Iris Van Soens

Myokymia and neuromyotonia in 37 Jack Russell terriers

The clinical and clinicopathological characteristics, treatment and outcome of vermicular muscle contractions (myokymia) and generalized muscle stiffness (neuromyotonia) in 37 Jack Russell terriers were evaluated retrospectively. Thirty dogs were affected by both disorders, whereas seven were presented with myokymia and never developed neuromyotonia. Clinical signs started at the mean age of 8 months. Except for signs of myokymia and neuromyotonia, clinical and neurological examination was normal in all dogs. Thirty dogs demonstrated typical signs of hereditary ataxia. Changes in serum chemistry included increased creatine kinase, aspartate aminotransferase and alanine aminotransferase concentrations. Electromyographic abnormalities, especially in muscles showing macroscopically visible myokymia, consisted of semirhythmic bursts of doublet, triplet, or multiplet discharges of a single motor unit. The amplitudes varied between 80 μV and 1 mV and occurred with an interburst frequency between 10 and 40 Hz and an intraburst frequency between 150 and 280 Hz. Most dogs were treated with a sodium channel blocker with variable results. Seven dogs died (most likely because of hyperthermia) or were euthanased during a neuromyotonic attack; 15 dogs were euthanased due to worsening of clinical signs, or lack of or no long-lasting effect of medication, and three were euthanased for unknown or unrelated reasons. Nine dogs were lost to follow-up and three were still alive 5-10.5 years after the start of clinical signs. In conclusion, young Jack Russell terriers with myokymia and neuromyotonia should undergo a complete blood and electrophysiological examination. Long-term prognosis is not favourable.

Intraobserver and interobserver agreement for results of low-field magnetic resonance imaging in dogs with and without clinical signs of disk-associated wobbler syndrome.

OBJECTIVE To determine interobserver and intraobserver agreement for results of low-field magnetic resonance imaging (MRI) in dogs with and without disk-associated wobbler syndrome (DAWS). DESIGN Validation study. ANIMALS 21 dogs with and 23 dogs without clinical signs of DAWS. PROCEDURES For each dog, MRI of the cervical vertebral column was performed. The MRI studies were presented in a randomized sequence to 4 board-certified radiologists blinded to clinical status. Observers assessed degree of disk degeneration, disk-associated and dorsal compression, alterations in intraspinal signal intensity (ISI), vertebral body abnormalities, and new bone formation and categorized each study as originating from a clinically affected or clinically normal dog. Interobserver agreement was calculated for 44 initial measurements for each observer. Intraobserver agreement was calculated for 11 replicate measurements for each observer. RESULTS There was good interobserver agreement for ratings of disk degeneration and vertebral body abnormalities and moderate interobserver agreement for ratings of disk-associated compression, dorsal compression, alterations in ISI, new bone formation, and suspected clinical status. There was very good intraobserver agreement for ratings of disk degeneration, disk-associated compression, alterations in ISI, vertebral body abnormalities, and suspected clinical status. There was good intraobserver agreement for ratings of dorsal compression and new bone formation. Two of 21 clinically affected dogs were erroneously categorized as clinically normal, and 4 of 23 clinically normal dogs were erroneously categorized as clinically affected. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that variability exists among observers with regard to results of MRI in dogs with DAWS and that MRI could lead to false-positive and false-negative assessments.

Evolution of clinical signs and predictors of outcome after conservative medical treatment for disk-associated cervical spondylomyelopathy in dogs.

