New pain modality for canine arthritis ???

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Cancer grades can change at reoccurrence

This study aimed to investigate grade shift in recurrent canine soft tissue sarcomas (STS) and mast cell tumors (MCT) and determine its incidence within a cohort. The study also aimed to evaluate the agreement between a single veterinary pathologist's review of primary and recurrent tumor tissues and the initial histology report. To address the issue of interobserver variability, a single board-certified pathologist performed blinded assessments and grading of all primary and recurrent tumors included in the study. This approach aimed to remove interobserver variability as a potential confounding factor. The study included cases with excisional biopsy samples of the tumors, as incisional biopsy samples can be less accurate due to tumor heterogeneity. The findings revealed that 46.7% of recurrent STS and 20.0% of recurrent MCT recurred as a different grade compared to the primary tumor. In STS cases with grade shift, 4 out of 7 recurred with a higher tumor grade, while 3 out of 7 recurred with a lower tumor grade. The only MCT case with grade shift recurred with a higher grade in the 2-tier system but no change in the 3-tier grade. These results highlight the potential for grade shift in recurrent STS and MCT in dogs, even when factors such as interobserver variability and inaccuracy of incisional samples are removed. The study also found that grade shift can involve both progression and regression of tumor grade, similar to findings in human literature. The high incidence of discrepancy in tumor grading between pathologists, particularly for STS, is another important finding. Interobserver variability in grading STS is common, and the study suggests that pathology review by an expert pathologist should be considered prior to treatment decisions. Refinement of the grading system for STS may also be necessary to reduce variability. In conclusion, this study provides evidence of grade shift in recurrent STS and MCT in dogs. It highlights the need for pathology review by an expert pathologist, as well as the potential for refinement of the grading system to reduce interobserver variability. Further studies with larger sample sizes and multiple pathologists are needed to investigate factors associated with grade shift and its prognostic significance in recurrent canine STS and MCT. 

Griffin, M. A., Hughes, K., Altwal, J., Seguin, B., & Wustefeld-Janssens, B. (2023). Grade shifts in recurrent canine soft tissue sarcomas and mast cell tumors, Journal of the American Veterinary Medical Association (published online ahead of print 2023). Retrieved Jun 2, 2023, from https://doi.org/10.2460/javma.23.01.0050 

Bottom line — Be aware that grade shift can occur especially for sarcomas

Disinfection products may lead to false positive results

The study you've presented discusses the issue of residual DNA from the bacterium Streptococcus equi (S. equi) on endoscopes, even after high-level disinfection. This is important because S. equi is the cause of strangles, a highly contagious disease in horses. Residual DNA could result in false positive qPCR test results, misdiagnosing a healthy horse as a carrier of S. equi. High-level disinfection using ortho-phthalaldehyde (OPA), accelerated hydrogen peroxide (AHP), or even water successfully eliminated live S. equi bacteria from endoscopes, but none removed all DNA. It was found that AHP resulted in a significantly lower probability of the endoscope being qPCR-positive compared to OPA and water. However, even with AHP, disinfected endoscopes were still qPCR-positive 33% of the time. There was variability in qPCR tests from day to day, which may have been due to environmental contamination, human error, and potential issues with the endoscopes used. The high rate of qPCR-positive results might be mitigated by using new disposable plastic endoscopic brushes, ensuring more thorough rinsing of the endoscopes, and perhaps exposing the endoscopes to disinfectants for longer periods of time. Interestingly, even municipal water with added chloramine rendered samples culture-negative, though it likely didn't affect residual bacterial DNA. All culture results were negative, but because qPCR test can detect even minimal DNA, it remains the gold standard for S. equi detection. AHP disinfectants seem promising due to less toxicity and lower qPCR-positive results post-disinfection, but they are more expensive and not yet recognized as compatible by all endoscope manufacturers. While OPA products are less toxic than their predecessors, they have been associated with some health concerns and may require longer exposure times to be effective. In conclusion, the main concern is the risk of false positive qPCR results due to residual bacterial DNA on endoscopes, leading to possible misdiagnosis of healthy horses as carriers of S. equi. Therefore, it is crucial to ensure endoscopes are qPCR-negative before testing. New qPCR assays, capable of distinguishing between live and dead organisms, are emerging and could be invaluable in solving this problem. 

Nadruz, V, Beard, LA, Delph-Miller, KM, Larson, RL, Bai, J, Chengappa, MM. Efficacy of high-level disinfection of endoscopes contaminated with Streptococcus equi subspecies equi with 2 different disinfectants. J Vet Intern Med. 2023; 1- 7. doi:10.1111/jvim.16740 

Bottom line — worth knowing if you’re faced with an outbreak…

Promising new OA treatment modality

The prevalence and burden of osteoarthritis (OA) are increasing, and inflammation is recognized as a common factor in all clinical phenotypes. Prostaglandin E2 (PGE2) is a key mediator of inflammation and pain in OA, and COX-2 inhibitors like celecoxib (CXB) can reduce PGE2 levels. However, systemic administration of CXB can lead to adverse effects, and intra-articular injections require frequent dosing. A biodegradable and non-toxic platform, amino acid-based polyesteramide microspheres (PEAMs), has been developed to release CXB locally for extended periods. In preclinical studies, CXB-PEAMs have been effective in reducing inflammation and pain in rat and dog OA models, without significant adverse effects. However, CXB-PEAMs were not effective in treating acute inflammation in rat models characterized by severe flares of inflammation. In conclusion, local sustained release of CXB with CXB-PEAMs is safe and effective to treat chronic OA pain in dogs suffering from natural disease and could offer a suitable strategy for long-term OA pain management. 

Sustained release of locally delivered celecoxib provides pain relief for osteoarthritis: a proof of concept in dog patients A.R. Tellegen,I. Rudnik-Jansen,L. Utomo,S. Versteeg,M. Beukers,R. Maarschalkerweerd,D. van Zuilen,N.J. van Klaveren,K. Houben,E. Teske,P.R. van Weeren,N. Karssemakers-Degen,G. Mihov,J. Thies,N. Eijkelkamp,L.B. Creemers,B.P. Meij,M.A. Tryfonidou. Osteoarthritis and Cartilageushttps://doi.org/10.1016/j.joca.2022.11.008 

Bottom line — Potential new treatment modality …

Just putting things in perspective …