Blood-brain barrier dysfunction and decreased transcription of tight junction proteins in epileptic dogs.

BACKGROUND: Epilepsy in dogs and humans is associated with blood-brain barrier (BBB) dysfunction (BBBD), which may involve dysfunction of tight junction (TJ) proteins, matrix metalloproteases, and astrocytes. Imaging techniques to assess BBB integrity, to identify potential treatment strategies, have not yet been evaluated in veterinary medicine. HYPOTHESIS: Some dogs with idiopathic epilepsy (IE) will exhibit BBBD. Identifying BBBD may improve antiepileptic treatment in the future. ANIMALS: Twenty-seven dogs with IE and 10 healthy controls. METHODS: Retrospective, prospective cohort study. Blood-brain barrier permeability (BBBP) scores were calculated for the whole brain and piriform lobe of all dogs by using dynamic contrast enhancement (DCE) magnetic resonance imaging (MRI) and subtraction enhancement analysis (SEA). Matrix metalloproteinase-9 (MMP9) activity in serum and cerebrospinal fluid (CSF) was measured and its expression in the piriform lobe was examined using immunofluorescent staining. Gene expression of TJ proteins and astrocytic transporters was analyzed in the piriform lobe. RESULTS: The DCE-MRI analysis of the piriform lobe identified higher BBBP score in the IE group when compared with controls (34.5% vs 26.5%; P = .02). Activity and expression of MMP9 were increased in the serum, CSF, and piriform lobe of IE dogs as compared with controls. Gene expression of Kir4.1 and claudin-5 in the piriform lobe of IE dogs was significantly lower than in control dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Our findings demonstrate BBBD in dogs with IE and were supported by increased MMP9 activity and downregulation of astrocytic potassium channels and some TJ proteins. Blood brain barrier dysfunction may be a novel antiepileptic therapy target.

Evaluation of a treatment protocol in dogs with intraspinal spirocercosis.

OBJECTIVE: To evaluate the efficiency and safety of a doramectin-based treatment protocol in dogs affected by intraspinal spirocercosis (Spirocerca lupi). ANIMALS: Client-owned dogs that were admitted to a veterinary hospital during 2021 to 2022 with acute onset of neurological signs and diagnosed with intraspinal spirocercosis. All dogs underwent complete neurological evaluation, CSF analysis, PCR confirmation of CNS S lupi infection, and follow-up evaluation of at least 6 months. PROCEDURES: Upon diagnosis, dogs were treated with doramectin at a dose of 400 µg/kg, SC, q 24 h for 3 consecutive days, followed by the same dose once a week for 6 weeks. Prednisone was administered at a dose of 1 mg/kg, PO, q 24 h and tapered every 3 days. Antimicrobial clindamycin was administered at a dose of 12.5 mg/kg, PO, q 12 h for 7 days to reduce the risk of secondary spinal cord infection. Short- and long-term outcomes (1 week to 56 months) were recorded. RESULTS: 8 dogs fulfilled the inclusion criteria, 7 of which presented with neurological deficits and 1 with cervical pain. Initiation of treatment was associated with stopping the deterioration in 7 of 8 dogs. Seven dogs improved and 6 recovered ambulation. One dog was euthanized due to lack of improvement. Six of the recovered dogs were still ataxic on the last follow-up examination at 6 to 56 months. No adverse effects of the drug were noted. CLINICAL RELEVANCE: Frequent administration of doramectin was found to be safe and effective in preventing neurological deterioration in dogs with intraspinal spirocercosis.

Spinal cord protothecosis causing paraparesis in a dog.

Protothecosis, an infectious disease caused by the green algae Prototheca zopfii and P. wickerhamii, occurs sporadically in domestic animals and humans. Diagnosis of CNS protothecosis is based on neurologic signs that indicate multifocal nervous system lesions and that follow a period of chronic diarrhea and weight loss, cytologic observation of algae in fecal culture or histopathology, and detection of the agent by PCR assay of infected tissues. Here, we report a case of a paraparetic dog with CNS protothecosis that was diagnosed definitively antemortem using CSF cytology, PCR, and DNA sequencing. A 4-y-old mixed-breed dog developed progressive paraparesis that followed weight loss and diarrhea. CSF analysis revealed marked eosinophilic pleocytosis. Prototheca organisms were detected by microscopic examination of the CSF, and speciated as P. zopfii by CSF PCR and DNA sequencing. Other possible causes of paraparesis were ruled out using computed tomography, serology, and CSF PCR. The dog's condition deteriorated despite treatment, developing forebrain and central vestibular system clinical signs, and it was euthanized at the owner's request. Postmortem examination was declined. Our findings indicate that when CNS protothecosis is suspected, antemortem diagnosis can be made using CSF analysis and a PCR assay.