OBJECTIVE To evaluate the evolution of clinical signs and their correlation with results of magnetic resonance imaging (MRI) and transcranial magnetic stimulation (TMS) and to assess potential prognostic variables after conservative medical treatment for disk-associated cervical spondylomyelopathy (DA-CSM) in dogs. DESIGN Prospective cohort study. ANIMALS 21 client-owned dogs with DA-CSM. PROCEDURES After neurologic grading, dogs underwent low-field MRI and TMS with measurement of onset latencies and peak-to-peak amplitudes from the extensor carpi radialis and cranial tibial muscles. Dimensions calculated from MRI images were remaining spinal cord area, spinal cord compression ratio, vertebral occupying ratio, vertebral canal height-to-body height ratio, vertebral canal height-to-body length ratio, and vertebral canal compromise ratio. Intraparenchymal signal intensity changes were graded. Dogs were reevaluated 1, 3, 6, 12, and 24 months after initial diagnosis. RESULTS Outcome was successful in 8 of 21 dogs. Negative outcomes were characterized by rapid progression of clinical signs. All dogs with more severe clinical signs of DA-CSM 1 month after diagnosis had unsuccessful outcomes. Outcome was associated with the remaining spinal cord area and vertebral canal compromise ratio. Prognosis was not associated with severity of clinical signs or results of TMS. There were no significant correlations among clinical signs, MRI findings, and TMS results. CONCLUSIONS AND CLINICAL RELEVANCE Conservative medical treatment of DA-CSM was associated with a guarded prognosis. Selected MRI variables and clinical evolution 1 month after diagnosis can be considered prognostic indicators. The lack of correlation among clinical signs, results of diagnostic imaging, and results of electrophysiologic evaluation in dogs with DA-CSM warrants further investigation.

Transcranial magnetic stimulation in Doberman Pinschers with clinically relevant and clinically irrelevant spinal cord compression on magnetic resonance imaging

OBJECTIVE To evaluate the use of transcranial magnetic stimulation for differentiating between clinically relevant and clinically irrelevant cervical spinal cord compression on magnetic resonance imaging (MRI). DESIGN Validation study. ANIMALS Clinically normal Doberman Pinschers without (n = 11) and with (6) spinal cord compression on MRI and 16 Doberman Pinschers with disk-associated wobbler syndrome (DAWS). PROCEDURES After dogs were sedated, transcranial magnetic motor evoked potentials were recorded from the extensor carpi radialis muscle (ECRM) and cranial tibial muscle (CTM). Onset latencies and peak-to-peak amplitudes were measured. Magnetic resonance imaging was performed to identify spinal cord compression. RESULTS There were significant differences in ECRM and CTM onset latencies between Doberman Pinschers with DAWS and each of the 2 groups of clinically normal dogs, but there were no significant differences in ECRM and CTM onset latencies between the 2 groups of clinically normal dogs. There were significant differences in CTM peak-to-peak amplitudes between Doberman Pinschers with DAWS and each of the 2 groups of clinically normal dogs, but there were no significant differences in ECRM peak-to-peak amplitudes among groups or in CTM peak-to-peak amplitudes between the 2 groups of clinically normal dogs. There was a significant correlation between severity of spinal cord compression and ECRM onset latency, CTM onset latency, and CTM peak-to-peak amplitude. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that transcranial magnetic stimulation may be a useful diagnostic tool to differentiate between clinically relevant and clinically irrelevant spinal cord compression identified on MRI alone.

Surgical Treatment of a Canine Intranasal Meningoencephalocele

OBJECTIVE To report the clinical signs, diagnosis, and surgical treatment of an intranasal meningoencephalocele in a dog. STUDY DESIGN Case report. ANIMAL Female Border collie, 5 months old. METHODS A right intranasal meningoencephalocele was identified by computed tomography and magnetic resonance imaging. RESULTS The lesion was approached by a modified transfrontal craniotomy. Surgical closure of the defect at the level of the cribriform plate and removal of extruded brain tissue resulted in regression of lacrimation and coincided with absence of seizuring. Treatment with phenobarbital was gradually reduced and stopped at 7 months after surgery. At 28 months the dog remained free of seizures. CONCLUSION Meningoencephalocele, although rare, can cause seizures in dogs and can be treated surgically. CLINICAL RELEVANCE A transfrontal craniotomy with excision of the meningoencephalocele and closure of the defect can be an effective treatment for an intranasal meningoencephalocele in dogs.

