OBJECTIVE To compare humoral insulin-like growth factor (IGF)-1, platelet-derived growth factor (PDGF)-BB, transforming growth factor (TGF)-β₁, and interleukin-1 receptor antagonist (IL-1Ra) concentrations in plasma and 3 types of equine autologous blood-derived preparations (ABPs). SAMPLE Blood and ABP samples from 12 horses. PROCEDURES Blood samples from each horse were processed by use of commercial systems to obtain plasma, platelet concentrate, conditioned serum, and aqueous platelet lysate. Half of the platelet concentrate samples were additionally treated with a detergent to release intracellular mediators. Humoral IGF-1, PDGF-BB, TGF-β₁, and IL-1Ra concentrations were measured with ELISAs and compared statistically. RESULTS Median IGF-1 concentration was highest in conditioned serum and detergent-treated platelet concentrate, followed by platelet concentrate and plasma; IGF-1 was not detected in platelet lysate. Mean PDGF-BB concentration was highest in platelet lysate, followed by detergent-treated platelet concentrate and conditioned serum; PDGF-BB was not detected in plasma and platelet concentrate. Median TGF-β₁ concentration was highest in detergent-treated platelet concentrate, followed by conditioned serum, platelet lysate, and platelet concentrate; TGF-β₁ was not detected in most plasma samples. Median IL-1Ra concentration was highest in platelet lysate, followed by conditioned serum; IL-1Ra was not detected in almost all plasma, detergent-treated platelet concentrate, and platelet concentrate samples. CONCLUSIONS AND CLINICAL RELEVANCE Each ABP had its own cytokine profile, which was determined by the specific processing method. Coagulation and cellular lysis strongly increased humoral concentrations of cell-derived cytokines. No ABP had the highest concentrations for all cytokines. Further studies are needed to assess clinical relevance of these findings.

Mesenchymal stromal cells (MSC) represent a promising treatment option for tendon disorders and joint diseases, primarily osteoarthritis. Since MSC are highly context-sensitive to their microenvironment, their therapeutic efficacy is influenced by their tissue-specific pathologically altered targets. These include not only cellular components, such as resident cells and invading immunocompetent cells, but also components of the tissue-characteristic extracellular matrix. Although numerous in vitro models have already shown potential MSC-related mechanisms of action in tendon and joint diseases, only a limited number reflect the disease-specific microenvironment and allow conclusions about well-directed MSC-based therapies for injured tendon and joint-associated tissues. In both injured tissue types, inflammatory processes play a pivotal pathophysiological role. In this context, MSC-mediated macrophage modulation seems to be an important mode of action across these tissues. Additional target cells of MSC applied in tendon and joint disorders include tenocytes, synoviocytes as well as other invading and resident immune cells. It remains of critical importance whether the context-sensitive interplay between MSC and tissue- and disease-specific targets results in an overall promotion or inhibition of the desired therapeutic effects. This review presents the authors’ viewpoint on disease-related targets of MSC therapeutically applied in tendon and joint diseases, focusing on the equine patient as valid animal model.

Cecocolic intussusceptions are a rare condition of acute colic in horses requiring immediate surgical intervention due to persistent uncontrollable pain and ongoing ischemic cecal necrosis. Particularly in cases where reduction of the intussusception is surgically not feasible surgical interventions such as partial typhlectomy through colotomy (partial cecal amputation) combined with or without cecal bypass techniques are described. Alternatively, surgical interventions can also be performed without partial typhlectomy via incomplete bypass ileocolostomy. Information regarding applicable techniques and outcomes base on sparse literature of single case reports or small case series. Therefore, this case series aims to add more cases treated with incomplete bypass ileocolostomy without typhlectomy to existing literature and to compare the outcome by reviewing medical records from January 2009 to March 2024 in context to literature. Five horses were surgically treated and were followed-up between 1 and 9 years. Minor short-term complications were recorded during hospitalization such as transient mild colic and febrile episodes. Long-term outcome revealed that horses received or exceed their previous level of use. By adding the hereby presented cases to published data horses treated with ileocolostomy without partial typhlectomy had a long-term survival rate of 100%. However, numbers of published cases are still low with 49 horses being included in the literature review whereof 42 recovered from surgery. The overall long-term survival rate was 53%. The added value of this study is based on the comprehensive documentation of a cohort of five horses successfully treated with an incomplete bypass procedure, demonstrating favorable long-term outcomes. Furthermore, the study advances the surgical technique by implementing the closure of mesenteric gap. The evidence for the application of the surgical technique has been strengthened.

Mouth specula with incisor bite plates shift the pressure from all teeth exclusively to the incisors in the opening phase which leads to increased forces on dental, osseous, and soft tissue structures of the horse's head. The potentially pathological character of these forces is described clinically by single reports of maxilla and mandible fractures occurring during the use of opened mouth specula. This study describes these forces on incisor teeth in horses during odontoplasty of cheek teeth under sedation. Measurements were documented using a modified “Günther” mouth speculum fitted with a force transducer along the force axis. Forces were recorded for different incisor separation distances and for dental rasping at a defined incisor separation distance. The results showed a significant difference in the median loads on the incisors at 82 mm (198.88 N), 92 mm (214.18 N), and 102 mm (293.95 N) incisor separation distance, and between active treatment with a mechanical bur (173.28 N) and no active mechanical bur (237.81 N) with maximum peaks up to 3783.60 N. Increasing bodyweight and mandible length showed a correlation with increasing forces, whereas age, gender and regularity of dental treatments did not suggest any influence on force development.