Detection of blood-brain barrier dysfunction using advanced imaging methods to predict seizures in dogs with meningoencephalitis of unknown origin.

BACKGROUND: The blood-brain barrier (BBB), which separates the intravascular and neuropil compartments, characterizes the vascular bed of the brain and is essential for its proper function. Recent advances in imaging techniques have driven the development of methods for quantitative assessment of BBB permeability. HYPOTHESIS/OBJECTIVES: Permeability of the BBB can be assessed quantitatively in dogs with meningoencephalitis of unknown origin (MUO) and its status is associated with the occurrence of seizures. ANIMALS: Forty dogs with MUO and 12 dogs without MUO. METHODS: Retrospective, prospective cohort study. Both dynamic contrast enhancement (DCE) and subtraction enhancement analysis (SEA) methods were used to evaluate of BBB permeability in affected (DCE, n = 8; SEA, n = 32) and control dogs (DCE, n = 6; SEA, n = 6). Association between BBB dysfunction (BBBD) score and clinical characteristics was examined. In brain regions where BBBD was identified by DCE or SEA magnetic resonance imaging (MRI) analysis, immunofluorescent staining for albumin, glial fibrillary acidic protein, ionized calcium binding adaptor molecule, and phosphorylated mothers against decapentaplegic homolog 2 were performed to detect albumin extravasation, reactive astrocytes, activated microglia, and transforming growth factor beta signaling, respectively. RESULTS: Dogs with BBBD had significantly higher seizure prevalence (72% vs 19%; P = .01) when compared to MUO dogs with no BBBD. The addition of SEA to routine MRI evaluation increased the identification rate of brain pathology in dogs with MUO from 50% to 72%. CONCLUSIONS AND CLINICAL IMPORTANCE: Imaging-based assessment of BBB integrity has the potential to predict risk of seizures in dogs with MUO.

Telmisartan as an add-on treatment for dogs with refractory idiopathic epilepsy: a nonrandomized, uncontrolled, open-label clinical trial.

OBJECTIVE: To evaluate the effect on seizure frequency of add-on telmisartan treatment in dogs with refractory idiopathic epilepsy. ANIMALS: 11 client-owned dogs with idiopathic epilepsy and ≥ 2 generalized seizures/mon that were currently being treated with ≥ 2 antiepileptic drugs. PROCEDURES: Telmisartan was administered at a dosage of 0.25 to 1 mg/kg, PO, every 12 hours for 4 to 16 months. Seizure frequencies before and during telmisartan treatment were recorded. RESULTS: 10 dogs completed the 4-month treatment protocol. One dog was excluded owing to a transient increase in serum creatinine concentration; no adverse effects of telmisartan were observed in the remaining 10 dogs. A reduction in seizure frequency greater than an estimated expected placebo effect of 30% was evident in 7 of the 10 dogs. Long-term (12 to 16 months) follow-up information was available for 6 dogs, of which 4 had a further reduction in seizure frequency. Differences in seizure frequency were not statistically significant. No significant difference was found in serum phenobarbital concentration throughout the treatment period in the 7 dogs that were tested. CLINICAL RELEVANCE: Telmisartan has the potential to reduce seizure frequency when administered as an add-on antiepileptic drug in dogs with refractory idiopathic epilepsy. A randomized, double-blind, placebo-controlled trial is needed to determine the true efficacy of telmisartan. On the basis of our results, a sample size of 54 dogs with refractory idiopathic epilepsy would be needed.

CT findings and the prognostic value of the Koret CT score in cats with traumatic brain injury.