Effects of sedative and hypnotic drug combinations on transcranial magnetic motor evoked potential, bispectral index and ARX-derived auditory evoked potential index in dogs

Relationships between onset latency and peak-to-peak amplitude of magnetic motor evoked potentials (MMEP) after transcranial magnetic stimulation (TMS), together with the electroencephalographic parameters bispectral analysis index (BIS) and the autoregressive model with exogenous input (ARX)-derived auditory evoked potential index (AAI) were explored during different sedative and hypnotic drug combinations in six dogs. TMS was performed under sedation with acepromazine/methadone or medetomidine and after a single bolus injection of propofol or etomidate. Data for BIS and AAI were continuously collected during the periods of treatment with the hypnotic drugs. Changes in BIS and AAI during both periods were not statistically correlated with changes in onset latencies and peak-to-peak amplitudes of MMEP after TMS. Therefore, both electroencephalographic techniques are of limited use in titrating sedation and anaesthesia during TMS in the dog.

Magnetic stimulation of the radial nerve in dogs and cats with brachial plexus trauma: A report of 53 cases

Brachial plexus trauma is a common clinical entity in small animal practice and prognostic indicators are essential early in the course of the disease. Magnetic stimulation of the radial nerve and consequent recording of the magnetic motor evoked potential (MMEP) was examined in 36 dogs and 17 cats with unilateral brachial plexus trauma. Absence of deep pain perception (DPP), ipsilateral loss of panniculus reflex, partial Horners syndrome and a poor response to MMEP were related to the clinical outcome in 29 of the dogs and 13 of the cats. For all animals, a significant difference was found in MMEP between the normal and the affected limb. Absence of DPP and unilateral loss of the panniculus reflex were indicative of an unsuccessful outcome in dogs. Additionally, the inability to evoke a MMEP was associated with an unsuccessful outcome in all animals. It was concluded that magnetic stimulation of the radial nerve in dogs and cats with brachial plexus trauma may provide an additional diagnostic and prognostic tool.

Assessment of motor pathways by magnetic stimulation in human and veterinary medicine

Magnetic stimulation is a non-invasive and painless technique for studying the motor pathways in medical neurology. A time-varying magnetic field induces an electrical field in conducting objects, such as nervous tissue. The technique can be applied to nerve roots and peripheral nerves or to the motor cortex of the brain in human and veterinary medicine. In this review, the basic principles, applications and risk factors of peripheral nerve and motor cortex stimulation in human and veterinary medicine are discussed.

Idiopathic generalised tremor syndrome in two cats

Two male neutered domestic shorthair cats were evaluated for generalised tremors. On neurological examination both cats showed whole-body tremors, worsening with stress. A mainly cerebellar disorder was suspected. Blood examination, cerebrospinal fluid analysis and electrophysiological examination of both cats and magnetic resonance imaging of the brain in one cat were normal. Idiopathic generalised tremor syndrome (IGTS) was suspected owing to the exclusion of underlying causes and the clinical similarities with the syndrome in dogs. Treatment as recommended for dogs was initiated and resulted in improvement. This report describes the first cases of IGTS in cats.

Short-and-long-term outcome in 63 dogs treated conservatively or surgically for disc associated wobbler syndrome

