American journal of veterinary research最新文献

{"title":"Cadaveric feline study revealed no significant difference in biomechanical stability following L4-L5 hemilaminectomy versus mini-hemilaminectomy.","authors":"Robin Ebeling, Christoph Thorwächter, Yury Zablotski, Andrea Meyer-Lindenberg, Frederik Volz, Matthias Kornmayer","doi":"10.2460/ajvr.26.04.0182","DOIUrl":"10.2460/ajvr.26.04.0182","url":null,"abstract":"<p><strong>Objective: </strong>To compare the biomechanical effects of hemilaminectomy (HL) and mini-hemilaminectomy (mHL) on the stability of the feline lumbar spine at L4-L5.</p><p><strong>Methods: </strong>20 cadaveric feline vertebral columns were collected from June 26, 2021, through September 15, 2022; the biomechanical testing was conducted from November 23, 2023, through March 6, 2024. Lumbar spines were screened radiographically and by CT, tested in the native state, and then randomly assigned to HL or mHL at L4-L5. Nondestructive cyclic bending in lateral bending and flexion/extension was performed with an electrodynamic testing machine. Vertebral motion was quantified with 3-D optoelectronic motion capture. Mixed-effects models compared native and postoperative states and surgical groups.</p><p><strong>Results: </strong>20 vertebral columns were eligible; 2 were used to establish the testing protocol, 4 were excluded, and 14 completed testing and were analyzed (7/group; HL and mHL). No significant differences in stability were detected between unaltered HL and unaltered mHL groups or between groups after HL versus mHL. Intragroup comparisons (unaltered HL vs HL; unaltered mHL vs mHL) showed significantly greater motion for multiple stability variables after both procedures, with more variables affected after HL than mHL.</p><p><strong>Conclusions: </strong>Both decompressive procedures decreased biomechanical stability of the feline lumbar spine relative to the native condition. Although direct differences were not detected, HL produced a more consistent pattern of increased motion than mHL.</p><p><strong>Clinical relevance: </strong>Although HL showed a more consistent pattern of increased motion, no significant differences between techniques were detected; therefore, any clinical advantage of mHL remains unproven.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-9"},"PeriodicalIF":1.6,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148987582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cardiac pacemakers in dogs: programming parameters.","authors":"Mônica Kanashiro Oyafuso, Peterson Triches Dornbusch, Juan Carlos Duque Moreno, Caio Hamamura, Marlos Gonçalves Sousa","doi":"10.2460/ajvr.26.03.0102","DOIUrl":"https://doi.org/10.2460/ajvr.26.03.0102","url":null,"abstract":"<p><strong>Objective: </strong>To report the behavior of the main parameters used in the evaluation of cardiac pacemakers (PMs) in dogs, associated complications, and survival times.</p><p><strong>Methods: </strong>This retrospective cohort study evaluated dogs that received PMs (from 2016 through 2023) at a veterinary teaching hospital. Dogs of various breeds, ages, and sexes with at least 1 baseline assessment were included. The PM parameters pacing threshold amplitude, impedance (or conductance), and estimated battery life were assessed immediately after PM insertion and at reevaluation times (≤ 7, ≤ 90, ≤ 547, ≤ 912, and ≥ 912 days). Complications and survival rates were also evaluated.</p><p><strong>Results: </strong>The median survival time of 11 dogs was 30 months. Two complications were recorded: seroma and suture dehiscence. A reduction in impedance over time was further validated by a significant Skillings-Mack test (χ2 = 12.692; P = .0054). Pacing threshold amplitude and estimated battery life did not significantly change.</p><p><strong>Conclusions: </strong>PM implantation in dogs is safe and eliminates clinical signs. A reduction in myocardial impedance (or increased conductance) is expected, but impedance assessment should consider individual baselines, observing the behavior rather than just the normal range or isolated values. Baseline pacing threshold amplitude also varies between individuals and tends to decrease over time. No significant reduction in estimated battery life was observed during the study period, probably due to high device longevity.</p><p><strong>Clinical relevance: </strong>This study provides the first data for PM parameters in dogs. The results suggest that clinical interpretation should focus on longitudinal parameter behavior relative to baseline values rather than solely on the reference range.