Tim Bosmans

Accuracy of pressure plate kinetic asymmetry indices and their correlation with visual gait assessment scores in lame and nonlame dogs

OBJECTIVE To determine the accuracy of pressure plate kinetic asymmetry indices (ASIs) for diagnosis of unilateral hind limb lameness in dogs and their correlation with visual gait assessment (VGA) scores. ANIMALS 9 healthy dogs and 16 dogs with previously diagnosed unilateral rupture of the cranial cruciate ligament and concurrent unilateral hind limb lameness. PROCEDURES Dogs were walked over a pressure plate to determine paw contact area (PCA), peak vertical pressure (PVP), peak vertical force (PVF), and vertical impulse (VI) of both hind limbs. An ASI was calculated for each gait variable. Simultaneously, gait was assessed visually and scored by use of a numeric rating scale (0 to 10). The ASI of each variable was tested for its usefulness in discrimination between lame and nonlame dogs and for correlation with VGA scores. RESULTS Sensitivity and specificity of ASIs to discriminate between lame and nonlame dogs were excellent for PVF, VI, and PCA; these values were substantially lower for ASI of PVP. Cutoff values to discriminate between lame and nonlame dogs were determined by use of ASIs for PVF, VI, and PCA; however, this could not be done for ASI of PVP. Correlations between ASIs of PVF, VI, and PCA and VGA scores were higher than correlation between the ASIs of PVP and VGA scores. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that ASIs of PVF and VI determined via analysis of pressure plate measurements were reliable indicators of clinical lameness in dogs, but the ASI of PVP was not. The ASI of PCA is an interesting new variable for assessment of limb loading symmetry.

Species comparison of enantioselective oral bioavailability and pharmacokinetics of ketoprofen.

As a part of ongoing research to further elucidate frequent and species-specific causes of differences in oral bioavailability, a 3mg/kg dose of racemic ketoprofen, a high permeability/low solubility compound in the human biopharmaceutics classification system, was administered intravenously and orally to different species. Due to possible enantioselective disposition kinetics and inversion, enantiomers were quantitated separately using a stereospecific HPLC assay. The absolute bioavailability of R(-) and S(+) ketoprofen in chickens, turkeys, dogs and pigs was 31.5% and 52.6%, 42.6% and 32.5%, 33.6% and 89.1%, and 85.9% and 83.5% respectively. Incomplete bioavailability in poultry is probably due to incomplete absorption in addition to first-pass elimination. Low bioavailability of R(-) ketoprofen in dogs, strongly indicates first-pass metabolism. High bioavailability of S(+) ketoprofen in dogs and both enantiomers in pigs confirms that absorption of these substances is complete and controlled by gastric emptying rather than dissolution.

Cardiovascular effects of epidural administration of methadone, ropivacaine 0.75% and their combination in isoflurane anaesthetized dogs

OBJECTIVE To compare the cardiovascular effects of four epidural treatments in isoflurane anaesthetised dogs. STUDY DESIGN Prospective, randomized. experimental study. ANIMALS Six female, neutered Beagle dogs (13.3±1.0 kg), aged 3.6±0.1 years. METHODS Anaesthesia was induced with propofol (8.3±1.1 mg kg(-1)) and maintained with isoflurane in a mixture of oxygen and air [inspiratory fraction of oxygen (FiO(2))=40%], using intermittent positive pressure ventilation. Using a cross-over model, NaCl 0.9% (P); methadone 1% 0.1 mg kg(-1) (M); ropivacaine 0.75% 1.65 mg kg(-1) (R) or methadone 1% 0.1 mg kg(-1) + ropivacaine 0.75% 1.65 mg kg(-1) (RM) in equal volumes (0.23 mL kg(-1)) using NaCl 0.9%, was administered epidurally at the level of the lumbosacral space. Treatment P was administered to five dogs only. Cardiovascular and respiratory variables, blood gases, and oesophageal temperature were recorded at T-15 and for 60 minutes after epidural injection (T0). RESULTS Mean overall heart rate (HR in beats minute(-1)) was significantly lower after treatment M (119±16) (p=0.0019), R (110±18) (p< 0.0001) and RM (109±13) (p<0.0001), compared to treatment P (135±21). Additionally, a significant difference in HR between treatments RM and M was found (p=0.04). After both ropivacaine treatments, systemic arterial pressures (sAP) were significantly lower compared to other treatments. No significant overall differences between treatments were present for central venous pressure, cardiac output, stroke volume, systemic vascular resistance, oxygen delivery and arterial oxygen content (CaO(2)). Heart rate and sAP significantly increased after treatment P and M compared to baseline (T-15). With all treatments significant reductions from baseline were observed in oesophageal temperature, packed cell volume and CaO(2) . A transient unilateral Horners syndrome occurred in one dog after treatment R. CONCLUSIONS AND CLINICAL RELEVANCE Clinically important low sAPs were observed after the ropivacaine epidural treatments in isoflurane anaesthetised dogs. Systemic arterial pressures were clinically acceptable when using epidural methadone.