OBJECTIVES: The aims of this study were to evaluate associations between abnormal head CT findings and outcome, and to examine the prognostic value of the Koret CT score (KCTS) in cats sustaining acute traumatic brain injury (TBI). METHODS: The medical records of cats hospitalised with TBI that underwent head CT scans within 72 h of admission were retrospectively reviewed. CT scans were evaluated independently by a radiologist and a neurologist who were blinded to the outcome. A KCTS and modified Glasgow Coma Scale (MGCS) were assigned to each cat and the association between abnormal CT findings, KCTS, MGCS and outcome were analysed. RESULTS: Fourteen cats were included in the study: nine (64.2%) survivors and five (35.7%) non-survivors. Of the nine cats that were discharged, one was a short-term survivor (10 days) and eight (57.1%) were long-term survivors (⩾6 months). Abnormal CT findings included lateral ventricle asymmetry/midline shift (42.8%), intracranial haemorrhage (35.7%), caudotentorial lesions (14.2%) and cranial vault fractures (14.2%), all of which were depressed. Intracranial haemorrhage was found to be significantly and negatively associated with short-term (P = 0.005) and long-term (P = 0.023) survival. KCTS was significantly associated with short-term survival (P = 0.002) and long-term survival (P = 0.004). A KCTS cut-off value of 2 yielded a 100% sensitivity and 100% specificity for short-term survival and 100% sensitivity and 80% specificity for long-term survival. A MGCS cut-off value of ⩾13 was associated with a 100% sensitivity and 100% specificity for short-term survival, and with a 100% sensitivity and 80% specificity for long-term survival. CONCLUSIONS AND RELEVANCE: KCTS, performed up to 72 h from injury, can be used as an additional diagnostic tool for the prediction of survival in cats with TBI.

Paroxysmal slow cortical activity in Alzheimer's disease and epilepsy is associated with blood-brain barrier dysfunction.

A growing body of evidence shows that epileptic activity is frequent but often undiagnosed in patients with Alzheimer's disease (AD) and has major therapeutic implications. Here, we analyzed electroencephalogram (EEG) data from patients with AD and found an EEG signature of transient slowing of the cortical network that we termed paroxysmal slow wave events (PSWEs). The occurrence per minute of the PSWEs was correlated with level of cognitive impairment. Interictal (between seizures) PSWEs were also found in patients with epilepsy, localized to cortical regions displaying blood-brain barrier (BBB) dysfunction, and in three rodent models with BBB pathology: aged mice, young 5x familial AD model, and status epilepticus-induced epilepsy in young rats. To investigate the potential causative role of BBB dysfunction in network modifications underlying PSWEs, we infused the serum protein albumin directly into the cerebral ventricles of naïve young rats. Infusion of albumin, but not artificial cerebrospinal fluid control, resulted in high incidence of PSWEs. Our results identify PSWEs as an EEG manifestation of nonconvulsive seizures in patients with AD and suggest BBB pathology as an underlying mechanism and as a promising therapeutic target.

Blood-brain barrier dysfunction in canine epileptic seizures detected by dynamic contrast-enhanced magnetic resonance imaging.

OBJECTIVE: Dogs with spontaneous or acquired epilepsy exhibit resemblance in etiology and disease course to humans, potentially offering a translational model of the human disease. Blood-brain barrier dysfunction (BBBD) has been shown to partake in epileptogenesis in experimental models of epilepsy. To test the hypothesis that BBBD can be detected in dogs with naturally occurring seizures, we developed a linear dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) analysis algorithm that was validated in clinical cases of seizing dogs and experimental epileptic rats. METHODS: Forty-six dogs with naturally occurring seizures of different etiologies and 12 induced epilepsy rats were imaged using DCE-MRI. Six healthy dogs and 12 naive rats served as control. DCE-MRI was analyzed by linear-dynamic method. BBBD scores were calculated in whole brain and in specific brain regions. Immunofluorescence analysis for transforming growth factor beta (TGF-ß) pathway proteins was performed on the piriform cortex of epileptic dogs. RESULTS: We found BBBD in 37% of dogs with seizures. A significantly higher cerebrospinal fluid to serum albumin ratio was found in dogs with BBBD relative to dogs with intact blood-brain barrier (BBB). A significant difference was found between epileptic and control rats when BBBD scores were calculated for the piriform cortex at 48 hours and 1 month after status epilepticus. Mean BBBD score of the piriform lobe in idiopathic epilepsy (IE) dogs was significantly higher compared to control. Immunohistochemistry results suggested active TGF-ß signaling and neuroinflammation in the piriform cortex of dogs with IE, showing increased levels of serum albumin colocalized with glial acidic fibrillary protein and pSMAD2 in an area where BBBD had been detected by linear DCE-MRI. SIGNIFICANCE: Detection of BBBD in dogs with naturally occurring epilepsy provides the ground for future studies for evaluation of novel treatment targeting the disrupted BBB. The involvement of the piriform lobe seen using our linear DCE-MRI protocol and algorithm emphasizes the possibility of using dogs as a translational model for the human disease.

