CT features of subcutaneous, intermuscular, and intramuscular mast cell tumors in dogs.

Surgical removal is the treatment of choice for subcutaneous (SC), intermuscular (InterM), and intramuscular (IntraM) mast cell tumors (MCTs). Advanced imaging (CT or MRI) is frequently used for presurgical planning, but InterM and IntraM MCTs can be difficult to identify and delineate on CT. Aims of the current retrospective, diagnostic accuracy, observer agreement study were to describe the imaging features of SC, InterM, and IntraM MCTs on CT and to assess the limitation of CT to identify the full local extent of the MCT. Inclusion criteria for the study were dogs with a cytologically or histologically diagnosed MCTs determined to be SC, InterM, or IntraM MCT based on histology and/or a CT scan performed in the gross disease setting. Two board-certified veterinary radiologists reviewed the CT images and recorded location, contrast enhancement pattern, and delineation between the normal and abnormal tissue. Sensitivity and specificity of CT for determining location (SC/InterM versus IntraM) was 85.71% and 55.56%, respectively, when compared to consensus location based on surgical pathology report/CT/MRI review. There was a low inter-rater agreement for delineation (kappa: 0.150 (-0.070 to 0.370) and measurement had a low/moderate correlation (rho: 0.4667 to 0.5792). Upon review by a surgical oncologist, CT findings were deemed insufficient for curative surgical planning in 13 of 16 due to inadequate definition of tumor depth, compartment boundary (fascial plane) or MCT margins. The use of CT for presurgical planning of SC/InterM/IntraM MCT dogs has limitations, especially when differentiating MCT from the adjacent muscle.

Development and Validation of a Three-Dimensional Printed Training Model to Teach Ultrasound-Guided Injections of the Cervical Articular Process Joints in Horses.

Intra-articular injections are routinely performed to alleviate pain and inflammation associated with osteoarthritis in horses. Intra-articular injections require accurate needle placement to optimize clinical outcomes and minimize complications. This study's objectives were to develop and validate a three-dimensional (3D) printed model of an equine cervical articular process joint to teach ultrasound-guided injections. Five identical models of an equine cervical articular process joint were 3D printed and embedded in 10% ballistic gelatin. Experts' and novices' ability to successfully insert a needle into the joint space of the model using ultrasound guidance was assessed and graded using an objective structured clinical examination (OSCE). Scores from experts and novices were compared to evaluate the construct validity of the model. Participants also answered a survey assessing the face and content validity of the model. Experts required less time (22.51 seconds) for correct needle placement into the model joint space than novices (35.96 seconds); however, this difference was not significant (p = .53). Experts' median total OSCE score (14) was significantly higher (p = .03) than novices' (12), supporting the model's construct validity. Participants agreed on the face and content validity of the model by grading all survey questions greater than 7 on a 10-point Likert-type scale. In summary, we successfully developed a 3D printed model of an equine cervical articular process joint, partially demonstrated the construct validity of the model, and proved the face and content validity of this new training tool.

MRI has limited agreement with CT in the evaluation of vertebral fractures of the canine trauma patient.

Complete assessment of vertebral trauma in dogs currently requires CT and MRI for evaluation of the osseous and soft tissue structures that contribute to vertebral stability. Some studies in people have suggested that MRI may be sensitive and specific at detecting vertebral fractures making this potentially a single modality that could be used in spinal trauma evaluation. This study aimed to assess the ability for observers to evaluate vertebral fractures using MRI when compared to CT, which was used as the reference standard. Twenty-nine dogs with previously diagnosed acute vertebral fractures and four dogs with no vertebral fracture that had undergone sequential CT and MRI were included into the study. One hundred twenty-eight vertebrae were evaluated for the presence of fractures. Imaging studies were read by two observers blinded to the history. While both observers had similarly high sensitivity and specificity for simple detection of any fractured vertebrae, interobserver agreement was only moderate (κ = 0.584). When evaluations were specifically limited to detection of structurally unstable fractured vertebrae both observers showed improved specificity and interobserver agreement became substantial (κ = 0.650). Complete agreement for exact fracture location between MRI and CT results was only achieved in 14.3-32.6% of fractured vertebra with up to 79% of fractures being missed in some vertebral structures. This suggests that although MRI may be able to detect the presence of fractured vertebrae, it is not able to replace CT for the complete evaluation of the traumatized spine and documentation of fracture morphology.

