has been reported in thoracolumbar disc herniation, but accuracy increased to 85.3% with substantially improved agreement (κ = 0.87) in "confident" diagnoses. Discussion/Conclusion: MRI characteristics used in differentiating thoracolumbar IVDE and IVDP can be extrapolated to the lumbosacral intervertebral disc space, but diagnostic accuracy in low-field MRI is lower than previously reported in herniations involving the thoracolumbar spine.

A case series of 37 surgically managed, paraplegic, deep pain negative French bulldogs, with thoracolumbar intervertebral disc extrusion, from two English referral centres.

Background: Thoracolumbar intervertebral disc extrusions (TL-IVDEs) are a common spinal disorder in dogs, especially within chondrodystrophic breeds. Loss of deep pain perception is a well-documented negative prognostic indicator in dogs with TL-IVDE. The objectives of this study were to report the rate of return of deep pain perception and independent ambulation in surgically treated, paraplegic, deep pain perception negative French bulldogs with TL-IVDEs. Methods: A retrospective case series of deep pain perception negative dogs with TL-IVDE presenting to two referral centres between 2015 and 2020 was conducted. Medical and MRI records were reviewed, including the following quantitative MRI changes: lesion length, extent of spinal cord swelling and severity of spinal cord compression. Results: Thirty-seven French bulldogs met the inclusion criteria, with 14 of 37 (38%) regaining deep pain perception by the time of discharge (median hospitalisation 10.0 days [interquartile range 7.0-15.5 days]) with two dogs independently ambulatory (6%). Ten of the 37 dogs were euthanased during hospitalisation. Significantly fewer dogs (3/16, 19%) with L4-S3 lesions regained deep pain perception compared to 11 of 21 (52%) of dogs with T3-L3 lesions (p = 0.048). Quantitative MRI changes were not associated with the return of deep pain perception. After discharge, with a median 1-month follow-up period, an additional three dogs regained deep pain perception and five dogs became independently ambulatory (17/37 [46%] and 7/37 [19%], respectively). Conclusions and clinical importance: This study adds support to the contention that the recovery of French bulldogs with TL-IVDE from surgery is poor compared with other breeds; further prospective, breed-controlled studies are indicated.

The Olfactory Bulb in Companion Animals-Anatomy, Physiology, and Clinical Importance.

The Olfactory Bulb is a component of the Olfactory System, in which it plays an essential role as an interface between the peripheral components and the cerebral cortex responsible for olfactory interpretation and discrimination. It is in this element that the first selective integration of olfactory stimuli occurs through a complex cell interaction that forwards the received olfactory information to higher cortical centers. Considering its position in the organizational hierarchy of the olfactory system, it is now known that changes in the Olfactory Bulb can lead to olfactory abnormalities. Through imaging techniques, it was possible to establish relationships between the occurrence of changes secondary to brain aging and senility, neurodegenerative diseases, head trauma, and infectious diseases with a decrease in the size of the Olfactory Bulb and in olfactory acuity. In companion animals, this relationship has also been identified, with observations of relations between the cranial conformation, the disposition, size, and shape of the Olfactory Bulb, and the occurrence of structural alterations associated with diseases with different etiologies. However, greater difficulty in quantitatively assessing olfactory acuity in animals and a manifestly smaller number of studies dedicated to this topic maintain a lack of concrete and unequivocal results in this field of veterinary sciences. The aim of this work is to revisit the Olfactory Bulb in companion animals in all its dimensions, review its anatomy and histological characteristics, physiological integration in the olfactory system, importance as a potential early indicator of the establishment of specific pathologies, as well as techniques of imaging evaluation for its in vivo clinical exploration.

Lumbar intervertebral foraminal disc extrusion in a cat.

Case summary: A 10-year-old domestic longhair cat was presented for investigations into a 4-day history of acute-onset lethargy, hyporexia and right pelvic limb lameness. Based upon the neurological examination, a right femoral nerve localisation was suspected. Pelvic radiographs identified a dorsally displaced L5-L6 intervertebral disc, with subsequent MRI suggestive of a right L5-L6 neuritis secondary foraminal intervertebral disc extrusion. Medical management, consisting of rest and analgesia, resulted in near-complete resolution of clinical signs in 37 days. Relevance and novel information: To our knowledge, this is the first report of a lumbar foraminal intervertebral disc extrusion in a cat and should be considered on the differential list for acute-onset pelvic limb lameness in the absence of neurological deficits.