Clinical characteristics of Spirocerca lupi migration in the spinal cord.

Spirocerca lupi is a nematode infecting dogs mostly in tropical and subtropical areas. Although its typical target is the esophageal wall, aberrant migration is not uncommon, including migration of unknown incidence into the spinal cord. While successful treatment of intraspinal S. lupi (ISSL) infection depends on early diagnosis, tools for definitive ante-mortem diagnosis are unavailable. We therefore aimed at characterizing clinical signs and clinical pathology findings of ISSL in dogs. For that, we analyzed medical records of dogs hospitalized in 2005-2016 presenting with neurological signs consistent with ISSL, which were diagnosed definitively post-mortem. Retrieved information included signalment, medical history, chief complaint, physical and neurological evaluation, neuroanatomical localization at presentation, clinical pathology, imaging findings, treatment, outcome and post-mortem findings. Ten midsize to large breed dogs were included, 7 of which had received prophylactic treatment. In all 10 dogs, onset was acute and neurological deterioration until presentation (2 h-6 d) was fast. Neurological examination localized the lesions within the spinal cord and paresis or paralysis was asymmetric in all dogs. Spinal pain was documented in 9/10 dogs. Cerebrospinal fluid (CSF) analysis was abnormal in all dogs and was characterized by pleocytosis in 8/10, whereas cytology revealed the presence of eosinophils in all dogs. Advanced imaging excluded spinal cord compression in all dogs tested. Post-mortem examination detected spinal cord migration tract in all cases. Nematodes were found in the spinal cord parenchyma (8/10) or adjacent to it (2/10) in all dogs. A larva was found in the subarachnoid space of one dog and an adult nematode in the thoracic intervertebral artery of another. Esophageal nodules were found in 5/10 dogs. These findings suggest that the combination of sudden onset of acute asymmetric paresis accompanied by pain, presence of eosinophils in the CSF and lack of compressive lesion may serve as sufficient evidence for tentative diagnosis of ISSL in endemic areas.

Characteristics of and risk factors for intervertebral disk extrusions in Pekingese.

OBJECTIVE To characterize and identify risk factors for intervertebral disk extrusion (IVDE) in Pekingese. DESIGN Retrospective case-control study. ANIMALS 426 Pekingese (81 with confirmed IVDE and 345 without IVDE) admitted to a veterinary teaching hospital from 2005 through 2015. PROCEDURES Medical records were reviewed and data were extracted regarding age, sex, body weight, body condition score, coat color, chief reason for initial evaluation, body system involved, and diagnosis. Survey radiographs of the vertebral column were examined. Data were compared between the confirmed IVDE and non-IVDE groups. RESULTS Confirmed IVDE was uncommon in dogs < 2 years of age (2/81 [2%]). The extrusion was primarily located in the thoracolumbar (n = 57 [70%]) and cervical (22 [27%]) regions; the most common sites were T12-13 and C6-7. The number of radiographically visible calcified disks was significantly greater in the confirmed IVDE versus non-IVDE group, and the presence of calcified disks in the T10-L4 region was associated with increased odds of IVDE (OR, 21.2). Black coat color was significantly more prevalent in the confirmed IVDE versus non-IVDE group and was associated with increased odds of developing IVDE (OR, 1.6). Mean body weight and the proportion of spayed female dogs were significantly greater in the confirmed IVDE versus non-IVDE group. CONCLUSIONS AND CLINICAL RELEVANCE Several risk factors for confirmed IVDE in Pekingese were identified that could be useful for counseling clients about the disease or, with additional research, designing selective breeding programs to reduce the prevalence of IVDE in the breed.

Computed tomographic findings in dogs with head trauma and development of a novel prognostic computed tomography-based scoring system.