Efficiency of ultrasound-guided aspiration of medial retropharyngeal lymph node in dogs.

The purpose of this retrospective cross-sectional study was to assess the diagnostic yield of ultrasound-guided aspiration of the medial retropharyngeal lymph node (MRPLN) and to report factors on computed tomography (CT) evaluation that are predictive of obtaining a diagnostic sample. A secondary objective was to report CT size reference ranges for cytologically confirmed normal MRPLNs in dogs. Medical records and CT images of 69 dogs were retrospectively reviewed. The diagnostic yield of ultrasound-guided aspiration on MRPLNs was 47.5%. Six lymph nodes were positive for metastasis with various cancers. Only rostral height was predictive of the diagnostic yield. The Pearson correlation coefficient and Spearman's Rho tests suggested that the age of the dog has significant negative linear correlation with the size of MRPLNs while the weight has positive correlation. Overall, ultrasound-guided aspiration of MRPLN has low diagnostic yield in normal size lymph nodes. Prior case selection based on CT evaluation may increase the probability of diagnostic samples.

Efficacité de l'aspiration guidée par échographie des ganglions lymphatiques rétro-pharyngiens médiaux et caractéristiques de la tomodensitométrie chez les chiens. Le but de cette étude transversale rétrospective était d'évaluer les résultats diagnostiques de l'aspiration guidée par échographie des ganglions lymphatiques rétropharyngiens médiaux (GLRM) et de faire rapport sur les facteurs de l'évaluation par tomodensitométrie qui sont prédicteurs de l'obtention d'un échantillon diagnostique. Un objectif secondaire était de faire rapport sur les écarts de référence de taille de la tomographie par ordinateur pour les GLRM confirmés normaux par cytologie chez les chiens. Les dossiers médicaux et les images de la tomodensitométrie de 69 chiens ont été évalués rétrospectivement. Le résultat diagnostique de l'aspiration guidée par échographie des GLRM était de 47,5 %. Six ganglions lymphatiques étaient positifs pour la présence de métastase de divers cancers. Seule la taille rostrale était prédictive du résultat diagnostique. Le coefficient de corrélation de Pearson et les tests Rho de Spearman ont suggéré que l'âge du chien avait une corrélation linéaire significativement négative avec la taille des GLRM tandis que le poids avait une corrélation positive. En général, l'aspiration guidée par échographie des GRLM présente un faible rendement diagnostique pour les ganglions lymphatiques de taille normale. Une sélection des cas préalable fondée sur l'évaluation de la tomodensitométrie pourra accroître la probabilité des échantillons diagnostiques.(Traduit par Isabelle Vallières).

Magnetic resonance imaging muscle lesions in presumptive canine fibrocartilaginous embolic myelopathy.

This retrospective cohort study reports the observation of magnetic resonance imaging (MRI) epaxial muscle hyperintensity in dogs diagnosed with presumptive fibrocartilaginous embolic myelopathy (FCEM) (n = 61). It further reports the observation of vertebral column hyperesthesia lasting > 12 hours. The hypothesis tested was that the finding of MRI epaxial muscle hyperintensity correlated with dogs presenting with hyperesthesia. Client-owned dogs diagnosed with presumptive FCEM by specific MRI criteria were included. Statistical analysis was performed using Fisher's exact test. Twenty-three percent (14/61) of MRIs displayed abnormal muscle hyperintensity and 43% (26/61) exhibited vertebral column hyperesthesia. No relationship was found between muscle hyperintensity and pain persisting beyond 12 hours. The muscle hyperintensity remains of unknown significance. That 43% of presumptive FCEM cases have prolonged signs of pain is a higher prevalence than previously reported, and may affect clinical differential diagnoses. This is especially significant in cases in which MRI is not possible and a presumptive diagnosis must be based on the clinical signs.

