Background: The management of bleeding originating from the guttural pouch (GP) has a high success rate, but the resolution of the macroscopic inflammatory lesions in the case of mycosis (GPM) is highly variable; the resolution of neurological disorders is inconstant and challenging. Objectives: Our aim was to test the feasibility and safety of topical oxygen therapy (TOT) in horses after induction of GPM and in cases with naturally occurring disease. Study design: This study was an in vivo experimental and retrospective two-phase study. Methods: During phase 1, the pilot study, both GPs were inoculated with Aspergillus fumigatus. One GP was randomly assigned to receive one to four TOT 30 min sessions with 100% medical oxygen at 9 L/min. Follow-up endoscopic images were assessed for scoring macroscopic inflammatory lesions of the pharynx and both GPs. In phase 2, the clinical study, TOT was administered for 45 to 60 min at 15 L/min in six horses presenting with GPM. Results: In phase 1, TOT administration was easy to perform in the standing horse with no adverse effects. After more than two administrations, macroscopic inflammatory lesions decreased more quickly in size in the treated GP. In phase 2, horses were treated with TOT only (n = 1) or combined with a transarterial coil embolization (TACE) procedure (n = 5). After TOT and discharge from the hospital, nasal discharge resolved in three horses, and improvement was noted in the fourth one. Between days 2 and 10 after admission, upper respiratory tract endoscopy (URTE) indicated size reduction and alteration in the appearance of all the macroscopic inflammatory lesions. The partial or total recovery of neurological disorders (2/4 laryngeal hemiparesis, 3/5 dysphagia, 1/2 dorsal displacement of the soft palate (DDSP), and 1/1 Horner’s syndrome) was recorded. Main limitations: In phase 1, the small number of horses did not allow for statistically significant conclusions; in phase 2, clinical signs at admission varied between horses, which made comparison difficult. Conclusions: In adult horses, TOT alone or in combination with TACE is feasible and safe with a propensity to reverse the course and the progression of inflammatory lesions without additional local or systemic treatment.

Objective. To assess the clinical value and safety of the application of allogeneic equine oral mucosa mesenchymal stromal cells (OM-MSCs) to wounds. Animals. 8 healthy adult horses without front limb skin lesions or musculoskeletal disease. Procedures. Stem cells were isolated from the oral mucosa of a donor horse. Horses were subjected to the creation of eight full-thickness cutaneous wounds, two on each distal forelimb (FL) and two on both sides of the thorax (TH). Each wound was subjected to one out of four treatments: no medication (T1), hyaluronic acid- (HA-) gel containing OM-MSC (T2), HA-gel containing OM-MSC secretome (T3), and HA-gel alone (T4). Gross macroscopic evaluation and laser digital photographic documentation were regularly performed to allow wound assessment including wound surface area. Full-thickness skin punch biopsy was performed at each site before wound induction (D0, normal skin) and after complete wound healing (D62, repaired skin). Results. All wounds healed without adverse effect at D62. Distal limb wounds are slower to heal than body wounds. OM-MSC and its secretome have a positive impact on TH wound contraction. OM-MSC has a positive impact on the contraction and epithelialization of FL wounds. No significant difference between wound sites before and after treatment was noted at histological examination. Conclusion and Clinical Relevance. Using horse cells harvested from oral mucosa is a feasible technique to produce OM-MSC or its secretome. The gel produced by the combination of these biologic components with HA shows a positive impact when applied during the early stage of wound healing.

Background Capsulitis leads to the release of inflammatory mediators in the joint, causing capsular fibrosis and osteoarthritis (OA). Strain elastosonography (SE) measures the elasticity of tissue by evaluating its strain in operator-dependent deformation. The aims of the study were to assess the feasibility, repeatability, and reproducibility of SE for imaging the distal attachment of the joint capsule (DJC) of metacarpophalangeal joints in sound horses (Group S) and in horses with metacarpophalangeal OA (Group P) and to evaluate differences in the elastosonographic patterns of these horses. After a whole lameness examination, fore fetlock DJCs were assigned to Group S and Group P and were thereafter examined by two operators using SE. Qualitative (i.e., colour grading score) and semi-quantitative (i.e., elasticity index (EI) and strain ratio (SR)) methods were used to evaluate the elastograms. The inter-rater reliability (IRR), intraclass correlation coefficient (intra-CC) and interclass correlation coefficient (inter-CC) were used to compare colour grading scores and the repeatability and reproducibility of EI and SR outcomes. The same parameters were compared between groups. P < 0.05 indicated a significant finding. Results Forty-one horses were included: 11 were in Group S and 30 were in Group P (16 with bilateral OA, 8 with left OA and 6 with right OA). IRR outcomes ranged from good to excellent. For transverse and longitudinal ultrasound scans, the colour grading score of Group S was significantly higher than the metacarpophalangeal DJCs of Group P. Both Inter-CC and intra-CC were higher in Group S than in Group P, with values always > 0.8. Significative differences in EI and SR were detected between groups and between Group S and the affected limb of Group P; values were lower in Group S than in Group P. Conclusions SE can be a useful technique for evaluating DJCs, with good repeatability and reproducibility. DJCs appear softer in sound horses.