Spontaneous resorption of a herniated cervical disc in a dog detected by magnetic resonance imaging.

This report describes, for the first time in small animal literature, the spontaneous resorption of herniated Hansen type I intervertebral disc material in the cervical spine of a chondrodystrophic dog over a 4-month period, documented by magnetic resonance imaging. Clinical signs (cervical hyperpathia) responded to conservative treatment during the same period.

Résorption spontanée d'une hernie discale chez un chien détectée par imagerie par résonance magnétique. Cet article décrit, pour la première fois dans la littérature des petits animaux, la résorption spontanée d'une hernie Hansen de type I du matériel du disque intervertébral dans la colonne cervicale d'un chien chondrodystrophique pendant une période de 4 mois et documentée par imagerie par résonance magnétique (IRM). Les signes cliniques (hyperpathie cervicale) ont répondu à un traitement conservateur durant la même période.(Traduit par Isabelle Vallières).

Novel approach to temporal lobectomy for removal of a cavernous hemangioma in a dog.

OBJECTIVE: To report temporal lobe surgery for a cavernous hemangioma in a dog and outcome. STUDY DESIGN: Clinical report. ANIMALS: Dog (n = 1). METHODS: Magnetic resonance (MR) imaging was used to identify a temporal lobe mass in 9-year-old, male neutered Labrador Retriever that had a 12 hour history of seizures. An approach to the temporal lobe allowed preservation of the zygomatic arch and mass removal. RESULTS: The mass was confirmed as a cavernous hemangioma on histopathology. Repeat MR imaging at 13 months showed no recurrence of gross structural disease; however, the dog's anti-epileptic medication was administered for adequate seizure control. CONCLUSION: Temporal lobe surgery can be performed in the dog's for the management of temporal lobe mass lesions.

Public perception of epilepsy in dogs is more favorable than in humans.

OBJECTIVES: With the use of YouTube™, this study provides results on both the demographics and public perception for a sample of videos of canine epilepsy. METHODS: A random sample of 150 videos was collected, the uploader description was recorded, and viewers' comments were coded according to their emotional and informational content. RESULTS: More comments were found to be sympathetic than derogatory, and there were more information-providing than information-seeking comments. The number of sympathetic comments was found to correlate positively with the number of derogatory comments, and the number of information-providing comments correlated positively with the number of information-seeking comments. CONCLUSION: These findings shed light on the variation in perceptions of seizures in dogs, which are interestingly more sympathetic towards dogs with epilepsy than towards humans with epilepsy. This highlights the potential future use of YouTube in investigating public views as well as in informing and educating.

Imaging diagnosis-malignant peripheral nerve sheath tumor presenting as an intra-axial brain mass in a young dog.

A 3-year-old Labrador retriever was presented with acute onset seizures. Magnetic resonance imaging demonstrated an intra-axial mass affecting the right temporal lobe of the brain. Surgical resection and histopathological findings were most consistent with a malignant peripheral nerve sheath tumor. After initial recovery, deterioration 3 months post surgery prompted euthanasia. Post-mortem revealed a mass protruding from the ventral surface of the temporal lobe, encroaching upon the optic chiasm and invading the brain. Histopathology findings were again consistent with malignant peripheral nerve sheath tumor. Although rare, this tumor should be included as a possible differential diagnosis for intra-axial brain masses in dogs.

Surgical treatment of an intracranial epidermoid cyst in a dog.

OBJECTIVE: To report challenges and complications associated with surgical intracranial epidermoid cyst removal from the fourth ventricle of a dog. STUDY DESIGN: Clinical report. ANIMAL: Labrador retriever (7 years old) with focal seizures. METHODS: Magnetic resonance imaging (MRI) revealed an oval lesion in the fourth ventricle. This lesion was heterogeneously hyperintense on T2-weighted and fluid attenuation inversion recovery (FLAIR) images and hypointense on T1-weighted images. Dilatation of the ventricular system was present. A ventriculoperitoneal shunt (VPS) was placed and the fourth ventricle was approached by suboccipital craniectomy. An oval, white mass was identified in the fourth ventricle. Subtotal removal of the mass was performed. RESULTS: On the day after surgery, neurologic deterioration was observed. The dog had severe cerebellar and brainstem dysfunction. Histopathologic examination of the removed tissue revealed an epidermoid cyst. The dog experienced gradual neurologic improvement; however, neurologic deterioration beginning at 6 months resulted in euthanasia 8 months after surgery. On necropsy, epidermoid cyst tissue was identified in the fourth ventricle. CONCLUSION: Surgical removal of an intracranial epidermoid cyst may be complicated by adhesions between the cyst capsule and surrounding neurovascular structures, causing postoperative morbidity and eventual recurrence of clinical signs. These observations should be taken into account when considering surgical removal of an intracranial epidermoid cyst.