Imagerie par résonance magnétique des lésions des muscles dans la myélopathie embolique fibrocartilagineuse canine présumée. Cette étude rétrospective de cohorte signale les observations de l'imagerie par résonance magnétique (IRM) pour l'hyperintensité du muscle épaxial chez les chiens diagnostiqués avec une myélopathie embolique fibrocartilagineuse (MEFC) présumée (n = 61). Elle signale aussi l'observation de l'hyperesthésie de la colonne vertébrale durant > 12 heures. L'hypothèse qui a été testée était qu'il y avait une corrélation entre l'observation de l'hyperintensité du muscle épaxial par IRM et les chiens présentés avec de l'hyperesthésie. Les chiens appartenant à des clients pour lesquels un diagnostic présomptif de MEFC avait été posé à l'aide du critère spécifique de l'IRM ont été inclus. L'analyse statistique a été réalisée en utilisant le test exact de Fisher. Vingt-trois pour cent (14/61) des IRM affichaient une hyperintensité anormale du muscle et 43 % (26/61) présentaient de l'hypersthésie de la colonne vertébrale. Aucun lien n'a été trouvé entre l'hyperintensité musculaire et la douleur persistant au-delà de 12 heures. La signification de l'hyperintensité musculaire est toujours inconnue. Le taux de 43 % de cas présomptifs de MEFC affichant des signes de douleur prolongée représente une prévalence supérieure aux données déjà signalées et pourrait affecter les diagnostics cliniques différentiels. Ce fait revêt une importance particulière lorsque l'IRM n'est pas possible et qu'un diagnostic présomptif doit se baser sur les signes cliniques.(Traduit par Isabelle Vallières).

The magnitude of muscular activation of four canine forelimb muscles in dogs performing two agility-specific tasks.

BACKGROUND: The purpose of this study was to measure the muscular activation in four forelimb muscles while dogs performed agility tasks (i.e., jumping and A-frame) and to provide insight into potential relationships between level of muscular activation and risk of injury. Muscle activation in eight healthy, client-owned agility dogs was measured using ultrasound-guided fine-wire electromyography of four specific forelimb muscles: Biceps Brachii, Supraspinatus, Infraspinatus, and Triceps Brachii - Long Head, while dogs performed a two jump sequence and while dogs ascended and descended an A-frame obstacle at two different competition heights. RESULTS: The peak muscle activations during these agility tasks were between 1.7 and 10.6 fold greater than walking. Jumping required higher levels of muscle activation compared to ascending and descending an A-frame, for all muscles of interest. There was no significant difference in muscle activation between the two A-frame heights. CONCLUSIONS: Compared to walking, all of the muscles were activated at high levels during the agility tasks and our findings indicate that jumping is an especially demanding activity for dogs in agility. This information is broadly relevant to understanding the pathophysiology of forelimb injuries related to canine athletic activity.

OPHTHALMIC REFERENCE VALUES AND LESIONS IN TWO CAPTIVE POPULATIONS OF NORTHERN OWLS: GREAT GREY OWLS (STRIX NEBULOSA) AND SNOWY OWLS (BUBO SCANDIACUS).

This study established ophthalmic reference values and characterized ocular lesions in two captive populations of boreal owls, including 46 eyes of 23 great grey owls (Strix nebulosa) and 38 eyes from 19 snowy owls (Bubo scandiacus). A complete ophthalmologic exam was conducted, including neuro-ophthalmic reflexes, Schirmer tear test I (STT-I), intraocular pressure (IOP) using rebound tonometry, fluorescein staining, horizontal corneal measurements using Jameson calipers, direct and indirect ophthalmoscopy, and ocular ultrasound biometry. Eyes with an STT of <5 mm/min, outliers, and eyes with severe diseases were excluded from reference value analysis. No statistically significant differences were found between right or left eyes in either species or among individuals in different age groups and sexes. Mean intraocular pressures and Schirmer tear tests were also not statistically significantly different between great grey owls and snowy owls (IOP: 9.6 ± 2.6 mm Hg and 9.1 ± 1.9 mm Hg, respectively, and STT-I: 9.8 ± 2.8 mm/min and 9.8 ± 2.4 mm/min, respectively). However, snowy owls overall had a significantly larger eye than did great grey owls, reflected in corneal diameters (23.4 ± 1 vs. 20.0 ± 0.8 mm, respectively) and sonographic biometry. In both species, the most common ocular lesions included keratitis, cataracts, chorioretinal lesions, and abnormal pecten. Establishment of reference ocular parameters will help wildlife veterinarians and rehabilitators determine an appropriate treatment plan and will aid in correctly identifying the presence of ocular disease.