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-7"},"PeriodicalIF":1.6,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148975532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of neuronal loss and granule cell axon reorganization in the dentate gyrus of cats with temporal lobe epilepsy-like seizures.","authors":"Kristin Baert, Caroline Majinski, Sue Osting, Elizabeth DiPaola, Paul Buckmaster, Starr Cameron","doi":"10.2460/ajvr.26.06.0275","DOIUrl":"https://doi.org/10.2460/ajvr.26.06.0275","url":null,"abstract":"<p><strong>Objective: </strong>To determine whether some cats with epilepsy and temporal lobe epilepsy (TLE)-like seizures have dentate gyrus neuropathologic changes consistent with TLE, including hilar neuron loss and mossy fiber sprouting.</p><p><strong>Methods: </strong>Postmortem hippocampal tissue from 5 cats with a history of seizures and 6 control cats was evaluated. Nissl-stained sections were used to estimate hilar neuron populations within the dentate gyrus by optical fractionator stereology. Timm-stained sections were scored by masked investigators to assess mossy fiber sprouting. Hippocampi from epileptic cats were evaluated bilaterally, and findings were compared with control cats.</p><p><strong>Results: </strong>Mean hilar neuron counts were lower in epileptic cats than controls, although this difference was not statistically significant. Two epileptic cats had hippocampal hilar neuron counts more than 2 SDs below the control mean. Mean Timm scores were higher in epileptic cats than controls, and 2 epileptic cats had mossy fiber sprouting scores more than 2 SDs above the control mean. One epileptic cat had both marked left-sided hilar neuron loss and severe mossy fiber sprouting, greatest in the left hippocampus.</p><p><strong>Conclusions: </strong>The study found that 1 epileptic cat with TLE-like seizures had dentate gyrus neuropathologic changes resembling those described in TLE in humans and other animal models.</p><p><strong>Clinical relevance: </strong>These findings support naturally occurring feline TLE as a potential clinical entity, and antemortem diagnostics should be investigated to identify these cats for advanced treatment options, such as surgical or laser ablation of the affected hippocampus.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-7"},"PeriodicalIF":1.6,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148966165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The updated 2022 Fédération Cynologique Internationale method may lead to changes in hip dysplasia grading in some dogs.","authors":"Jules Gras, Éric Goyenvalle, Mathieu Jourdain, Thomas Rousseau, Benjamin Mahieu, Éric Aguado, Olivier Gauthier, Pierre Maitre","doi":"10.2460/ajvr.26.06.0260","DOIUrl":"https://doi.org/10.2460/ajvr.26.06.0260","url":null,"abstract":"<p><strong>Objective: </strong>To compare Norberg angle (NA) measurements and hip dysplasia (HD) grades obtained from the same radiographs using the Fédération Cynologique Internationale (FCI) 2022 (FCI22) and FCI 2006 methods (FCI06).</p><p><strong>Methods: </strong>This retrospective observational study included radiographs submitted for canine HD screening from March 17, 2023, through September 27, 2024. Radiographs meeting FCI quality standards were evaluated under both methods, with NA measurements and HD grades recorded accordingly. Grade changes were classified as upgraded, downgraded, or unchanged.</p><p><strong>Results: </strong>Radiographs from 1,020 Australian Shepherds and 298 Boxers were reviewed. The mean Norberg angle measured according to the 2022 method (NA22) was 0.7° lower than that measured according to the 2006 method (NA06). Overall, 1,801 of 2,636 hips (68.3%) retained the same HD grade with the FCI22. In Australian Shepherds, 350 of 2,040 hips (17.2%) were upgraded, and 257 of 2,040 hips (12.6%) were downgraded. In Boxers, 53 of 596 hips (8.9%) were upgraded, and 175 of 596 hips (29.4%) were downgraded. Reclassification occurred primarily among hips initially graded D in 2006 (D06), with 286 of 347 hips (82.4%) reclassified.</p><p><strong>Conclusions: </strong>Differences between NA22 and NA06 had limited impact on HD grading except for hips with near-threshold NA values. The FCI22 kept most HD grades unchanged. Across both breeds, upgrades occurred primarily among grade D hips. Breed differences in grade changes may reflect interbreed anatomical differences.</p><p><strong>Clinical relevance: </strong>The FCI22 method is unlikely to substantially alter HD grades in these 2 breeds. Borderline hips and breed-specific grading patterns may affect individual screening outcomes.