Behavioral changes in dogs associated with the development of idiopathic epilepsy.

OBJECTIVES: The aim of the study was to demonstrate behavioral changes with the development of epilepsy in dogs, a species proposed as a naturally occurring animal model for human epilepsy. METHODS: Owners of dogs diagnosed with idiopathic epilepsy (n=80) completed a modified, previously-validated behavioral and seizure questionnaire. Principal axis factor analysis identified behavioral factors, the scores for which were compared before and after the development of epilepsy. RESULTS: Drug-naïve dogs showed an increase in the behavior factors Fear/Anxiety, Defensive Aggression, and Abnormal Perception. In dogs receiving antiepileptic medication, there were still increases in Fear/Anxiety and Abnormal Perception, but no longer in Defensive Aggression. Additional increases were observed in Abnormal Reactivity, Attachment Disorder, Demented Behavior, and Apathetic Behavior. Pharmacoresistant dogs had larger increases in Controlling Aggression, Abnormal Perception, and Demented Behavior than drug responders. CONCLUSION: Our data suggest that dogs, like humans and rodents, exhibit neurobehavioral comorbidities with the development of epilepsy.

Treatment of hydrocephalus with ventriculoperitoneal shunting in twelve dogs.

OBJECTIVE: To report use of ventriculoperitoneal shunt in dogs for management of hydrocephalus for which no cause could be identified. STUDY DESIGN: Case series. ANIMALS: Dogs with hydrocephalus (n=12). METHODS: Medical records (June 2003-June 2009) were reviewed to determine preoperative clinical findings, initial postoperative, and long-term outcome. Additional follow-up information was obtained from owners and referring veterinarians. RESULTS: All dogs had signs of forebrain dysfunction, 7 had vestibular signs and 3 had signs of spinal pain. Postoperative complications included pain (n=4), undershunting because of shunt kinking (n=1) and seizures (n=1). Initial improvement occurred in all dogs and was sustained in 9 dogs, 1 of which required revision surgery. CONCLUSIONS: Sustained clinical improvement can be achieved in hydrocephalus with no active underlying cause by use of ventriculoperitoneal shunting.

Comparison of interobserver agreement between the evaluation of bicipital and the patellar tendon reflex in healthy dogs.

The reliability of reflex-assessment is currently debatable, with current literature regarding the patellar tendon reflex (PTR) as highly reliable, while the biceps tendon reflex (BTR) is regarded to be of low reliability in the dog. Such statements are, however, based on subjective observations rather than on an empirical study. The goals of this study were three-fold: (1) the quantification of the interobserver agreement (IA) on the evaluation of the canine bicipital (BTR) and patellar tendon (PTR) reflex in healthy dogs, (2) to compare the IA of the BTR and PTR evaluation and (3) the identification of intrinsic (sex, age, fur length, weight) and extrinsic (observer´s expertise, body side) risk factors on the IA of both reflexes. The observers were subdivided into three groups based on their expected level of expertise (neurologists = highest -, practitioners = middle-and veterinary students = lowest level of expertise). For the BTR, 54 thoracic limbs were analyzed and compared to the evaluation of the PTR on 64 pelvic limbs. Each observer had to evaluate the reflex presence (RP) (present or absent) and the reflex activity (RA) using a 5-point ordinal scale. Multiple reliability coefficients were calculated. The influence of the risk factors has been calculated using a mixed regression-model. The Odds Ratio for each factor was presented. The higher the level of expertise the higher was the IA of the BTR. For RP(BTR), IA was highest for neurologists and for RA(BTR) the IA was lowest for students. The level of expertise had a significant impact on the degree of the IA in the evaluation of the bicipital tendon reflex: for the RA(BTR), practitioners had a 3.4-times (p = 0.003) and students a 7.0-times (p < 0.001) higher chance of discordance. In longhaired dogs the chance of disagreement was 2.6-times higher compared to shorthaired dogs in the evaluation of RA(BTR) (p = 0.003). Likewise, the IA of the RP(PTR) was the higher the higher the observers´ expertise was with neurologists having significantly highest values (p < 0.001). The RA(PTR) has been evaluated more consistent by practitioners and students than the RA(BTR). For practitioners this difference was significant (< 0.01). Our data suggests that neurologists assess the bicipital and patellar tendon reflex in dogs most reliably. None of the examined risk factors had a significant impact on the degree of IA in the evaluation of RP(PTR), while students had a 4.4-times higher chance of discordance when evaluating the RA(PTR) compared to the other groups. This effect was significant (p < 0.001). Neurologists can reliably assess the bicipital and patellar tendon reflex in healthy dogs. Observer´s level of expertise and the fur length of the dog affect the degree of IA of RA(BTR). The influence of the observer´s expertise is higher on the evaluation of the BTR than on the PTR.