Feline temporal lobe epilepsy: seven cases of hippocampal and piriform lobe necrosis in England and literature review.

CASE SERIES SUMMARY: Seven cases of feline hippocampal and piriform lobe necrosis (FHN) are described, with particular emphasis on clinical, radiographic and histopathological correlations. FHN is an uncommon acute epileptic condition resembling human autoimmune limbic encephalitis and temporal lobe epilepsy. Seizures are typically focal and feature uni- or bilateral orofacial or head twitching, hypersalivation, lip smacking, mydriasis, vocalisation and motionless staring, with inter-ictal behavioural changes such as unprovoked aggression and rapid running. Emerging evidence supports an autoimmune aetiology, although disruption of hippocampal architecture secondary to brain neoplasia has also been recognised. Most commonly, however, the underlying cause remains unknown. Diagnosis is achieved clinically and with brain MRI; electroencephalography and voltage-gated potassium channel-complex autoantibodies are currently the subject of research. Affected cats are frequently refractory to conventional antiepileptic treatment. RELEVANCE AND NOVEL INFORMATION: Following a review of the literature, including potential complicating factors and comparisons with human medicine, the hippocampus and piriform lobe are proposed as the neuroanatomical localisation for focal seizures with orofacial involvement in cats, regardless of aetiology.

Retrospective Preliminary Assessment of Routine Follow-Up Low-Field Magnetic Resonance Imaging in Dogs Presumptively Diagnosed With Discospondylitis.

Background: The usefulness of routine follow-up Magnetic Resonance Imaging (MRI-2) in asymptomatic dogs treated for discospondylitis is unknown. Methods: This cross-sectional retrospective study investigated the features of MRI-2 in a heterogeneous group of dogs treated for discospondylitis, and if these were associated with the presence or absence of clinical signs. After comparing initial MRI (MRI-1) and MRI-2, an observer, blinded to the dog's clinical signs, described the MRI-2 findings. The study population was then divided into symptomatic or asymptomatic at the time of MRI-2. Two separate observers subjectively classified the discospondylitis as active or inactive. Repeatability and interobserver agreement were evaluated. Results: A total of 25 dogs were included. At the time of MRI-2 16 (64%) dogs were asymptomatic and 9 (36%) were symptomatic. Based on MRI-2, 20 (80%) and 18 (72%) out of 25 dogs were considered to have active discospondylitis by the first and second observers, respectively. Interobserver agreement was moderate. No MRI-2 features were associated with the clinical status. The subjective classification of inactive discospondylitis was significantly associated with asymptomatic clinical status, but the classification of active discospondylitis was evenly distributed between groups. Conclusion: This study did not identify a meaningful association between the clinical status of dogs treated for presumptive discospondylitis and MRI-2 results. There were no specific MRI-2 features which were associated with the clinical status.

Long-lasting otic medications may be a rare cause of neurogenic keratoconjunctivitis sicca in dogs.

OBJECTIVE: To characterize the clinical course and long-term prognosis of a suspected novel cause of neurogenic keratoconjunctivitis sicca (nKCS) secondary to florfenicol, terbinafine hydrochloride, mometasone furoate (Claro and Neptra) or florfenicol, terbinafine, betamethasone acetate (Osurnia). ANIMALS: 29 client-owned dogs. PROCEDURES: Online survey and word-of-mouth recruitment were conducted to identify dogs that developed clinical signs of nKCS after application of otitis externa medication containing terbinafine and florfenicol. A retrospective analysis of medical records of dogs meeting inclusion criteria was then conducted. Included dogs had onset of clinical signs of nKCS within 1 day after application of otitis externa medications containing terbinafine and florfenicol and had documentation of low Schirmer tear test value (< 15 mm/min) of affected eyes. RESULTS: 29 dogs with medical records available for review met the inclusion criteria. Documented return of clinically normal tear production was identified in 24 of 29 dogs, with a median time from application of ear medication to documented return of clinically normal tear production of 86 days (range, 19 to 482 days). A corneal ulcer was diagnosed in 68% (20/29). Multivariable Cox regression analysis showed being referred to an ophthalmologist (P = .03) and having a deep ulcer (P = .02) were associated with a longer time to documentation of Schirmer tear test ≥ 15 mm/min. CLINICAL RELEVANCE: Dogs that developed nKCS within 1 day after application of otitis externa medications containing terbinafine and florfenicol had a good prognosis for return of normal tear production within 1 year.