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- Author or Editor: M. C. Roberts x
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SUMMARY
The connective tissue structures commonly referred to as the periorbita, orbital septum, muscular fasciae, and vagina bulbi or collectively, as the orbital fasciae were dissected then illustrated and described.
Two sheets (layers) of the periorbita (endorbita) were found in our dogs. The periorbita should be renamed endorbita because of its anatomic relations. The periorbita did not always fuse with the periosteum of frontal and sphenoid bones. Rather, the periorbita and the periosteum were often distinct and separate; only medioventrally did several fibrous bands unite the superficial sheet of the endorbita with the periosteum. Two layers of the endorbita fused with the periosteum of the margin of the bony orbit and with the orbital ligament.
The muscular fasciae were divided into 3 layers. The superficial layer extended caudally from the orbital septum, was thick, and was pierced by arteries, veins, and nerves. The middle layer was attached to the sclerocorneal junction and, at the temporal canthus of the eye, was divided into superficial and deep sheets. The deep portion was attached to the lateral angle of the third eyelid, similar to a strong ligament. The deep layer of the muscular fasciae extended caudally from the sclerocorneal junction in intimate contact with recti and oblique muscles of the eyeball. The deep portion of the deep muscular fascia covered the deep surface of all recti muscles and separated them from the retractor bulbi muscle. Intermuscular septa were observed between middle and deep muscular fascia layers. The body of the third eyelid was located between superficial and middle muscular fascia layers and was fixed ventrally to the lateral angle of the eye by the deep sheet of the middle muscular fascia.
Abstract
Objective—To determine history; clinical, radiographic, ultrasonographic, and scintigraphic abnormalities; treatment; and outcome in horses with tuber coxae fractures and to describe a useful technique for obtaining a dorsomedial-ventrolateral 50° oblique radiographic view of the tuber coxa of the ilium in standing horses.
Design—Retrospective case series.
Animals—29 horses with fractures of tuber coxa.
Procedures—Data collected from medical records included signalment; history; horse use; severity and duration of lameness; radiographic, ultrasonographic, and scintigraphic findings; treatment; and outcome.
Results—All horses had a traumatic event leading to acute, unilateral hind limb lameness. Eighteen horses had a more severe lameness at the walk than at the trot; 22 of 29 horses had an abnormal gait with the hind limbs tracking to 1 side of the forelimbs. Twenty-four of 29 horses had palpable and visual asymmetry between the affected and unaffected tuber coxae. Twenty horses had radiography performed while sedated but standing, and fractures were reliably identified on the dorsomedial-ventrolateral 50° oblique radiographic views. Twenty-seven (27/29 [93%]) horses returned to athletic use. Horses sustaining partial fractures of the caudal aspect of tuber coxae returned to previous use significantly earlier (mean, 3 months), compared with horses with complete tuber coxae fractures (6.5 months).
Conclusions and Clinical Relevance—Horses with tuber coxae fractures returned to athletic soundness following extended periods of rest. Findings emphasized the need for obtaining a dorsomedial-ventrolateral 50° oblique radiographic view of the tuber coxa of the ilium in horses suspected of sustaining injury to this region.
Abstract
Objective—To ultrasonographically evaluate hemodynamics in the abdominal aorta (AAo) and splanchnic vessels in dogs with experimentally induced normovolemic anemia.
Animals—11 healthy Beagles.
Procedure—The AAo, cranial mesenteric artery (CMA), celiac artery (CA), hilar splenic artery (HSA), and main portal vein (MPV) were evaluated in conscious dogs immediately before and after experimental induction of severe normovolemic anemia (Hct, 16%) and during recovery from moderate and mild anemia (Hct, 26% and 34%, respectively). Peak systolic velocity (PSV) or peak velocity (PV), time-averaged mean velocity (TAVmean), pulsatility index (PI), resistive index (RI), blood flow, congestion index (CI), and heart rate (HR) were recorded. Results were compared for anemic and control states.
Results—Severe anemia caused significant increases in HR (25% to 70%), PSV (AAo, 45.8%; CMA, 56.1%; and CA, 41.9%), PV (MPV, 84.2%), and TAVmean (AAo, 69.4%, CMA, 64.3%; CA, 29.7%; and MPV, 76.9%) and significant decreases in PI (AAo, 26.1%; HSA, 19.3%) and CI (MPV, 45.2%). There was no significant change in PI of the CMA or CA, portal blood flow, or RI of any artery. Significantly higher TAVmean persisted in all vessels during moderate anemia, but higher PSV persisted only in the CMA; PI (CMA and CA) and RI (CA) decreased significantly, but portal blood flow increased significantly. Significant increase in TAVmean (AAo and CMA) persisted during mild anemia, and PI (AAo, CMA, and HSA) but RI (CMA) were significantly lower.