Adiponectin has been investigated widely due to its association with adiposity and the metabolic syndrome in human beings. Adiponectin circulates as low- (LMW) and high-molecular weight (HMW) multimers and the latter are the more bioactive forms. There are no reports of the relative proportion (distribution) of adiponectin multimers in feline plasma. The aim of this study was to assess the association of dietary nutrient composition, body weight gain, meal feeding, and insulin sensitivity with HMW adiponectin concentration and adiponectin multimer distribution in cats.1 EVALUATION OF FOUR DNA EXTRACTION METHODS FOR THE DETECTION OF TRITRICHOMONAS FOETUS IN FELINE STOOL SPECIMENS BY POLYMERASE CHAIN REACTION. SH Stauffer, AJ Birkenheuer, MG Levy, H Marr, JL Gookin. College of Veterinary Medicine, North Carolina State University, Raleigh, NC. Feces are increasingly recognized as practical samples for molecular diagnosis of infectious disease. Extraction of PCR-quality DNA from feces can be challenging due to co-extraction of PCR inhibitors. Accordingly, we examined the effect of four commercially-available DNA extraction methods on sensitivity of PCR for detection of Tritrichomonas foetus (TF) in naturally-infected and TF-spiked feline stool. Kits evaluated included ExtractMaster Fecal DNA Extraction Kit, Epicentre Biotechnologies (Kit A); QIAamp DNA Stool Mini Kit, Qiagen (Kit B); UltraClean Fecal DNA Kit, MoBio (Kit C); and ZR Fecal DNA Kit, Zymo Research (Kit D). In accordance with manufacturer instructions, DNA was extracted from 180mg (A,B), 50mg (C), 100 & 150mg (D) aliquots of feline feces to which was added 20ml volumes containing 0–10,000 cultured feline TF. Each kit was also used to extract DNA from the feces of each of 10 naturally infected and 10 uninfected cats. DNA was eluted in 300ml (A), 200ml (B), 50ml (C), or 100ml (D) of respective elution buffer. Endogenous PCR inhibitors in extracted DNA was examined by PCR amplification of an 876 bp gene fragment of bacterial 16S rRNA. DNA was then tested by single tube nested PCR for amplification of partial ITS1, 5.8S and ITS2 rRNA genes of TF. Kit D provided the most sensitive detection of TF DNA as expressed by both organisms per DNA extraction and organisms per PCR reaction. To account for differences in DNA concentrations between kits (i.e. fecal sample size and elution volumes), the limit of detection for each kit as expressed by the number of TF per PCR reaction was as follows: Kit B 5 250, Kit A 5 167, Kit C 5 100, Kit D (150mg fecal sample) 5 5, and Kit D (100mg fecal sample) 5 0.5. PCR performed on DNA extracted from cultured TF (no feces) or TF-spiked feces (100mg) using Kit D was positive with as few as 10 TF per extraction. Further, DNA extraction using Kit D could be completed in the shortest time of all kits tested. These studies identify the ZR Fecal DNA Kit as superior to the other kits tested for extraction of PCR-qualityDNA from feline feces. ABSTRACT #2 INVESTIGATION OF ENTEROBACTER CLOACAE INFECTIONS AT A SMALL ANIMAL VETERINARY TEACHING HOSPITAL. JS Weese. University of Guelph, Guelph, Ontario.2 INVESTIGATION OF ENTEROBACTER CLOACAE INFECTIONS AT A SMALL ANIMAL VETERINARY TEACHING HOSPITAL. JS Weese. University of Guelph, Guelph, Ontario. A wide range of pathogens can cause hospital-associated (HA) infections in small animal hospitals. Among these is Enterobacter cloacae, which is one of the most clinically relevant Enterobacter spp and a common cause of HA infection in humans. Recently, multidrug resistance has become a concern, particularly with emergence of extended-spectrum beta-lactamase and extended spectrum cephalosporinase producing strains. An infection control investigation was initiated at the Ontario Veterinary College Teaching Hospital (OVCTH) in the fall of 2007 in response to anecdotal concerns about Enterobacter cloacae infections in hospitalized animals. Enterobacter cloacae was isolated from 45/36719 animals from January 1, 2005 to October 31, 2007, for an overall incidence of 1.2/ 1000 admissions. The monthly incidence rate ranged from 0 to 4.3/ 1000 admissions. Twenty-one (47%) cases were classified as community-associated, while 17 (38%) were hospital associated. Seven (15%) were community-onset but hospital associated, with three of these associated with other veterinary hospitals. There was no increase in the incidence of overall or hospital-associated infections during the study period. The urinary tract was the most common site of infection (n511, 24%). Wound infections (excluding surgical site infections) accounted for 8 (18%) of infections, with superficial and deep surgical site infections accounting for 7 (16%) and organ/space surgical site infections accounting for another 2 cases. Urinary tract infections were most common among animals with CA