Thymic carcinosarcoma with melanocytic differentiation in a dog.

Carcinosarcomas are very rare tumors in dogs. Although carcinosarcomas with melanocytic differentiation arising from organs other than the thymus have been described in humans, this type of tumor has not been reported in dogs in any part of the body. We observed such a tumor in the cranial mediastinum of an 11-year-old spayed female dachshund. The dog was admitted to the clinic because of coughing, sporadic regurgitation, and dyspnea. Thoracic ultrasonography and computed tomography revealed a large mediastinal mass that was surgically removed via sternotomy. The tumor was of thymic origin and demonstrated 3 distinct components: an epithelial component positive for pancytokeratin (AE1/AE3) and high molecular weight cytokeratin (CK5/CK6) with some cystic spaces; a mesenchymal component positive for vimentin; and in association with the epithelial part, a minor melanocytic component positive for Melan A. Histologic metastasis of the epithelial and melanocytic components was present within a tracheobronchial lymph node. The dog died 105 d after surgery, after an episode of acute dyspnea. Key clinical message: To the authors' knowledge, this is the first report of thymic carcinosarcoma with melanocytic differentiation.

Carcinosarcome thymique avec différenciation mélanocytaire chez un chienLes carcinosarcomes sont des tumeurs très rares chez le chien. Bien que des carcinosarcomes avec différenciation mélanocytaire provenant d'organes autres que le thymus aient été décrits chez l'homme, ce type de tumeur n'a été rapporté chez le chien dans aucune partie du corps. Nous avons observé une telle tumeur dans le médiastin cránien d'une femelle teckel stérilisée de 11 ans. Le chien a été admis à la clinique en raison de toux, de régurgitations sporadiques et de dyspnée. L'échographie thoracique et la tomodensitométrie ont révélé une masse médiastinale importante qui a été retirée chirurgicalement par sternotomie. La tumeur était d'origine thymique et présentait 3 composantes distinctes : une composante épithéliale positive pour la pancytokératine (AE1/AE3) et la cytokératine de haut poids moléculaire (CK5/CK6) avec quelques espaces kystiques; un composant mésenchymateux positif à la vimentine; et en association avec la partie épithéliale, un composant mélanocytaire mineur positif pour Melan A. Des métastases histologiques des composants épithéliaux et mélanocytaires étaient présentes dans un ganglion lymphatique trachéobronchique. Le chien est décédé 105 jours après l'intervention chirurgicale, à la suite d'un épisode de dyspnée aiguë.Message clinique clé :À la connaissance des auteurs, il s'agit du premier cas de carcinosarcome thymique avec différenciation mélanocytaire.(Traduit par Dr Serge Messier).

The Successful Use of an Ultrasound-Guided Mid-Femur Sciatic Nerve Block in a Juvenile Emu (Dromaius novaehollandiae) under General Anaesthesia.

The current case report describes a successful ultrasound-guided mid-femur sciatic nerve block in an emu. A 2-month-old emu suffering from acute-onset lameness was referred to the University Clinic of Liège, where he was diagnosed with a lateral luxation of the Achilles tendon on both hind limbs. Two surgical procedures were performed for treatment. Both surgical procedures were performed under general anaesthesia with butorphanol, ketamine, midazolam and isoflurane in oxygen. The anaesthesia was continuously monitored. An ultrasound-guided sciatic nerve block was performed to prevent and treat surgically induced nociception. The technique was adapted from what is already described in other species. Levobupivacaine was injected perineurally under ultrasound-guidance. Intraoperative nociception was assessed based on the heart rate and mean arterial pressure changes. The recovery was uneventful and with no clinical signs of postoperative pain.

Effect of the surface geometry of uncemented acetabular cups on primary stability in a model of uncemented total hip replacement in dogs.