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-8"},"PeriodicalIF":1.6,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148966186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modified tibial plateau-leveling osteotomy using a precontoured plate achieves single-stage correction with favorable clinical outcomes in small-breed dogs.","authors":"Hyun-Kyu Lee, Tae-Wan Kwon, Byung-Jae Kang","doi":"10.2460/ajvr.26.07.0314","DOIUrl":"https://doi.org/10.2460/ajvr.26.07.0314","url":null,"abstract":"<p><strong>Objective: </strong>To evaluate outcomes of modified tibial plateau-leveling osteotomy (TPLO) using a precontoured plate in small-breed dogs with concurrent cranial cruciate ligament (CrCL) rupture and medial patellar luxation (MPL) compared with conventional TPLO.</p><p><strong>Methods: </strong>Medical records from March 2023 to March 2026 were retrospectively reviewed for dogs treated with TPLO using a 1.5/2.0 locking plate. Stifles were assigned to the modified TPLO group when concurrent MPL was corrected using a precontoured plate or to the conventional TPLO group without MPL correction. Radiographic measurements including bone healing time and clinical outcomes based on the orthopedic assessment score and kinetic variables were evaluated.</p><p><strong>Results: </strong>Seventeen and 15 stifles were included in the conventional and modified TPLO groups, respectively. Tibial plateau angle decreased significantly in both groups. Medial patellar luxation was corrected in all modified TPLO cases; asymptomatic reluxation occurred in 2 dogs, but no complications required surgical intervention. Median bone healing time was 84 days (57 to 233) and 71 days (44 to 194) in conventional and modified TPLO groups, respectively, with no significant intergroup difference. Orthopedic assessment score and kinetic variables improved from baseline with no significant difference between groups.</p><p><strong>Conclusions: </strong>Modified TPLO using a precontoured plate achieved single-stage correction of concurrent CrCL rupture and MPL in small-breed dogs. Despite proximal tibial medial translation, no significant intergroup differences were detected in evaluation of postoperative radiographic, veterinarian-assessed, or objective gait analysis during follow-up.</p><p><strong>Clinical relevance: </strong>Modified TPLO using a precontoured plate may provide a feasible surgical option for concurrent CrCL rupture and MPL in small-breed dogs.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-9"},"PeriodicalIF":1.6,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148966210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic resonance imaging identifies prognostic features in dogs and cats with ischemic cerebrovascular accidents.","authors":"Jean Desbordes, Abdelghani Sifouane, Yannick Ruel, Albert Agoulon, Stella Papageorgiou, Kirsten Gnirs, David Grevent, Nathalie Boddaert, Hugues Gaillot","doi":"10.2460/ajvr.26.06.0268","DOIUrl":"https://doi.org/10.2460/ajvr.26.06.0268","url":null,"abstract":"<p><strong>Objective: </strong>To characterize MRI findings, including arterial spin labeling (ASL) perfusion features, in dogs and cats with ischemic cerebrovascular accidents (ICVAs) and to identify prognostic factors.</p><p><strong>Methods: </strong>Retrospective, single-center observational study of dogs and cats presenting with acute, nonprogressive brain dysfunction from 2018 through 2024, with MRI findings consistent with ICVA and available ASL perfusion imaging. Ischemic cerebrovascular accidents subtypes; MRI findings, including ASL perfusion characteristics; and outcomes were analyzed.</p><p><strong>Results: </strong>63 animals (47 dogs and 16 cats) were included. A novel complete territorial ICVA subtype, involving either an entire middle cerebral artery territory or an entire cerebellar hemisphere, was identified in 8 of 63 animals (12.7%) and commonly associated with moderate-to-severe mass effect. All nonlacunar infarcts exhibited focal ASL hypoperfusion, whereas lacunar infarcts showed no detectable perfusion abnormalities. Ischemic penumbra was identified in only 2 of 19 animals (10.5%) with nonlacunar infarcts imaged within 24 hours of onset. Complete territorial ICVAs with moderate-to-severe mass effect were classified as malignant ICVAs because this pattern was strongly associated with early mortality (OR, 400; 95% CI, 14.5 to 11,039).</p><p><strong>Conclusions: </strong>These findings expand the recognized spectrum of ICVA in dogs and cats and indicate that infarct extent and mass effect are important markers of disease severity and early outcome. ASL perfusion can demonstrate hypoperfusion in nonlacunar ICVAs but has limited ability to identify potentially salvageable ischemic tissue.</p><p><strong>Clinical relevance: </strong>Recognition of complete territorial and malignant ICVAs may improve early prognostic assessment and inform clinical decision-making in dogs and cats with ICVA.