Presence of residual material following mini-hemilaminectomy in dogs with thoracolumbar intervertebral disc extrusion.

Presence of residual material following mini-hemilaminectomy in dogs (n = 9) with spontaneous thoracolumbar intervertebral disc extrusion was prospectively investigated. Volume of extruded disc material within the vertebral canal and the proportion of residual material were determined using pre- and post-operative magnetic resonance imaging. The degree of spinal cord compression, proportion of extradural material considered hemorrhage, and invasion of the articular facets were also determined. Residual material was identified in 44% of the mini-hemilaminectomies. The median percentage of residual material calculated was 7.7% of the preoperative volume. No observed effect of surgical side or site, proportion of extradural material considered hemorrhage, patient weight, and duration of clinical signs was detected.

Présence de matières résiduelles après une mini-hémilaminectomie chez des chiens avec une extrusion d'un disque intervertébral thoracolombaire. La présence de matières résiduelles après une mini-hémilaminectomie chez les chiens (n = 9) avec une extrusion spontanée d'un disque intervertébral thoracolombaire a fait l'objet d'une étude prospective. Le volume de fragment discal exclu dans le canal vertébral et la proportion de matières résiduelles ont été déterminés en utilisant une imagerie par résonance magnétique avant et après l'opération. Le degré de compression de la moelle épinière, la proportion de matières extradurales considérées comme de l'hémorragie et l'invasion des facettes articulaires ont aussi été déterminés. Les matières résiduelles ont été identifiées dans 44 % des mini-hémilaminectomies. Le pourcentage médian des matières résiduelles calculé s'établissait à 7,7 % du volume préopératoire. Aucun effet observé pour le côté ou le site chirurgical, la proportion des matières résiduelles considérées comme de l'hémorragie, le poids du patient et la durée des signes cliniques n'a été détecté.(Traduit par Isabelle Vallières).

Comparison of the access window created by hemilaminectomy and mini-hemilaminectomy in the thoracolumbar vertebral canal using computed tomography.

Hemilaminectomy and mini-hemilaminectomy were performed on opposite sides of the spine at T11-T12, T13-L1, and L2-L3 in 11 canine cadavers in order to report differences in the access provided to the thoracolumbar vertebral canal. Measurements of the vertebral canal height, defect height, and dorsal and ventral remnants of the vertebral arch were obtained after computed tomography. A median of 7% to 20% of the vertebral canal height was not removed dorsally after mini-hemilaminectomy compared to 1% to 2% in hemilaminectomy. Thirteen to 25% of the vertebral canal height was left ventrally in mini-hemilaminectomy and 11% to 27% in hemilaminectomy. Potential for a restricted exposure of thoracolumbar lesions should be considered if lesions are located in the ventral 11% to 27% vertebral canal height when performing either procedure or in the dorsal 7% to 20% of the canal height when performing a mini-hemilaminectomy.