Levetiracetam monotherapy for treatment of structural epilepsy in dogs: 19 cases (2010-2015).

To evaluate the efficacy and tolerability of levetiracetam monotherapy in dogs with structural epilepsy. Retrospective case series. Nineteen client-owned dogs with structural epilepsy. Seizure frequencies after initiation of treatment were used to evaluate the efficacy of levetiracetam monotherapy. Seizure control was considered good if no seizures occurred within three months of starting treatment or poor if seizures returned within one month of starting treatment. Tolerability was evaluated by considering the occurrence and severity of any reported side effects. Ten of the 19 dogs were considered to have a good response to treatment with 7 achieving complete seizure freedom. Nine dogs were considered to have poor response to treatment. There was a statistically significant reduction in the percentage of patients experiencing cluster seizures from 68.4% to 15.8% (p=0.002). Side effects were noted in 8 of the 19 dogs but were considered mild in all cases. Follow-up times ranged from 12 days to 426 days. When used in conjunction with other appropriate therapies, levetiracetam may be an efficacious option for monotherapy in dogs with structural epilepsy. Its tolerability makes it a suitable option for use in a wide variety of patients.

A case of acute acquired obstructive hydrocephalus in a cat with suspected ischaemic cerebellar infarct.

CASE SUMMARY: A case of acquired acute obstructive hydrocephalus that developed as a complication of an ischaemic infarct in the vascular territory of the rostral cerebellar artery is described in an adult domestic shorthair cat. The clinical findings, diagnostic investigations, treatment and prognosis are reported. MRI findings are described in detail. RELEVANCE AND NOVEL INFORMATION: This is the first report of obstructive hydrocephalus as a complication of an ischaemic infarct in the region of the rostral cerebellar artery in a cat. MRI findings are described in detail with regard to the recognition of the early signs of obstructive hydrocephalus. A brief review of the literature is included, as this complication has been frequently reported in humans.

Risk factors for cluster seizures in canine idiopathic epilepsy.

Cluster seizures (CS), two or more seizures within a 24-hour period, are reported in 38-77% of dogs with idiopathic epilepsy (IE). Negative outcomes associated with CS include a reduced likelihood of achieving seizure freedom, decreased survival time and increased likelihood of euthanasia. Previous studies have found factors including breed, sex and neuter status are associated with CS in dogs with IE; however, only one UK study in a multi-breed study of CS in IE patients exists to the author's knowledge, and thus further data is required to confirm these results. Data from 384 dogs treated at a multi-breed canine specific epilepsy clinic were retrospectively collected from electronic patient records. 384 dogs were included in the study, of which nearly half had a history of CS (49.1%). Dogs with a history of CS had a younger age at onset than those without (p = 0.033). In a multivariate model, three variables predicted risk of CS: a history of status epilepticus (p = 0.047), age at seizure onset (p = 0.066) and breed (German Shepherd Dog) (p < 0.001). Dogs with a history of status epilepticus and dogs with an older age at seizure onset were less likely to be affected by cluster seizures. German Shepherd Dogs (71% experiencing CS) were significantly more likely to suffer from CS compared to Labrador Retrievers (25%) (p < 0.001). There was no association between sex, neuter status, body size and CS. Further studies into the pathophysiology and genetics of CS are required to further understand this phenomenon.

Clinical risk factors associated with anti-epileptic drug responsiveness in canine epilepsy.