OBJECTIVE: To compare the in vitro stability of acetabular cups with peripherally reinforced fixation in a model of uncemented total hip replacement in dogs. SAMPLE: 63 polyurethane foam blocks and 3 acetabular implant designs: hemiellipsoidal (Model A) and 2 models with equatorial peripheral fins (Model B with 1 level and Model C with 2 levels of fins). METHODS: 2 loading patterns-edge loading and push-out tests-were performed until failure and peak forces were recorded. Implantation behavior was visually assessed and the required seating force was assessed using a force-displacement curve. RESULTS: Model B showed significantly lower peak force than Model A in edge loading tests with standardized impaction. In the push-out test, Model A had a greater maximal force than Models B and C, with mean maximal forces of 213.7 N, 139.4 N, and 138.9 N, respectively. In the seating force test, Models B and C required a higher force for 2-mm deep implantation (362.0 N and 361.6 N, respectively) than Model A (194.4 N), and were associated with dorsal tilting of the components. CLINICAL RELEVANCE: Our results suggest that cups with a peripheral design (B, C) have less primary stability than hemiellipsoidal cups (A). Furthermore, models with peripheral fins (B, C) appeared to have incomplete seating if a higher force was not used during implantation and, therefore, the risk of malpositioning was increased. These data indicate that hemiellipsoidal cups provide the same or better initial stability and require a lower impaction force.

Comparison of hydroalcoholic rubbing and conventional chlorhexidine scrubbing for aseptic skin preparation in dogs.

OBJECTIVE: To compare preparation time, ease of application, and elimination of skin contamination of 3 skin preparation methods for asepsis. STUDY DESIGN: Experimental study. ANIMALS: Healthy dogs (n = 6) with no clinical signs of skin disease. METHODS: Three sites on each dog were randomly allocated to 1 of 3 preparation protocols for asepsis: (1) 5 scrubbings with chlorhexidine gluconate and rinsing (CHXG), (2) washing with mild soap prior to 3 rubbings with hydroalcoholic solution (soap-HAR), or (3) 3 rubbings with hydroalcoholic solution (HAR). The duration of each method of skin preparation was recorded. A Count-Tact agar plate was placed in the center of each site before, immediately after, 1 hour after, and 3 hours after antiseptic application. Plates were cultured, and colony forming units (CFU) were counted. RESULTS: Skin preparation lasted an average of 375 seconds for CHXG, 240 seconds for soap-HAR, and 190 seconds for HAR (P = .00049). Nine CFU (median) were cultured from the skin prior to preparation, with no difference between sites on any animal or for any method. Colony forming units were not detected at any time on any site in any dog after antiseptic application. CONCLUSION: Rubbing with hydroalcoholic (HA) solution was as effective as CHXG and prevented bacterial growth for at least 3 hours under these experimental conditions. Rubbing with hydroalcoholic solution was also faster and easier to perform. CLINICAL SIGNIFICANCE: Because there is currently no known resistance to HA solution, preparation of the surgical site with HAR should be considered to prevent the emergence of bacterial resistance to chlorhexidine as well as potential cross-resistances to antibiotics. Transfer to clinical animals requires additional investigation.

Prefrontal cortical activity associated with visual stimulus categorization in non-human primates measured with near-infrared spectroscopy.

In biomedical research of brain dysfunction in psychiatric disorders, utilization of animal models is essential. However, translation of findings in animal models into the realm of human clinical conditions requires reliable biomarkers that are assessed with the methods mutually employed in animal models and human patients. Near-infrared spectroscopy (NIRS) is a functional neuroimaging technique that has now been widely utilized in human basic and clinical research. However, its application to animal models has been barely conducted. In this study, we developed the method to measure neural activity in the cortex of Japanese macaques using NIRS, and examined cortical responses to presentation of a set of visual stimuli that were categorized into four different groups (flower, monkey, snake, food). Prefrontal cortical (PFC) oxy- and deoxy-hemoglobin changes were found to reliably distinguish the categories of these visual stimuli. The results suggest that cortical activity measurement with NIRS in primates can be a valuable model for identifying biomarkers associated with psychiatric disorders.