Conclusions and Clinical Relevance—Doppler ultrasonography revealed hyperdynamic circulation in the AAo and splanchnic vessels in dogs with experimentally induced normovolemic anemia. (Am J Vet Res 2005;66:187–195)
SUMMARY
Oral keratinocytes from dogs were cultured on either collagen gels or artificial matrices at the air-liquid interface, and the expression of keratinocyte antigens and basement membrane components was determined, using various monoclonal and polyclonal antibodies. Keratinocytes grown on collagen gels expressed pemphigus vulgaris, pemphigus foliaceous, and bullous pemphigoid antigens. Diffuse, suprabasal, and superficial keratinocyte membrane differentiation antigens identified by various monoclonal antibodies also were expressed in a pattern identical to that observed in the native tissue. Laminin and type-IV collagen were deposited at the keratinocyte-collagen interface in a patchy distribution. When synthetic matrices were used, the oral keratinocytes differentiated, but to a lesser extent than cells grown on collagen gels. Antigen expression for cells grown on synthetic matrices was similar to that for cells on collagen, except for failure of the keratinocytes on synthetic membranes to express superficial cell antigens and pemphigus foliaceous antigens.
Abstract
Equine fungal keratitis represents a substantial portion of keratitis cases in horses, with fungal involvement identified in approximately half of all infectious keratitis cases. Despite its prevalence, more comprehensive retrospective analyses are needed to better understand this condition. Outcomes vary, with approximately two-thirds of cases achieving complete healing with retained vision, although enucleation is often necessary. Predominant pathogens include Aspergillus and Fusarium, with yeast reported in a minority of cases. Resistance to common antifungal agents among filamentous fungi poses a significant challenge. Advances in diagnostics, including repeat culture and antifungal susceptibility testing, as well as the incorporation of PCR technology, hold promise for improving detection and guiding treatment decisions. Newer antifungals, combination therapies, and innovative modalities such as photodynamic therapy offer hope for improved outcomes. Continued research efforts are essential to further elucidate the epidemiology, pathogenesis, and optimal management strategies for this condition.
Abstract
Objective—To determine the pulmonary epithelial lining fluid (ELF) concentrations and degree of oxidation of ascorbic acid in horses affected by recurrent airway obstruction (RAO) in the presence and absence of neutrophilic airway inflammation.
Animals—6 RAO-affected horses and 8 healthy control horses.
Procedure—Nonenzymatic antioxidant concentrations were determined in RBC, plasma, and ELF samples of control horses and RAO-affected horses in the presence and absence of airway inflammation.
Results—ELF ascorbic acid concentration was decreased in RAO-affected horses with airway inflammation (median, 0.06 mmol/L; 25th and 75th percentiles, 0.0 and 0.4 mmol/L), compared with RAOaffected horses without airway inflammation (1.0 mmol/L; 0.7 and 1.5 mmol/L) and control horses (2.2 mmol/L; 1.4 and 2.2 mmol/L). Epithelial lining fluid ascorbic acid remained significantly lower in RAOaffected horses without airway inflammation than in control horses. Moreover, the ELF ascorbic acid redox ratio (ie, ratio of the concentrations of dehydroascorbate to total ascorbic acid) was higher in RAO-affected horses with airway inflammation (median, 0.85; 25th and 75th percentiles, 0.25 and 1.00), compared with RAOaffected horses without airway inflammation (0.04; 0.02 and 0.22). The number of neutrophils in bronchoalveolar lavage fluid was inversely related to the ELF ascorbic acid concentration ( r = –0.81) and positively correlated with the ascorbic acid redox ratio ( r= 0.65).
Conclusions and Clinical Relevance—Neutrophilic inflammation in horses affected by RAO is associated with a reduction in the ELF ascorbic acid pool. Nutritional supplementation with ascorbic acid derivatives in horses affected by RAO is an area for further investigation. ( Am J Vet Res2004;65:80–87)
Abstract
Objective—To examine articular cartilage of the distal interphalangeal (DIP) joint and distal sesamoidean impar ligament (DSIL) as well as the deep digital flexor tendon (DDFT) for adaptive responses to contact stress.
Sample Population—Specimens from 21 horses.
Procedure—Pressure-sensitive film was inserted between articular surfaces of the DIP joint. The digit was subjected to a load. Finite element models (FEM) were developed from the data. The navicular bone, distal phalanx, and distal attachments of the DSIL and DDFT were examined histologically.
Results—Analysis of pressure-sensitive film revealed significant increases in contact area and contact load at dorsiflexion in the joints between the distal phalanx and navicular bone and between the middle phalanx and navicular bone. The FEM results revealed compressive and shear stresses. Histologic evaluation revealed loss of proteoglycans in articular cartilage from older horses (7 to 27 years old). Tidemark advancement (up to 14 tidemarks) was observed in articular cartilage between the distal phalanx and navicular bone in older clinically normal horses. In 2 horses with navicular syndrome, more tidemarks were evident. Clinically normal horses had a progressive increase in proteoglycans in the DSIL and DDFT.
Conclusions and Clinical Relevance—Load on the navicular bone and associated joints was highest during dorsiflexion. This increased load may be responsible for microscopic changes of tidemark advancement and proteoglycan depletion in the articular cartilage and of proteoglycan production in the DSIL and DDFT. Such microscopic changes may represent adaptive responses to stresses that may progress and contribute to lameness. (Am J Vet Res 2001;62:414–424)