Intraobserver, interobserver, and intermethod agreement for results of myelography, computed tomography-myelography, and low-field magnetic resonance imaging in dogs with disk-associated wobbler syndrome

OBJECTIVE To determine intraobserver, interobserver, and intermethod agreement for results of myelography, computed tomography-myelography (CTM), and low-field magnetic resonance imaging (MRI) in dogs with disk-associated wobbler syndrome (DAWS). DESIGN Prospective cross-sectional study. ANIMALS 22 dogs with DAWS. PROCEDURES All dogs underwent myelography, CTM, and low-field MRI. Each imaging study was interpreted twice by 4 observers who were blinded to signalment and clinical information of the patients. The following variables were assessed by all 3 techniques: number, site, and direction of spinal cord compressions; narrowed intervertebral disk spaces; vertebral body abnormalities; spondylosis deformans; and abnormal articular facets. Intervertebral foraminal stenosis was assessed on CTM and MRI images. Intraobserver, interobserver, and intermethod agreement were calculated by κ and weighted κ statistics. RESULTS There was very good to good intraobserver agreement for most variables assessed by myelography and only moderate intraobserver agreement for most variables assessed by CTM and low-field MRI. There was moderate to fair interobserver and intermethod agreement for most variables assessed by the 3 diagnostic techniques. There was very good or good intraobserver, interobserver, or intermethod agreement for the site and direction of the worst spinal cord compression as assessed by all the imaging modalities; abnormal articular facets and intervertebral foraminal stenosis were the least reliably assessed variables, with poor interobserver agreement regardless of imaging modality used. CONCLUSIONS AND CLINICAL RELEVANCE There was considerable variation in image interpretation among observers and between use of various imaging modalities; these imaging techniques should be considered complementary in assessment of dogs with DAWS.

TTA Rapid: Description of the Technique and Short Term Clinical Trial Results of the First 50 Cases

OBJECTIVE To (1) describe a modified technique for tibial tuberosity advancement (TTA) in dogs with cranial cruciate ligament (CCL) rupture and (2) report short term outcome and complications. STUDY DESIGN Prospective clinical study. ANIMALS Dogs with unilateral CCL rupture (n = 50). METHODS TTA was performed with a novel implant to achieve advancement of the tibial crest. The technical protocol, specific implants and instrumentation, and the short term outcome are described. RESULTS Various breeds (mean ± SD weight, 31.9 ± 13.3 kg) were included. Mean age at treatment was 64 ± 30.6 months. Minor complications occurred in 30% and major complications in 4% of the cases. Forty-eight (96%) dogs had a good to excellent outcome 3 months after surgery. CONCLUSION The modified technique is a viable alternative to other osteotomy techniques.

A Single Sample Method for Evaluating 51Chromium‐Ethylene Diaminic Tetraacetic Acid Clearance in Normal and Hyperthyroid Cats

BACKGROUND Chronic kidney failure is frequently seen in middle-aged and elderly cats. 51Chromium-ethylene diaminic tetraacetic acid (51Cr-EDTA) clearance and single blood sample (SBS) method are used in several species to estimate the glomerular filtration rate (GFR). HYPOTHESIS The hypothesis of this study was that 51Cr-EDTA clearance could be determined using an SBS method in normal and hyperthyroid cats. ANIMALS Forty-six cats were included in this study, with an average age of 9.5 years. Of these cats, 27 had hyperthyroidism; 19 were healthy. METHODS After IV injection of 51Cr-EDTA (average dose: 4.25 MBq), 7 blood samples were obtained between 5 and 240 minutes. Reference clearance was calculated in mL/min and mL/min/kg body weight, using a 2-compartment model. Optimal time for clearance measurement with SBS was then determined by systematically comparing each individual plasma concentration to the reference multisample clearance. RESULTS The average reference plasma clearance of 51Cr-EDTA for all cats was 14.9 mL/min (3.7 mL/min/kg). The clearance in hyperthyroid cats averaged 16.4 mL/min (4.3 mL/min/kg) and in normal cats averaged 10.3 mL/min (2.4 mL/min/kg). The optimal time for the SBS was 48 minutes after injection of tracer 51Cr-EDTA (R2= 0.9414), giving the following converting equation: clearance = (0.0066 x DV48 minutes) - 0.9277 (in mL/min). CONCLUSIONS AND CLINICAL IMPORTANCE In this study, the single sample 51Cr-EDTA clearance method was used to estimate the global GFR in cats. The method identified differences in clearance between normal and hyperthyroid cats. The optimal time for an SBS was 48 minutes.

