Clinical description with magnetic resonance appearance of a high-grade undefined optic nerve glioma with intracranial extension.

A 4-year-old mixed-breed dog was presented for hyphema and glaucoma of the right eye. Enucleation of the right globe was carried out, and histopathology examination revealed an optic nerve glioma with incomplete surgical margins. At 8 wk after surgery, the dog had depressed mentation and a diminished pupillary light reflex of the left eye. Magnetic resonance imaging revealed an irregular, heterogeneously T2 hyperintense/T1 isointense mass in the region of the optic chiasm. Compression of the rostral thalamus was present, with effacement of the pituitary gland and involvement of the right orbit. The dog was euthanized 4.5 mo after initial presentation. An undefined glioma of the right optic nerve with extension to the diencephalon was diagnosed on necropsy. Key clinical message: Although rare, intraocular glioma is a differential diagnosis for hyphema, glaucoma, and retinal detachment. Magnetic resonance imaging should be considered in cases of intraocular neoplasia, notably in those with incomplete surgical margins of the optic nerve.

Description clinique avec aspect en résonance magnétique d'un gliome indéfini de haut grade du nerf optique avec extension intracrânienne. Un chien de race croisé âgé de 4 ans a été présenté pour un hyphéma et un glaucome de l'œil droit. Une énucléation du globe droit a été réalisée et l'examen histopathologique a révélé un gliome du nerf optique aux marges chirurgicales incomplètes. Huit semaines après la chirurgie, le chien avait une diminution du processus mental et un réflexe pupillaire à la lumière diminué de l'œil gauche. L'imagerie par résonance magnétique a révélé une masse irrégulière hétérogène hyperintense T2/T1 isointense dans la région du chiasma optique. Une compression du thalamus rostral était présente, avec effacement de l'hypophyse et atteinte de l'orbite droite. Le chien a été euthanasié 4,5 mois après la présentation initiale. Un gliome indéfini du nerf optique droit avec extension au diencéphale a été diagnostiqué à l'autopsie.Message clinique clé:Bien que rare, le gliome intraoculaire est un diagnostic différentiel pour l'hyphéma, le glaucome et le décollement de la rétine. L'imagerie par résonance magnétique doit être envisagée en cas de néoplasie intraoculaire, notamment chez ceux dont les marges chirurgicales du nerf optique sont incomplètes.(Traduit par Dr Serge Messier).

Urinary syndecan-1 in dogs anesthetized with isoflurane or sevoflurane: A randomized, prospective study.

BACKGROUND: Syndecan-1 (SDC1) is an established marker of endothelial glycocalyx shedding. Most research on SDC1 has focused on plasma or serum concentrations, and little is known about urine concentrations. OBJECTIVES: Measure urinary SDC1 concentrations in dogs undergoing anesthesia with either sevoflurane or isoflurane and assess the effects of anesthesia duration and IV crystalloids on urinary SDC1 concentrations. ANIMALS: Thirty-one client-owned dogs undergoing anesthesia for magnetic resonance imaging (MRI) with or without surgery for suspected intervertebral disk disease (IVDD) were used. METHODS: Dogs with suspected IVDD were randomized to undergo anesthesia with either sevoflurane or isoflurane. Urine was collected before and immediately after anesthesia for the analysis of SDC1. Urinary creatinine concentrations also were measured, and the ratio of urinary SDC1 to urinary creatinine (USCR) was used to account for dilution. RESULTS: Median (range) USCR was significantly higher after anesthesia compared with baseline for all groups combined (P < .05). No significant difference was found between the groups for age, sex, weight, and type of anesthesia. Multiple regression analysis of the effect of the independent variables inhalant type, age, weight, sex, anesthesia time, surgery, and quantity of IV fluids on the dependent variable SDC1 found that only the quantity of IV fluids significantly predicted a change (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: The total volume of lactated Ringer's solution administered to anesthetized dogs may affect USCR. Further investigations are warranted to evaluate the relationship between IV fluids and SDC1.

Pharmacokinetics and tolerability of a veterinary phenobarbital product in healthy dogs.