Comparaison, à l'aide de tomodensitométrie, de la fenêtre d'accès créée par une hémilaminectomie et une mini-hémilaminectomie dans le canal vertébral thoracolombaire. Une hémilaminectomie et une mini-hémilaminectomie ont été réalisées sur les côtés opposés de la colonne vertébrale à T11­T12, à T13-L1 et à L2­L3 sur 11 cadavres canins afin de signaler les différences de l'accès fourni au canal vertébral thoracolombaire. Les mesures de la hauteur du canal vertébral et des vestiges dorsaux et ventraux de l'arc vertébral ont été obtenues après une tomodensitométrie. Une médiane de 7 % à 20 % de la hauteur du canal vertébral n'a pas été enlevée dorsalement après une mini-hémilaminectomie comparativement à 1 % ou 2 % pour une hémilaminectomie. De 13 % à 25 % de la hauteur du canal vertébral a été laissée ventralement dans la mini-hémilaminectomie et de 11 % à 27 % dans l'hémilaminectomie. Le potentiel d'une exposition restreinte des lésions thoracolombaires devrait être considéré si les lésions sont situées dans le 11 % à 27 % de la portion ventrale de la hauteur du canal vertébral lors de la réalisation des deux interventions ou dans le 7 % à 20 % de la portion dorsale de la hauteur du canal lors de la réalisation d'une mini-hémilaminectomie.(Traduit par Isabelle Vallières).

Focal thoracolumbar spinal cord lymphosarcoma in a ferret (Mustela putorius furo).

A 6-year-old, castrated male domestic ferret (Mustela putorius furo) was euthanized following progressive hind limb paresis and atonia of the bladder of 1-year duration. Neurological evaluation localized the lesion to the thoracolumbar spinal region, and magnetic resonance imaging showed a focal intramedullary spinal cord lesion. Histopathology revealed an extensive, unencapsulated, poorly demarcated mass within the thoracolumbar spinal cord, diagnosed as lymphosarcoma.

Lymphosarcome thoraco-lombaire localisé dans la moelle épinière chez un furet(Mustela putorius furo) . Un furet domestique (Mustela putorius furo) mâle castré âgé de 6 ans a été euthanasié après une parésie progressive des membres postérieurs et une atonie de la vessie d'une durée de 1 an. L'évaluation neurologique a repéré la lésion dans la région de la moelle épinière thoraco-lombaire et une imagerie par résonance magnétique a indiqué une lésion intramédullaire localisée dans la moelle épinière. L'histopathologie a révélé une masse importante, acapsulée et faiblement démarquée dans la moelle épinière thoraco-lombaire qui a été diagnostiquée comme un lymphosarcome.(Traduit par Isabelle Vallières).

Canine preclinical safety evaluation of a multimodal nanoparticle agent (Nanotrast-CF800) for image-guided cancer surgery.

Surgical oncology often requires the use of contrast-enhanced cross-sectional imaging preoperatively to characterize solitary tumours and identify sentinel lymph nodes. Intraoperative optical guidance can effectively aid tissue-sparing tumour excision and locate sentinel lymph nodes. Nanotrast-CF800 (CF800) is a novel dual-modality contrast agent, which co-encapsulates iohexol and indocyanine green (ICG) within a liposomal nanoparticle. It was developed for preoperative and intraoperative imaging of solitary tumours and sentinel lymph node mapping and its efficacy has been demonstrated in preclinical animal models (Zheng et al. 2015). The objective of this study is to evaluate the safety profile of CF800 following intravenous administration in healthy dogs. Six research dogs were randomized into two groups. Group 1 received a low dose (1 mL/kg) and group 2 received a high dose (5 mL/kg). Dogs were placed under general anesthesia and a continuous rate infusion of CF800 was administered based on group allocation. Physiologic parameters including heart rate, respiratory rate, direct arterial blood pressure, cardiac output, and temperature were measured at set time points. Plasma concentrations of iohexol, ICG, and histamine were measured at set time points. Dogs underwent whole body computed tomography scans pre-injection, 2-, and 7-days post-injection (p.i.). Contrast enhancement was measured in select organ systems and great vessels at each time point. There were no significant changes in physiologic parameters following IV infusion of CF800 in all dogs. Plasma iohexol and ICG concentrations peaked at 1 day p.i., while histamine concentrations peaked at 30 minutes p.i. Significant contrast enhancement was noted within the liver, heart, aorta, and caudal vena cava on day 2 p.i., which was significantly different compared to baseline. Prolonged contrast retention within the liver was identified. Intravenous administration of CF800 was safe to use in healthy dogs with no significant systemic adverse effects.

Reason for euthanasia in dogs with urothelial carcinoma treated with chemotherapy or radiation therapy or both: A retrospective observational study.