infection, accounting for 8/21 (38%) cases with wound infections accounting for 4 (19%) cases. Of the 24 cases associated with the OVCTH, 17 (71%) had surgery, 15 (63%) were hospitalized in the intensive care unit, 10 (42%) had indwelling urinary catheters placed, and 20 (83%) had received antimicrobials prior to onset of infection. Risk factors for E. cloacae infection could not be determined because a noninfected control group was not evaluated. Surgical site infections accounted for 9 (38%) HA cases. Overall, only 2/11 (18%) urinary tract infections were associated with prior placement of a urinary catheter. Nine (20%) animals died or were euthanized and E. cloacae was implicated as a causative or contributing factor in 5 (56%) of those cases. Two main antimicrobial phenotype patterns were identified. One (n525) was characterized by susceptibility to fluoroquinolones, tetracycline, and trimethoprim with variable susceptibility to cefoxitin while the other (n514) was characterized by resistance to these antimicrobials. Prior administration of antimicrobials was associated with presence of the more resistant phenotype (P50.044) but there was no association between this phenotype and origin of infection (P50.74) and no increase in the prevalence of this phenotype from 2005 to 2007 (P50.97). Infections with this phenotype were not associated with nonsurvival (P50.74). There was no evidence of a, HA outbreak or increase in prevalence, yet identification of multidrug resistant E. cloacae in both CA and HA infections is concerning and requires ongoing surveillance. ABSTRACT #3 STAPHYLOCOCCUS PSEUDINTERMEDIUS: A NEWLY RECOGNIZED PATHOGEN IN DOGS AND CATS. MC Faires, D Slavic, JS Weese. Ontario Veterinary College, Animal Health Laboratory, University of Guelph, Guelph, Ontario.3 STAPHYLOCOCCUS PSEUDINTERMEDIUS: A NEWLY RECOGNIZED PATHOGEN IN DOGS AND CATS. MC Faires, D Slavic, JS Weese. Ontario Veterinary College, Animal Health Laboratory, University of Guelph, Guelph, Ontario. Staphylococcus intermedius has typically been regarded as the predominant pathogenic Staphylococcus spp in dogs and cats, and a leading cause of skin and soft tissue infections. In 2005, a novel Staphylococcus species, Staphylococcus pseudintermedius, was identified. This organism is closely related to, but distinct from, S. intermedius. Gene-sequence based methods are required to differentiate these two species; however, these techniques are rarely performed in clinical laboratories, and as a result the prevalence and characteristics of S. pseudintermedius are poorly understood. Recent evidence suggests that S. pseudintermedius may actually be the predominant Staphylococcus spp in dogs and cats but misidentified as S. intermedius by diagnostic laboratories. The objective of this study was to use sequence based methods to identify putative S. intermedius isolates from dogs and cats and to evaluate antimicrobial resistance and virulence factors among S. pseudintermedius isolates. Isolates from dogs and cats identified as S. intermedius by conventional laboratory methods were obtained from the University of Guelph Animal Health Laboratory. Isolates were collected in a serial manner without selection. DNA was extracted, sequencing of the sodA gene was performed, and isolates were identified via sequence alignment with reference staphylococcal strains through GenBank (www.ncbi.nlm.nih.gov/blast/BLAST.cgi). Antimicrobial susceptibility testing was performed and PCR was used to identify various virulence factors and antimicrobial genes. A total of 25 isolates were obtained from 21 dogs and 2 cats. Medical records were not available for 2 of the isolates. 25/25 (100%) were identified as S. pseudintermedius Severity of infection ranged from superficial dermatitis to rapidly fatal necrotizing fasciitis with the majority of isolates from otitis externa 9/23 (39.1%) and urinary tract infections 6/23 (26.1%). Antimicrobial susceptibility was as follows: amoxicillin/clavulanate 23/23 (100%), ampicillin 7/ 23 (30.4%), cephalothin 23/23 (100%), clindamycin 18/23 (78.3%), gentamicin 23/23 (100%), tetracycline 18/23 (78.3%), and trimethoprim/sulfa 19/23 (82.6%). Not all antimicrobials were tested for all isolates, based on laboratory protocols regarding antimicrobial panel and site of infection. Inducible resistance to clindamycin was detected by D-test in 1 isolate reported as clindamycin-susceptible (5.6%). Detection of virulence factors and antimicrobial resistance genes is ongoing. This study identified S. pseudintermedius as an important pathogen in dogs and cats, and suggests that S. intermedius may not be a major concern in these species. Further studies are required to evaluate clinically relevant virulence factors to assist in understanding the pathogenesis of disease caused by S. pseudintermedius. 70