SummaryChronic orocutaneous, oronasal, or orosinus fistulae can be challenging to repair. This report describes placement of a dental bridge as a treatment for oral fistulae and outcome in two horses. A 12‐year‐old, Westphalian gelding was presented for nasal discharge because of an oromaxillary fistula after dental repulsion of the Triadan 209 4 years earlier. The second case, a 5‐year‐old Oldenburg mare was presented for an orocutaneous fistula 7 weeks after dental repulsion of the Triadan 208. Both were treated by placing an 8‐shaped cerclage wire, inserted through the rostral and caudal interdental spaces and crossing at the level of the missing tooth. Polymethylmethacrylate (PMMA) was then used to seal the fistula. No significant complications occurred during or after the surgery. In both cases clinical signs did not recur. In the first case the dental bridge is currently (5 years after the intervention) in place. In Case 2 the construction was removed after 1.5 years and the fistula had healed completely. This case report suggests that placing a dental bridge composed of cerclage wire and PMMA should be considered as an easy, noninvasive and efficient way to manage large oromaxillary or orocutaneous fistulae.

Summary Background Strangulating lesions of the small intestine involving the greater omentum (SSIGOs) have only rarely been reported. Furthermore, information pertaining to clinical descriptions, surgical findings and outcome is lacking. Objectives The objective of this study was to describe the prevalence, clinical presentation, surgical findings, postoperative outcome and risk factors associated with SSIGOs. Study design This is a retrospective case series of 32 horses with a diagnosis of SSIGOs. Methods Data from hospital records of horses identified with SSIGOs between 2005 and 2020 including signalment, clinical findings at presentation, initial laboratory results, surgical findings, surgical procedures performed and postoperative survival were analysed. The prevalence of SSIGOs was determined. SSIGO was compared with small intestinal strangulating and nonstrangulating lesions and other types of colic to identify potential risk factors among signalment data and to determine outcome, using multiple logistic regression models. Results SSIGOs were present in 2.3% (32/1413) of all horses undergoing exploratory laparotomy for colic, 4.7% of all horses with primary small intestinal lesions (32/683) and 5.6% of strangulating small intestinal lesions (32/570). Surgical findings included primary strangulation by the greater omentum with or without involvement of a lipoma‐like mass originating from the greater omentum (15/32 [47%]), adhesions involving the greater omentum leading to strangulation of the small intestine (14/32 [44%]) and small intestine incarceration through an omental rent (3/32 [9%]). The short‐term survival rate defined as survival until discharge was 53% (17/32) considering all SSIGO cases, and 85% (17/20) for SSIGO cases recovered from anaesthesia. Risk factors identified were increasing age and year of surgery. Main limitations The limitations of this study are retrospective study design and the limited number of SSIGO cases reflecting the rarity of this condition. Conclusions Numerous anatomical configurations of SSIGO exist, but clinical presentation is similar to other strangulating small intestinal lesions. Although uncommon, SSIGOs should be considered a potential cause of small intestine strangulation.

SummaryThis report outlines the diagnosis, surgical treatment and successful outcome following the treatment of a foal presented with a congenital abdominal hernia. A focal ventral abdominal swelling, enlarging since birth, starting just caudal to the intact umbilicus and extending caudally over the prepuce was observed. Once in dorsal recumbency, the hernia was found to originate from a defect of the abdominal wall in the linea alba region. A simple closed herniorrhaphy with inversion of the large peritoneal sac into the abdomen was performed. Post‐operative complications included fever with the development of an abscess at the surgical site. This was diagnosed and drained with ultrasound guidance. Based on culture and sensitivity testing of the abscess exudate, antibiotic therapy was adapted and the foal made a full recovery. A clinical examination undertaken 1 year later revealed complete healing of the linea alba. Herniation due to a muscle wall default has not been previously reported in foals. This article reviews the commonly observed causes of herniation (umbilical and inguinal hernias). However, a third type of congenital ventral body wall hernia should be considered for the differential diagnosis of swelling of the preputial area in foals.

Experimental laminitis, characterized by a failure of the dermal–epidermal interface of the foot, can be induced in horses by the oral administration of a black walnut extract (BWE). In the early phase of this severe and painful disease, an activation of neutrophil occurs, with the release of myeloperoxidase (MPO), a pro-oxidant enzyme of neutrophils, in plasma, skin, and laminar tissue. Juglone, a naphthoquinone derivative endowed with redox properties, is found in walnuts and has been incriminated in this neutrophil activation. We report for the first time the inhibitory activity of juglone on the degranulation of neutrophils induced by cytochalasin B and formyl-methionyl-leucyl-phenylalanine as monitored by the MPO release (>90% inhibition for 25 and 50 μM). Moreover, it also acts on the peroxidase activity of MPO by interacting with the intermediate “π cation radical,” as evidenced by the classical and specific immunological extraction followed by enzymatic detection (SIEFED) assays. These results are confirmed by a docking study showing the perfect positioning of juglone in the MPO enzyme active site and its interaction with one of the amino acids (Arg-239) of MPO apoprotein. By chemiluminescence and electron paramagnetic resonance techniques, we demonstrated that juglone inhibited reactive oxygen species (ROS) and superoxide anion free radical produced from phorbol myristate acetate (PMA)-activated polymorphonuclear neutrophils (PMNs). These results indicate that juglone is not the trigger for equine laminitis, at least if we focus on the modulation of neutrophil activation.

Laminitis is a pathology of the equine digit leading to a failure of the dermo-epidermal interface. Neutrophil activation is recognized as a major factor in SIRS-associated laminitis. Less is known about the role of neutrophil activation in laminitis associated with metabolic disorders. The aim of this descriptive study was to observe whether myeloperoxidase is increased in the laminae during early stage laminitis in three horses subjected to a prolonged euglycemic hyperinsulinemic clamp (pEHC). After 48 h of pEHC-treatment, horses were subjected to euthanasia. Two healthy horses are used as control. Histological sections of lamellar tissue from all horses were immunohistochemically stained for myeloperoxidase and counterstained with hematoxylin-eosin. Histopathological changes that characterize insulin-induced laminitis and increased presence of myeloperoxidase, especially in the dermal lamellae, were increased in histologic sections of pEHC-treated horses. Neutrophil myeloperoxidase release may contribute to the pathophysiology of endocrinopathic laminitis.