BACKGROUND: Clients want to know the ultimate cause of death in their pet after cancer treatment. The cause of euthanasia and investigation of urinary obstruction in treated dogs with urothelial carcinoma (UC) has not been specifically reported in veterinary literature. HYPOTHESIS/OBJECTIVES: Our hypothesis was that the majority of treated dogs with UC are euthanized secondary to primary tumor factors, such as urinary obstruction. ANIMALS: Fifty-nine client-owned dogs diagnosed with UC. METHODS: Retrospective observational study on clinical signs and disease at euthanasia of dogs with UC treated by radiation therapy or chemotherapy or both. RESULTS: The median overall survival time (OST) of all dogs was 339 days (range, 17-1996; 95% confidence interval [CI], 185-392; interquartile range [IQR], 112-505). Of dogs deemed to have been euthanized because of UC (50/59, 85%), the primary cause was considered to be local progression in 31/50 (62%), most often because of perceived complete or partial urinary obstruction (24/31, 77%). No variables were found to be predictive of urinary obstruction. The overall documented metastatic rate was 56%. In dogs euthanized because of UC, metastasis was deemed to be the cause in 19/50 (38%) dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Regardless of the type of treatment, UC in dogs has a poor prognosis and there is a continuing need to improve treatments that focus on local control of the primary tumor, given its high contribution to the decision for euthanasia. Proactive management to avoid the high frequency of urinary obstruction may be worthy of future investigation.

The Ontario Veterinary College Hip Certification Program -- assessing inter- and intra-observer repeatability and comparison of findings to those of the Orthopedic Foundation for Animals.

In Canada, the Ontario Veterinary College (OVC) has offered radiographic screening for hip dysplasia for many years, but there are other options for this service including the Orthopedic Foundation for Animals (OFA). There are some differences between the OFA and the OVC methods, and this study compares the OVC and OFA hip certification results in 37 dogs. There was good agreement between the two programs but in some instances there was a difference in the pass/fail status of a dog. Neither the OFA nor the OVC was more likely to fail or pass a given dog. The repeatability of the OVC results was assessed by both inter- and intra-observer comparisons in 100 dogs. There was at least 86% agreement among and within radiologists, but in 5 cases the disagreement resulted in a difference in the pass/fail status of the dog. These results illustrate the inherent variation in radiographic hip evaluation and highlight the importance of consensus grading practices to improve the accuracy of hip evaluation.

Programme de certification des hanches de l'Ontario Veterinary College ­ Évaluation de la reproductibilité inter- et intra-observateur et comparaison des résultats à ceux de l'Orthopedic Foundation for Animals. Au Canada, l'Ontario Veterinary College (OVC) offre le dépistage radiographique de la dysplasie de la hanche depuis de nombreuses années, mais il y a d'autres options pour ce service, incluant l'Orthopedic Foundation for Animals (OFA). Il y a certaines différences entre les méthodes de l'OFA et de l'OVC et cette étude compare les résultats de certification de la hanche de l'OVC et de l'OFA chez 37 chiens. Il y avait une bonne concordance entre les deux programmes, mais dans certains cas, il y avait une différence au niveau du statut d'échec-réussite d'un chien. Ni l'OFA ni l'OVC ne présentait une probabilité accrue de donner un résultat d'échec ou de réussite à un chien particulier. La reproductibilité des résultats de l'OVC a été évaluée par des comparaisons inter- et intra-observateur chez 100 chiens. Il y avait au moins 86 % de concordance entre et parmi les radiologistes, mais dans 5 cas, la discordance s'est traduite par une différence du statut de réussite et d'échec chez le chien. Les résultats illustrent la variation inhérente à l'évaluation radiographique de la hanche et souligne l'importance de pratiques de classification par consensus afin d'améliorer l'exactitude de l'évaluation de la hanche.(Traduit par Isabelle Vallières).

Acute intraparenchymal spinal cord injury in a cat due to high-rise syndrome.

