Outcomes of surgical treatment with patterns of bacterial culture and antimicrobial susceptibility testing in cases of cervical abscessation in dogs: 82 cases (2018-2021).

OBJECTIVE: The objective of this study was to summarize the presentation, diagnosis, and outcome for dogs surgically treated for chronic cervical abscessation following suspected or reported cervical or oropharyngeal trauma, as well as to report on culture results and antimicrobial susceptibility patterns. RESULTS: Eighty-two dogs were identified by retrospective review. Successful surgical outcome was achieved in 92.7% of dogs. Abscess recurrence was confirmed or suspected in 6/82 (7.3%) cases, and surgical intervention for abscess recurrence was performed in 4/82 (4.9%) cases. Foreign material was identified at surgery in 5/82 (6%) cases. Incisional healing complications were noted in 9/82 (10.9%) cases and required additional surgery in 5/82 (6%) cases. Twenty-three (28%) dogs had negative culture results. The results of antimicrobial sensitivity testing led to a change in antimicrobial treatment in only 9% of cases.Surgically treated cervical abscessation carries a good prognosis with a low incidence of recurrence in this cohort (in contrast to previous reports), despite low frequency of foreign body removal or identification of the underlying cause of the abscess. Excision of chronic inflammatory tissue may not be necessary for a successful outcome, contrary to previous recommendations. Multi-pathogen infections and anaerobic infections are commonly encountered.

Assessing a Novel 3D Assay System for Drug Screening against OS Metastasis.

Osteosarcoma (OS) is an aggressive mesenchymal cell tumor that carries a poor long-term prognosis. Despite definitive surgery for the primary tumor and adjuvant chemotherapy, pulmonary metastasis is common and is the primary cause of morbidity. To improve outcomes for patients, we have developed and optimized a phenotypic screen for drugs that may target OS disseminated tumor cells (DTCs) and inhibit their metastatic outbreak rather than merely screening for cytotoxic activity against proliferating cells, as is commonly conducted in conventional drug discovery approaches. We report on the validation of a previously described 3D reconstituted basement membrane extract (3D BME) model system for tumor dormancy and metastatic outgrowth adapted to clonal pairs of high and low metastatic OS cells. A post-hoc validation of the assay was possible by comparing the activity of a drug in our assay with early evidence of activity in human OS clinical trials (regorafenib and saracatinib). In this validation, we found concordance between our assay and human clinical trial experience We then explored an approved veterinary small molecule inhibitor of Janus kinase-1 (oclacitinib) as a potential drug candidate to take advantage of the high prevalence of OS in pet dogs and its translational value to humans. Despite the biological rationale, we found no evidence to support the use of oclacitinib as an antimetastatic agent in OS. The findings support our 3D BME assay as a highly efficient method to examine drugs for activity in targeting OS DTCs.

Ex vivo biomechanical comparison of the 2.4 mm uniLOCK reconstruction plate using 2.4 mm locking versus standard screws for fixation of acetabular osteotomy in dogs.

OBJECTIVE: To compare the accuracy of reduction and the biomechanical characteristics of canine acetabular osteotomies stabilized with locking versus standard screws in a locking plate. STUDY DESIGN: Ex vivo biomechanical study. SAMPLE POPULATION: Cadaveric canine hemipelves and corresponding femurs (n=10 paired). METHODS: Transverse acetabular osteotomies stabilized with 5-hole 2.4 mm uniLOCK reconstruction plates using either 2.4 mm locking monocortical or standard bicortical screw fixation (Synthes Maxillofacial). Fracture reduction was assessed directly (craniocaudal acetabular width measurements and gross observation) and indirectly (impression casts). All constructs were fatigue-tested, followed by acute destructive testing. All outcome measures (mean+/-SD) were evaluated for significance (P<.05) using paired t-tests. RESULTS: Craniocaudal acetabular diameters before and after fixation were not significantly different (21.9+/-1.2 and 21.5+/-1.2 mm; P=.45). No significant differences were observed in acetabular width differences between pre- and postoperative fixation between groups (locking -0.4+/-0.4 mm; standard -0.4+/-0.3 mm; P=.76). Grossly, there was no significant difference in the repairs and impression casts did not reveal a significant (P=.75) difference in congruency between the groups. No significant differences were found in fracture gap between groups either dorsally (locking 0.38+/-0.23 mm versus standard 0.22+/-0.05 mm; P=.30) or ventrally (locking 0.80+/-0.79 mm versus standard 0.35+/-0.13 mm; P=.23), and maximum change in amplitude dorsally (locking 0.96+/-2.15 mm versus standard 0.92+/-0.89 mm; P=.96) or ventrally (locking 2.02+/-2.93 mm versus standard 0.15+/-0.81 mm; P=.25). There were no significant differences in stiffness (locking 241+/-46 N/mm versus standard 283+/-209 N/mm; P=.64) or load to failure (locking 1077+/-950 N versus standard 811+/-248 N; P=.49). CONCLUSION: No significant differences were found between pelves stabilized with locking monocortical screw fixation or standard bicortical screw fixation with respect to joint congruity, displacement of fracture gap after cyclic loading, construct stiffness, or ultimate load to failure. CLINICAL RELEVANCE: There is no apparent advantage of locking plate fixation over standard plate fixation of 2-piece ex vivo acetabular fractures using the 2.4 mm uniLOCK reconstruction plate.

Partial 5-HT(1A) receptor agonist activity by the 5-HT(2C) receptor antagonist SB 206,553 is revealed in rats spinalized as neonates.

Modification of spinal serotonergic receptors caudal to spinal injury occurs in rats that received spinal cord transections as neonates. Evaluation of the serotonin syndrome, a group of motor stereotypies elicited by serotonergic (5-HT) agents in 5-HT-depleted animals, and open field locomotor behavior were used to assess behavioral consequences of injury and treatment. We extend these findings to show that a partial 5-HT(1A) agonist activity is revealed by the 5-HT(2C) receptor antagonist (SB 206,553) in this animal model, as measured by evaluation of serotonin syndrome behavior. Treadmill stimulation enhances this motor response, caudal to the injury, in the hindlimbs and tail. These results imply a broader modification of serotonergic receptors than previously thought and suggest a potential strategy by which serotonergic agents may enhance functional recovery following neonatal injury.