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-11"},"PeriodicalIF":1.6,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148944137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Guidelines for the prioritization of adoptable shelter animals for sterilization to reduce average length of stay: a mathematical model.","authors":"Michael Loizos Mavrovouniotis","doi":"10.2460/ajvr.26.06.0270","DOIUrl":"https://doi.org/10.2460/ajvr.26.06.0270","url":null,"abstract":"<p><strong>Objective: </strong>To determine the prioritization of shelter animals for sterilization surgery based on length of stay (LOS), when animals must be sterilized before adoption but capacity constraints necessitate deferral.</p><p><strong>Methods: </strong>This mathematical modeling study defines optimal policy as prioritizing animals whose deferral would have the largest adverse impact on LOS. It derives closed-form expressions for that impact dependent on each animal's baseline (sterilized) expected LOS, adopter aversion to waiting for surgery, and deferral duration.</p><p><strong>Results: </strong>Analytical derivation shows the LOS impact is monotonic in each animal's baseline LOS. Monotonicity direction depends on a parameter V measuring adoption opportunity within the deferral window. The parameter V equals the fraction of adopters willing to commit before sterilization multiplied by the duration of the deferral. An existing guideline prioritizing fast-track animals, which have shorter baseline LOS, is confirmed when V > 1. This effect is concentrated at low to medium baseline LOS (but flattens above 20 days). When V = 1, the impact becomes independent of the animal's baseline LOS. When V < 1, animals with longer baseline LOS should be prioritized, but this preference is weak.</p><p><strong>Conclusions: </strong>In practice, shelters should prioritize animals with lower baseline LOS when V substantially exceeds 1, and there are candidates with low to medium LOS. In the remaining cases, the effect is weak (including V < 1 when the direction changes), and shelters may rely on other considerations.</p><p><strong>Clinical relevance: </strong>These findings provide a quantitative basis for allocating limited shelter resources toward reducing LOS and shelter census, in the interest of maintaining and improving care.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-9"},"PeriodicalIF":1.6,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arthroscopic approach and intra-articular anatomy of the dromedary camel (Camelus dromedarius) metacarpophalangeal joint.","authors":"Morgane A Schambourg, Hatem A El Meligy, Sylvain Nichols, Julien Olive","doi":"10.2460/ajvr.26.06.0241","DOIUrl":"https://doi.org/10.2460/ajvr.26.06.0241","url":null,"abstract":"<p><strong>Objective: </strong>To define the metacarpophalangeal joint (MCPJ) anatomy and its relationships to surrounding structures, relevant to dorsal and palmar arthroscopic approaches, and guide technique development in the camel (Camelus dromedarius).</p><p><strong>Methods: </strong>Dromedary camel cadaver front limbs were collected from either a slaughterhouse or euthanized individuals for this experimental ex vivo study, excluding those with clinically visible MCPJ pathology. Computed tomography and MRI were conducted on 2 MCPJs to determine relationships with surrounding structures and the extent of their synovial cavity following distension. Dorsal and palmar arthroscopic approaches were performed on 16 MCPJs, after which dissection objectified iatrogenic damage.</p><p><strong>Results: </strong>8 front limbs were collected. Advanced imaging allowed depiction of all joint particularities, including the prominent dorsal synovial plica, the dorsally flattened metacarpal condyles, and the complete separation of the adjacent MCPJs. Arthroscopic exploration of the dorsal aspect of the MCPJ allowed examination of the articular cartilage (including weight-bearing surfaces) of both distal metacarpus and proximal P1 and access to those areas. Palmar exploration and instrument access to the axial aspect were limited by the available space and shape of the articular surfaces of the sesamoid bone and the sagittal ridge of metacarpus.</p><p><strong>Conclusions: </strong>MRI and CT studies improved surgical planning and helped with prediction of the limitations of palmar arthroscopic exploration, including the distal aspect of the joint space and access to the axial sesamoid bone.</p><p><strong>Clinical relevance: </strong>Diagnostic and therapeutic arthroscopy of the MCPJ should advance the understanding and treatment of conditions of this joint in the camel.