A 9-year-old spayed female Bengal Red cat was evaluated for high-rise syndrome. The cat had paraplegia of the hind limbs, intact reflexes and pain perception, and hyperesthesia in the caudal thoracic area. Mentation, cranial nerve function, forelimb proprioceptive responses, and spinal reflexes were normal. There were no abnormalities on radiographs or computed tomography scan, but magnetic resonance imaging revealed a hyperintense intraparenchymal spinal cord lesion on T2-weighted and T2 fat saturation images.

Ultrasonographic and laboratory screening in clinically normal mature golden retriever dogs.

Wellness and pre-anesthetic screening of blood and urine of geriatric companion animals are routinely recommended. In addition, there are occasional references to the use of imaging in clinically normal geriatric patients. However, the utility of wellness testing is not known, and there is limited information regarding the value of pre-anesthetic testing. Wellness testing, including complete blood cell count, biochemical profile, urinalysis, and abdominal ultrasound, was performed on 53 clinically normal, mature golden retriever dogs. Laboratory analysis revealed abnormalities in 54.7% (29/53) of the dogs. Abdominal ultrasound screening demonstrated abnormalities in 64.2% (34/53) of the dogs. As only a small number of dogs had follow-up diagnostic testing available, the significance of these abnormalities is unknown. Further study involving a larger cohort of animals and analysis of follow-up data is necessary to determine the utility of laboratory and imaging studies in clinically normal geriatric patients.

Comparison of computed tomographic and radiographic popliteal lymphangiography in normal dogs.

OBJECTIVE: To (1) describe computed tomographic (CT) popliteal lymphangiography; (2) compare the number of thoracic duct (TD) branches detected by CT and by radiography after popliteal lymphangiography; and (3) to compare the number of branches detected after left and right popliteal lymphangiography. STUDY DESIGN: Experimental study. ANIMALS: Adult dogs (n=6). METHODS: A randomly selected popliteal lymph node was percutaneously injected with 12 L iodinated contrast medium through a 25-g butterfly catheter over 4-5 minutes. Lateral and ventrodorsal (VD) thoracic radiograph projections and thoracic CT were performed. The procedure was repeated using the contralateral lymph node after a 48-72 hours washout period. RESULTS: One dog had TD branches visible on CT but not on radiographs. A significantly greater number of TD branches were observed with CT popliteal lymphangiography compared with lateral and VD radiographic popliteal lymphangiography (P=.003 and P<.001, respectively). The number of visible TD branches observed between the 6th thoracic and 1st lumbar vertebrae were not significantly different in these dogs (P=.146). A significant difference in number of TD branches observed was not found after left or right popliteal lymph node injection (P=.097). CONCLUSIONS: CT popliteal lymphangiography consistently identified a greater number of TD branches when compared with radiographic popliteal lymphangiography. Injection of either popliteal lymph node resulted in the same number of TD branches being observed.

Metastatic transitional cell carcinoma in proximal humerus of a dog.

Transitional cell carcinoma (TCC) was diagnosed in the proximal humerus of a dog that was presented with persistent right forelimb lameness with no clinical signs of urinary tract involvement. A diagnosis of TCC was made from surgical biopsy of the humeral lesion with subsequent necropsy revealing the prostatic urethra as the primary site of the tumor.

Determining agreement between preoperative computed tomography lymphography and indocyanine green near infrared fluorescence intraoperative imaging for sentinel lymph node mapping in dogs with oral tumours.

Lymphatic drainage from the head and neck is variable with significant crossover, therefore sentinel lymph node (SLN) mapping can help ensure the appropriate lymph node(s) are sampled. To improve sensitivity, SLN mapping utilizing multiple modalities and a combination of preoperative computed tomography lymphography (CTL) and intraoperative near infrared fluorescence imaging (NIRF) with indocyanine green (ICG) +/- methylene blue (MB) dye has been suggested. The aim of this study was to describe a method for intraoperative ICG lymphography and determine agreement for SLN detection using preoperative CTL and intraoperative ICG NIRF + MB lymphography (IOL) in dogs with oral tumours. Fourteen client-owned dogs were included. All dogs had preoperative CTL with iodinated contrast and intraoperative IOL with an exoscope. Lymph nodes with CTL contrast-enhancement, blue staining or fluorescence were considered sentinel. The overall SLN identification rate was 100% when CTL and IOL were combined. A total of 57 SLNs were identified. Indocyanine green NIRF identified a greater proportion of SLNs (91%; 52/57) compared with MB (50.8%; 29/57) and CTL (42.1%; 24/57). Eighteen SLNs were identified by all three modalities with a fair level of agreement using Fleiss kappa. These findings suggest a combination of preoperative CTL with intraoperative SLN mapping techniques may greatly improve the ability to accurately detect the SLN in dogs with oral tumours.