Improved canine exome designs, featuring ncRNAs and increased coverage of protein coding genes

By limiting sequencing to those sequences transcribed as mRNA, whole exome sequencing is a cost-efficient technique often used in disease-association studies. We developed two target enrichment designs based on the recently released annotation of the canine genome: the exome-plus design and the exome-CDS design. The exome-plus design combines the exons of the CanFam 3.1 Ensembl annotation, more recently discovered protein-coding exons and a variety of non-coding RNA regions (microRNAs, long non-coding RNAs and antisense transcripts), leading to a total size of ≈152 Mb. The exome-CDS was designed as a subset of the exome-plus by omitting all 3’ and 5’ untranslated regions. This reduced the size of the exome-CDS to ≈71 Mb. To test the capturing performance, four exome-plus captures were sequenced on a NextSeq 500 with each capture containing four pre-capture pooled, barcoded samples. At an average sequencing depth of 68.3x, 80% of the regions and well over 90% of the targeted base pairs were completely covered at least 5 times with high reproducibility. Based on the performance of the exome-plus, we estimated the performance of the exome-CDS. Overall, these designs provide flexible solutions for a variety of research questions and are likely to be reliable tools in disease studies.

Surgical Treatment of Disk‐Associated Wobbler Syndrome by a Distractable Vertebral Titanium Cage in Seven Dogs

OBJECTIVE To evaluate a distractable titanium cage for the treatment of disk-associated wobbler syndrome (DAWS). STUDY DESIGN Prospective study. ANIMALS Dogs (n = 7) with DAWS. METHODS After total discectomy of C5-C6 and C6-C7, the median part of the vertebral body of C6 was removed with preservation of the lateral walls and dorsal cortex. The removed cancellous bone was collected. The implant was placed in the bony defect of C6. After placement, the titanium cage was distracted and affixed by 4 screws. Finally, the implant was filled and covered with cancellous bone. Dogs had follow-up examinations at 1, 3, 6, 12, and 24 months. Six months after surgery, cervical radiographs and computed tomography (CT) were performed. RESULTS Although no intraoperative complications occurred, correct placement of the cage was technically challenging. Revision surgery was necessary in 2 dogs because of implant loosening and aggravation of vertebral tilting. All dogs improved after discharge from the hospital. In 1 dog, recurrence of clinical signs caused by articular facet proliferation at an adjacent intervertebral disk space occurred. Radiographs at 6 months demonstrated cage subsidence in 4 dogs. In all dogs, CT was suggestive for fusion of the bone graft with the vertebral body. CONCLUSIONS Although results are promising, technical adaptations will be necessary to make this specific surgical technique, designed for humans, suitable for routine use in dogs.

Transient unilateral Horner’s syndrome after epidural ropivacaine in a dog

OBSERVATIONS A left sided Horners syndrome (ptosis, prolapse of the nictitating membrane and miosis) was observed in a 4-year-old female, neutered Beagle dog after epidural injection of 0.22 mL kg(-1) ropivacaine (0.75%) in 0.01 mL kg(-1) of saline during isoflurane anaesthesia. Clinical signs disappeared gradually and resolved completely 4 hours and 10 minutes after injection. CONCLUSIONS The epidural injection of 0.22 mL kg(-1) ropivacaine (0.75%) in 0.01 mL kg(-1) of saline during isoflurane anaesthesia caused unilateral (left) Horners syndrome in a 4-year-old female, neutered Beagle dog.

Prepubertal gonadectomy in cats: different injectable anaesthetic combinations and comparison with gonadectomy at traditional age

Anaesthetic and analgesic effects of three different injectable anaesthetic combinations for prepubertal gonadectomy (PPG) in cats were studied. One anaesthetic protocol was compared with a similar one for gonadectomy at traditional age (TAG). Kittens were randomly assigned to PPG or TAG. For PPG, three different protocols were compared: (1) intramuscular (IM) administration of 60 μg/kg dexmedetomidine plus 20 μg/kg buprenorphine followed by an IM injection of the anaesthetic agent (20 mg/kg ketamine) (DB-IM protocol); (2) oral transmucosal (OTM) administration of 80 μg/kg dexmedetomidine plus 20 μg/kg buprenorphine followed by an IM injection of 20 mg/kg ketamine combined with 20 µg/kg dexmedetomidine (DB-OTM protocol); (3) IM injection of a 40 μg/kg medetomidine–20 μg/kg buprenorphine–20 mg/kg ketamine combination (MBK-IM protocol). For TAG, a DB-IM protocol was used, but with different doses for dexmedetomidine (40 μg/kg) and ketamine (5 mg/kg). All cats (PPG and TAG) received a non-steroidal anti-inflammatory before surgery. Anaesthetic and analgesic effects were assessed pre- and postoperatively (until 6 h). Cumulative logit, linear and logistic regression models were used for statistical analysis. Compared with the DB-OTM protocol, the DB-IM and MBK-IM protocols provided better anaesthesia with fewer adverse effects in PPG cats. Postoperative pain was not significantly different between anaesthetic protocols. PPG and TAG cats anaesthetised with the two DB-IM protocols differed significantly only for sedation and pain scores, but sedation and pain scores were generally low. Although there were no anaesthesia-related mortalities in the present study and all anaesthetic protocols for PPG in cats provided a surgical plane of anaesthesia and analgesia up to 6 h postoperatively, our findings were in favour of the intramuscular (DB-IM and MBK-IM) protocols.