The nature and occurrence of remission, and conversely, pharmacoresistance following epilepsy treatment is still not fully understood in human or veterinary medicine. As such, predicting which patients will have good or poor treatment outcomes is imprecise, impeding patient management. In the present study, we use a naturally occurring animal model of pharmacoresistant epilepsy to investigate clinical risk factors associated with treatment outcome. Dogs with idiopathic epilepsy, for which no underlying cause was identified, were treated at a canine epilepsy clinic and monitored following discharge from a small animal referral hospital. Clinical data was gained via standardised owner questionnaires and longitudinal follow up data was gained via telephone interview with the dogs' owners. At follow up, 14% of treated dogs were in seizure-free remission. Dogs that did not achieve remission were more likely to be male, and to have previously experienced cluster seizures. Seizure frequency or the total number of seizures prior to treatment were not significant predictors of pharmacoresistance, demonstrating that seizure density, that is, the temporal pattern of seizure activity, is a more influential predictor of pharmacoresistance. These results are in line with clinical studies of human epilepsy, and experimental rodent models of epilepsy, that patients experiencing episodes of high seizure density (cluster seizures), not just a high seizure frequency pre-treatment, are at an increased risk of drug-refractoriness. These data provide further evidence that the dog could be a useful naturally occurring epilepsy model in the study of pharmacoresistant epilepsy.

How long and low can you go? Effect of conformation on the risk of thoracolumbar intervertebral disc extrusion in domestic dogs.

Intervertebral disc extrusion (IVDE) is a common neurological disorder in certain dog breeds, resulting in spinal cord compression and injury that can cause pain and neurological deficits. Most disc extrusions are reported in chondrodystrophic breeds (e.g. Dachshunds, Basset Hounds, Pekingese), where selection for 'long and low' morphologies is linked with intervertebral discs abnormalities that predispose dogs to IVDE. The aim of this study was to quantify the relationship between relative thoracolumbar vertebral column length and IVDE risk in diverse breeds. A 14 month cross-sectional study of dogs entering a UK small animal referral hospital for diverse disorders including IVDE was carried out. Dogs were measured on breed-defining morphometrics, including back length (BL) and height at the withers (HW). Of 700 dogs recruited from this referral population, measured and clinically examined, 79 were diagnosed with thoracolumbar IVDE following diagnostic imaging ± surgery. The BL:HW ratio was positively associated with IVDE risk, indicating that relatively longer dogs were at increased risk, e.g. the probability of IVDE was 0.30 for Miniature Dachshunds when BL:HW ratio equalled 1.1, compared to 0.68 when BL:HW ratio equalled 1.5. Additionally, both being overweight and skeletally smaller significantly increased IVDE risk. Therefore, selection for longer backs and miniaturisation should be discouraged in high-risk breeds to reduce IVDE risk. In higher risk individuals, maintaining a lean body shape is particularly important to reduce the risk of IVDE. Results are reported as probabilities to aid decision-making regarding breed standards and screening programmes reflecting the degree of risk acceptable to stakeholders.

Neuromuscular disorders in the cat: clinical approach to weakness.

PRACTICAL RELEVANCE: Weakness is a relatively common clinical presentation in feline medicine and can be caused by primary neuromuscular disease or by diseases of other body systems affecting the neuromuscular system secondarily. Successful work-up relies on a thorough clinical and neurological examination, and logical problem solving, based on an understanding of the underlying neuroanatomical and pathophysiological mechanisms. CLINICAL CHALLENGES: Feline neuromuscular diseases can be a diagnostic challenge. On initial inspection, the presenting signs can mimic disorders of other body systems, particularly cardiovascular, pulmonary and orthopaedic disease, or may be confused with systemic illnesses. Additionally, because many different pathologies of the feline neuromuscular system converge to a similar clinical phenotype, further diagnostic steps such as electrodiagnostics, cerebrospinal fluid analysis, and muscle and nerve biopsies must be considered even after neuromuscular dysfunction has been identified. AUDIENCE: This review provides a framework for the clinical approach to the weak cat and gives a practical summary of neuromuscular diseases for the general practitioner and specialist alike. EVIDENCE BASE: Many diseases affecting the feline neuromuscular system have been well described in the veterinary literature, mostly based on retrospective case reports and series. The evidence base for the treatment of feline neuromuscular diseases remains very limited.

Surgical management of an incidentally diagnosed true pleuroperitoneal hernia in a cat.

Diaphragmatic defects in cats are common and most frequently occur as a result of trauma. Congenital diaphragmatic defects include peritoneopericardial hernias, hiatal hernias and, infrequently, true diaphragmatic, or pleuroperitoneal, hernias. Only three reports of feline pleuroperitoneal hernias could be found in the veterinary literature. All of these cats presented for evaluation of respiratory distress and two were managed successfully with surgery. This report describes the incidental diagnosis and successfully surgical treatment of a pleuroperitoneal hernia in a cat. It highlights the fact that pleuroperitoneal hernias may not always be symptomatic and that they may not be as rare as previously considered.