Evaluating the Feasibility and Efficacy of a Dual-Modality Nanoparticle Contrast Agent (Nanotrast-CF800) for Image-Guided Sentinel Lymph Node Mapping in the Oral Cavity of Healthy Dogs.

A combination of pre and intraoperative sentinel lymph node (SLN) mapping techniques have been suggested to optimize SLN detection. A novel liposomal nanoparticle, Nanotrast-CF800 (CF800), utilizes computed tomography lymphography (CTL) and near infrared fluorescence imaging (NIRF) for image-guided surgery and SLN mapping. This novel tracer agent has not been evaluated in companion animals. The objective of this study was to evaluate the feasibility and efficacy of CF800 for SLN mapping in the oral cavity of healthy dogs and to report any local adverse effects. Six healthy adult purpose-bred research dogs randomly received either 1 mL (group 1) or 2 mL (group 2) of CF800 injected into the submucosa at the level of the right canine maxillary tooth. CTL and percutaneous NIRF were performed at 1, 3, and 10 min, then 1, 2, 4, 7, and 10 days post-injection (p.i). Overall, both CTL and NIRF identified SLNs in all dogs. The overall peak mean contrast enhancement of the SLNs was 73.98 HU (range 63.45-86.27 HU) at 2 days p.i. Peak fluorescence of the SLN occurred at 1 day p.i. The agent was retained within the SLN for at least 7 days for CTL and 4 days for percutaneous NIRF. No adverse effects were observed. Local administration of CF800 was simple and feasible for the detection of SLNs using CTL+NIRF in the head and neck of healthy dogs and was not associated with significant local adverse events.

Seizure frequency discrepancy between subjective and objective ictal electroencephalography data in dogs.

BACKGROUND: Many studies of epilepsy in veterinary medicine use subjective data (eg, caregiver-derived histories) to determine seizure frequency. Conversely, in people, objective data from electroencephalography (EEG) are mainly used to diagnose epilepsy, measure seizure frequency and evaluate efficacy of antiseizure drugs. These EEG data minimize the possibility of the underreporting of seizures, a known phenomenon in human epileptology. OBJECTIVE: To evaluate the correlation between reported seizure frequency and EEG frequency of ictal paroxysmal discharges (PDs) and to determine whether seizure underreporting phenomenon exists in veterinary epileptology. ANIMALS: Thirty-three ambulatory video-EEG recordings in dogs showing ≥1 ictal PD, excluding dogs with status epilepticus. METHODS: Retrospective observational study. Ictal PDs were counted manually over the entire recording to obtain the frequency of EEG seizures. Caregiver-reported seizure frequency from the medical record was categorized into weekly, daily, hourly, and per minute seizure groupings. The Spearman rank test was used for correlation analysis. RESULTS: The coefficient value (rs ) comparing reported seizure to EEG-confirmed ictal PD frequencies was 0.39 (95% confidence interval [CI] = 0.048-0.64, P = .03). Other rs values comparing history against various seizure types were: 0.36 for motor seizures and 0.37 for nonmotor (absence) seizures. CONCLUSIONS AND CLINICAL IMPORTANCE: A weak correlation was found between the frequency of reported seizures from caregivers (subjective data) and ictal PDs on EEG (objective data). Subjective data may not be reliable enough to determine true seizure frequency given the discrepancy with EEG-confirmed seizure frequency. Confirmation of the seizure underreporting phenomenon in dogs by prospective study should be carried out.