OBJECTIVE To characterize CT findings and outcomes in dogs with head trauma and design a prognostic scale. ANIMALS 27 dogs admitted to the Koret School Veterinary Teaching Hospital within 72 hours after traumatic head injury that underwent CT imaging of the head. PROCEDURES Data were extracted from medical records regarding dog signalment, history, physical and neurologic examination findings, and modified Glasgow coma scale scores. All CT images were retrospectively evaluated by a radiologist unaware of dog status. Short-term (10 days after trauma) and long-term (≥ 6 months after trauma) outcomes were determined, and CT findings and other variables were analyzed for associations with outcome. A prognostic CT-based scale was developed on the basis of the results. RESULTS Cranial vault fractures, parenchymal abnormalities, or both were identified via CT in 24 of 27 (89%) dogs. Three (11%) dogs had only facial bone fractures. Intracranial hemorrhage was identified in 16 (59%) dogs, cranial vault fractures in 15 (56%), midline shift in 14 (52%), lateral ventricle asymmetry in 12 (44%), and hydrocephalus in 7 (26%). Hemorrhage and ventricular asymmetry were significantly and negatively associated with short- and long-term survival, respectively. The developed 7-point prognostic scale included points for hemorrhage, midline shift or lateral ventricle asymmetry, cranial vault fracture, and depressed fracture (1 point each) and infratentorial lesion (3 points). CONCLUSIONS AND CLINICAL RELEVANCE The findings reported here may assist in determining prognoses for other dogs with head trauma. The developed scale may be useful for outcome assessment of dogs with head trauma; however, it must be validated before clinical application.

DORSAL LAMINECTOMY TO RELIEVE SPINAL CORD COMPRESSION IN A CAPTIVE SYRIAN BEAR (URSUS ARCTOS SYRIACUS).

A 19-yr-old captive male Syrian bear ( Ursus arctos syriacus) presented with a right hind limb lameness that progressed to nonambulatory paraparesis over the course of 2 wk. When night enclosure confinement and a short course of glucocorticoids and antibiotics did not lead to improvement, radiographs were performed, followed by cerebrospinal fluid analysis and myelography, revealing a dynamic spinal cord compression at the level of T2-T3. Dorsal laminectomy of both T2 and T3 was performed to allow decompression. The bear recovered uneventfully with first sign of neurological improvement apparent at 10 days postoperatively. Following 6 mo of rehabilitation the bear was walking and using his hind limbs normally.

Retrospective evaluation of combined mycophenolate mofetil and prednisone treatment for meningoencephalomyelitis of unknown etiology in dogs: 25 cases (2005-2011).

OBJECTIVE: To evaluate the use of a combined protocol of prednisone and mycophenolate mofetil (MMF) for the treatment of meningoencephalomyelitis of unknown etiology (MUE) and to describe response, adverse effects, and outcome. DESIGN: Retrospective study (2005-2011). SETTING: University teaching hospital. ANIMALS: Twenty-five client-owned dogs with clinical signs, neuroimaging, and cerebrospinal abnormalities consistent with MUE. Five dogs whose MMF treatment was discontinued after 7-14 days due to gastrointestinal clinical signs were evaluated only for adverse effects. INTERVENTIONS: Dogs were initially treated with prednisone 2 mg/kg PO every 12 hours and with MMF 20 mg/kg PO or IV every 12 hours. Prednisone was tapered after 4 days to 1 mg/kg every 12 hours for 14 days, then to every 24 hours for 30 days, and again reduced by half every 2-4 months thereafter. When prednisone was tapered completely or to 0.5 mg/kg every 24-48 hours without clinical relapse, MMF was tapered in a similar manner. MEASUREMENTS AND MAIN RESULTS: Partial or complete clinical response was achieved in 95% (19/20) of the dogs. Median survival time by the end of the study was 250 days (range 6 to >1,679) with 40% (8/20) of the dogs still alive (336-1,679 days after diagnosis). All Pug dogs (4/20) included in the study died with a median survival time of 14 days. Adverse effects attributed to MMF, which included hemorrhagic diarrhea within the first 2 weeks of treatment, were recorded in 20% (5/25) of the dogs. CONCLUSIONS: MMF can be used as an adjunctive treatment for dogs with MUE. This protocol enables reduction of prednisone treatment or, in some cases, its complete withdrawal. The possibility of intravenous administration is advantageous in cases with severe neurological abnormalities and mentation changes, often seen in MUE. Attention is warranted for gastrointestinal adverse effects, especially in the first 2 weeks of treatment.