Introduction: Phenobarbital has been used for many decades in both human and veterinary epileptic patients. Many formulations for a particular drug exist, most of which are marketed for humans. Recently a veterinary specific phenobarbital product has been introduced to the market in the United States. Utilizing a specific formulation to treat patients may help decrease the issue of bioequivalence between one pharmaceutical product to another. Therefore, the goal of this study was to determine single and multiple dosing pharmacokinetics and tolerability of a veterinary specific phenobarbital product over a 4-week time period. Materials and methods: 8 Healthy dogs from a canine research colony were used in the study. Results: Overall, this phenobarbital formulation was well tolerated in the dogs in this study. Cmax, Tmax, half-life, and AUC after single 12 mg/kg oral dose were 23.5 µg/mL, 4.2 h, 94 h, and 2,758 h*µg/mL. Following chronic dosing, these parameters were 29.1 µg/mL, 3.4 h, 70 h, and 2,971 h*µg/mL, respectively. Discussion: This formulation demonstrated a mean absolute bioavailability of 100%, with similar pharmacokinetic properties to previously published data.

Case report: Recovery and sequential imaging of a patient with osmotic demyelination syndrome.

A 4-year-old neutered-male Australian Shepherd was presented to an emergency and referral hospital for an acute onset of neurologic signs and abnormal mentation. Seven days prior, the patient had been diagnosed with hypoadrenocorticism and was treated accordingly at another hospital. Based on recent clinical history, the neurologic signs were consistent with thalamic and brainstem deficits and suspected to be caused by osmotic demyelination syndrome secondary to rapid correction of hyponatremia. A brain MRI confirmed lesions consistent with osmotic demyelination syndrome. The patient's clinical signs initially worsened, and he required intensive nursing care with multimodal sedation, close monitoring of electrolytes and tailored fluid therapy. The patient recovered and was discharged on day seven of hospitalization. Four and a half months later, re-evaluation of the patient showed complete resolution of the neurological deficits with a now unremarkable neurological exam, and follow-up MRI revealed still present, yet improved bilateral thalamic lesions. This is the first known veterinary case report of sequential brain imaging of a dog that has recovered from osmotic demyelination syndrome. In humans, patients can have evidence of near to full clinical recovery, yet imaging findings may still be abnormal several months after recovery. This report details similar imaging findings in a canine with improved clinical signs, despite persistent lesions on brain MRI. Prognosis of canines with osmotic demyelination syndrome may be better than previously perceived, despite the severity of clinical signs and brain lesions apparent on MRI.

Disposition of a single oral dose of a cannabidiol medication in healthy cats.

The historical use of the marijuana plant for medicinal purposes is long. One of the historical uses has been for the treatment of epilepsy. Recently, the Food and Drug Administration has approved a highly purified cannabidiol medication for the add on therapy in people with certain forms of epilepsy. With the increase interest of the use of cannabidiol in the veterinary community, the aim of this study was to describe the disposition of a single dose of a cannabidiol medication in healthy cats in both the fed and fasted state. Pharmacokinetic analysis reveals that relative bioavailability of cannabidiol shows a near eleven-fold increase when administered in the fed state compared to the fasted state. Additionally, concentrations achieved at a dose of 5 mg/kg, may be sufficient to explore the therapeutic potential in cats with epilepsy.

Case report: Intraneural perineurioma in dogs: a case series and brief literature review.

Intraneural perineurioma is an exceptionally rare neoplasm in animals. This case study comprises a series of three cases and a brief literature review focusing on canine intraneural perineurioma. The pathological and immunohistochemical findings are documented, revealing that canine intraneural perineurioma frequently affects adult dogs aged between 3 and 10 years old, with a male predominance. Clinical signs associated with intraneural perineurioma in dogs include spinal pain, lameness, and paresis, resulting from the involvement of spinal nerve roots of the pelvic limbs, brachial plexus, or distal part of the median nerve. Most neoplasms had characteristic pseudo-onion bulb patterns on histopathology. Neoplastic perineurial cells, in most cases, expressed laminin and claudin-1, and NF200 consistently highlighted the central axon. While the immunohistochemical (IHC) profile of intraneural perineurioma in veterinary medicine remains incompletely characterized, the available IHC data from all reported cases suggest that a combination of laminin and claudin-1 immunomarkers, along with distinctive histological features, can assist in establishing a definitive diagnosis of intraneural perineurioma.