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-8"},"PeriodicalIF":1.6,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distance and concentration significantly influence indocyanine green fluorescence intensity in near-infrared endoscopic viewing modes: an in vitro blotting paper model.","authors":"Nontalie Kaschark, Sarah J Marvel, Pedro Boscan, Eric Monnet","doi":"10.2460/ajvr.26.02.0076","DOIUrl":"https://doi.org/10.2460/ajvr.26.02.0076","url":null,"abstract":"<p><strong>Objective: </strong>To evaluate the effects of indocyanine green (ICG) concentration, camera-to-target distance, and their interaction on fluorescence intensity (FI) using a near-infrared (NIR) endoscopic system in dark and overlay modes.</p><p><strong>Methods: </strong>7 ICG dilutions (0 to 2.5 mg/mL) were applied to white blotting paper. Images were captured using a 0°, 10-mm NIR endoscopic system at distances of 2, 5, and 10 cm in dark mode (monochromic NIR signal) and overlay mode (NIR signal superimposed on white light). Fluorescence intensity (dark mode) and light intensity (LI; overlay mode) were quantified using ImageJ software (version 1.54; NIH). Data were analyzed via ANOVA and bivariate linear regression.</p><p><strong>Results: </strong>In dark mode, distance significantly influenced FI, with maximum intensity at 2 cm and no signal at 10 cm. Indocyanine green concentration also significantly affected FI, with the highest FI at 0.0156 mg/mL; concentrations above 0.625 mg/mL showed quenching. In overlay mode, LI was maximized at 5 cm and decreased significantly at 2 cm. Concentration had an inverse effect in overlay mode, where 0 mg/mL (control) yielded the highest LI. Dark mode FI and overlay mode LI were significantly inversely correlated.</p><p><strong>Conclusions: </strong>In this experimental model, fluorescence and light intensities depend on camera distance and ICG concentration. Signal loss occurs at greater distances, and quenching effects are prominent in specific viewing modes.</p><p><strong>Clinical relevance: </strong>In this in vitro model, ICG concentration, camera-to-target distance, and viewing mode influenced fluorescence and light intensity. These findings support standardization of image acquisition and future in vivo validation.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-6"},"PeriodicalIF":1.6,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148918143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-cell sequencing reveals synovial fluid γδ T-cell expansion in equine experimental osteoarthritis.","authors":"Dylan Ammons, Lyndah Chow, Laurie Goodrich, Myra Barrett, Brad Nelson, Renata Impastato, Jason W Stoneback, Steven Dow, Lynn M Pezzanite","doi":"10.2460/ajvr.26.06.0272","DOIUrl":"https://doi.org/10.2460/ajvr.26.06.0272","url":null,"abstract":"<p><strong>Objective: </strong>Define temporal cellular changes following joint injury using single-cell RNA sequencing in experimental equine posttraumatic osteoarthritis (PTOA).</p><p><strong>Methods: </strong>PTOA was induced in 4 Quarter Horses (3 to 5 years) via carpal osteochondral fragmentation and high-speed treadmill exercise. Synovial fluid (SF) cells and synovium were sampled over 18 weeks (November 2023 to April 2024). Single-cell suspensions were processed (10x Genomics Chromium iX), then aligned to the equine genome (Cell Ranger). Downstream analysis was completed in the R Seurat package. Differential gene expression (log2[fold change] > 1; P < .05) and differential abundance analyses were performed (P < .1).</p><p><strong>Results: </strong>Cartilage injury had a modest impact on gene expression changes and cell abundance shifts in SF. Integrated analysis of 90,323 SF cells across 4 time points revealed 9 distinct cell types, primarily T cells (73 ± 19%) followed by myeloid cells (20 ± 13%). Subcluster analysis of T cells revealed 9 transcriptomically distinct subtypes (3 CD8, 2 CD4, 3 γδ, and 1 cycling). Differential abundance analyses of temporal changes identified increased γδ T and decreased CD4+ T-cell subsets in joints over time. Expanded populations of IL-23 receptor-positive γδ T cells exhibited increased T-helper 17 signatures.</p><p><strong>Conclusions: </strong>IL-23 receptor-positive γδ T-cell expansion, associated with joint inflammation, occurred in PTOA. Limitations include small sample size and individual heterogeneity; further investigation over extended timeframe is necessary to confirm whether later stages of the experimental model reflect natural chronic OA.</p><p><strong>Clinical relevance: </strong>Cellular immunotherapy targeting γδ T cells and IL-23/IL-17 blockade may warrant investigation to mitigate equine OA progression.</p>","PeriodicalId":7754,"journal":{"name":"American journal of veterinary research","volume":" ","pages":"1-15"},"PeriodicalIF":1.6,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148918156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}