Polioencephalomyelopathy in a mixed breed dog resembling Leigh's disease.

A 14-month-old mixed-breed dog was presented with acute onset of exercise intolerance that quickly progressed to quadriparesis. Gross and microscopic autopsy findings indicated a type of degenerative polioencephalomyelopathy resembling subacute necrotizing encephalomyelopathy in dogs or Leigh's disease in humans. This syndrome has previously been reported only in purebred dogs.

Polioencéphalomyélopathie chez un chien de race croisée ressemblant au syndrome de Leigh. Un chien de race croisée âgé de 14 mois a été présenté avec l'apparition aiguë d'intolérance à l'exercice qui a rapidement progressé à la quadriparésie. Suite à la nécropsie, les constatations macroscopiques et microscopique ont indiqué un type de polioencéphalomyélopathie dégénérative ressemblant à l'encéphalomyélopathie nécrosante subaiguë chez les chiens ou au syndrome de Leigh chez les humains. Ce syndrome avait été signalé précédemment seulement chez les chiens de race pure.(Traduit par Isabelle Vallières).

Reversible paralysis and loss of deep pain sensation after topical intrathecal morphine administration following durotomy.

OBJECTIVE: To report 2 dogs that developed temporary pelvic limb paralysis with loss of deep pain sensation after topical intrathecal morphine administration during spinal surgery. STUDY DESIGN: Clinical report. ANIMALS: Dogs (n = 2). METHODS: A 5-year-old castrated male French Bulldog with a subarachnoid diverticulum at T9-T10 and a 9.5-year-old castrated male Belgian Shepherd dog with a herniated disc at T12-T13 and intradural component, had Gelfoam soaked with morphine placed over the dura mater defect. RESULTS: Pelvic limb paralysis and loss of deep pain sensation was noticed immediately after recovery from anesthesia. After intravenous naloxone administration, both dogs immediately regained ambulation and normal pain sensation; however the effect was temporary lasting only a few hours. Permanent resolution of clinical signs occurred 24 hours after surgery. CONCLUSIONS: Topical intrathecal morphine administration resulted in temporary pelvic limb paralysis and loss of deep pain sensation. This route of administration should be used cautiously until further determination of the efficacy and adverse effects associated with topical intrathecal morphine administration.

Taenia multiceps brain cyst removal in two wild Nubian ibex (Capra nubianas).

Two wild adult Nubian ibex (Capra nubiana) were captured and admitted to the Hebrew University Veterinary Teaching Hospital with various neurologic signs, including alerted mentation, head tilt, and pathologic nystagmus. The lesion in the central nervous system was localized to the forebrain in one ibex and to the cerebellum of the other. Both ibex's were diagnosed with brain cyst using computed tomography (CT). Craniectomy was performed to remove the cysts, and both animals returned to their natural environment after a rehabilitation period. Parasitologic examination revealed cysts of Taenia multiceps coenurus. This is the first report to describe the neurologic signs, CT findings, surgical procedure, and follow-up postsurgery information in wild Capra nubiana.

Comparative skull analysis suggests species-specific captivity-related malformation in lions (Panthera leo).

Lion (Panthera leo) populations have dramatically decreased worldwide with a surviving population estimated at 32,000 across the African savannah. Lions have been kept in captivity for centuries and, although they reproduce well, high rates of stillbirths as well as morbidity and mortality of neonate and young lions are reported. Many of these cases are associated with bone malformations, including foramen magnum (FM) stenosis and thickened tentorium cerebelli. The precise causes of these malformations and whether they are unique to captive lions remain unclear. To test whether captivity is associated with FM stenosis, we evaluated 575 lion skulls of wild (N = 512) and captive (N = 63) origin. Tiger skulls (N = 276; 56 captive, 220 wild) were measured for comparison. While no differences were found between males and females or between subadults and adults in FM height (FMH), FMH of captive lions (17.36±3.20 mm) was significantly smaller and with greater variability when compared to that in wild lions (19.77±2.11 mm). There was no difference between wild (18.47±1.26 mm) and captive (18.56±1.64 mm) tigers in FMH. Birth origin (wild vs. captive) as a factor for FMH remained significant in lions even after controlling for age and sex. Whereas only 20/473 wild lions (4.2%) had FMH equal to or smaller than the 5th percentile of the wild population (16.60 mm), this was evident in 40.4% (23/57) of captive lion skulls. Similar comparison for tigers found no differences between the captive and wild populations. Lions with FMH equal to or smaller than the 5th percentile had wider skulls with smaller cranial volume. Cranial volume remained smaller in both male and female captive lions when controlled for skull size. These findings suggest species- and captivity-related predisposition for the pathology in lions.

Acetylcholinesterase activity in the cerebrospinal fluid of dogs with seizures.

Recent studies in animal models have focused on the role of cholinergic elements, mainly acetylcholinesterase (AChE) and the 'readthrough' acetylcholinesterase isoform (AChE-R), in seizures. A prospective double-masked study was conducted to assess the activity of AChE and AChE-R in cerebrospinal fluid (CSF) of 26 dogs post-seizure, 28 dogs with intervertebral disc disease (IVDD) and 16 healthy dogs. AChE was also measured in the serum in the post-seizure and IVDD groups. The results showed no significant differences in CSF AChE among the three groups. AChE-R was not detected in any dog and AChE in the serum was similar between groups. This preliminary study provides new information on AChE and AChE-R in the CSF and sera of dogs following naturally-occurring seizures.

Needle biopsy for hepatic vitamin A levels in lions (Panthera leo).

Hypovitaminosis A (HA)-related skull malformations resulting in neurologic abnormalities and death have been, and still are, reported in captive lions (Panthera leo) worldwide. Liver vitamin A (VA) concentration is the most reliable indicator of animals' VA status, and its assessment is essential in prevention and treatment of HA in lions. A percutaneous needle liver biopsy using high-performance liquid chromatography ultraviolet retinoid analysis for VA concentration measurement was validated. It was first assessed in vitro using chicken liver. Later, the safety and feasibility of ultrasound-guided percutaneous needle liver biopsy was assessed in living lions. Hepatic VA concentrations in lion liver were measured using the above laboratory method. Mean chicken hepatic VA concentration in needle biopsy (NB) and wedge biopsy (WB) of the same liver lobes were 108.66 and 60.89 microg/g wet tissue, respectively, and were significantly (P = 0.03) correlated (r = 0.74). The calculated linear regression for predicting VA concentration in WB using NB VA for chicken liver was 25.194 + 0.3234x NB (microg/g). Four ultrasound-guided percutaneous needle liver biopsies were obtained from each of the four lions under general anesthesia. Mean hepatic VA concentration was 8.25 microg/g wet tissue (range 1.43-25.29 microg/g). Mean serum VA concentration, measured in these four lions was 1,011.1 nmol/L with a standard deviation of 337.91 nmol/L (range 590.26-1,077.2 nmol/L). The lions recovered uneventfully, and no complications were observed during a 4-yr follow-up period. In conclusion, the percutaneous needle liver biopsy technique is a reliable, practical, safe tool for obtaining liver tissue samples antemortem for assessment of the VA status in lions and can be used in future studies.

Spontaneous intradural disc herniation with focal distension of the subarachnoid space in a dog.

Myelo-computed tomography of a paraparetic 14-year-old dog revealed subarachnoid distension with an intradural filling defect above the T13-L1 disc space. T12-L1 hemilaminectomy followed by durotomy allowed removal of a large piece of degenerated disc material that compressed the spinal parenchyma. Full return to function was achieved 10 days post-surgery. The distension was likely secondary to the intradural herniation, and is a rare and distinct finding.

Hernie discale intra-durale spontanée avec distension focale de l'espace sous-arachnoïdien chez un chien. Une myélo-tomographie par ordinateur d'un chien paraparétique âgé de 14 ans a révélé une distension sous-arachnoïdienne avec un défaut de remplissage intradural au-dessus de l'espace du disque T13­L1. Une hémilaminectomie de T12­L1 suivie d'une durotomie ont permis l'enlèvement d'un grand morceau de matériel dégénéré du disque qui comprimait le parenchyme rachidien. Un retour complet à la fonction a été obtenu 10 jours après la chirurgie. La distension était probablement secondaire à l'hernie intradurale et représente une constatation rare et distincte.(Traduit par Isabelle Vallières).