Correlation of Dermal-Epidermal Laminar Lesions of Equine Hoof with Various Disease Conditions

Roberts, E. D.; Ochoa, Raquel; Haynes, P. F.

doi:10.1177/030098588001700601

Cited by 50 publications

(39 citation statements)

References 2 publications

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“…Decreased onychogenic substance associated with decreased synthesis, swelling, and cessation of the bundling of keratin fibers have been reported as early as 24 h o~r s .~~,~~ H yperkeratinization is notable after 10 to 20 days. 33,35,36 The laminar epithelial hyperplasia and hyperkeratinization seem to be secondary to vascular and mechanical damage. This interpretation is based on the observation that the angiopathy precedes the nonvascular changes and that both hyperplasia and hyperkeratinization are sequelae to the loss of cell-to-cell contact inhibition.…”

Section: Definition Of Temporal Phasesmentioning

confidence: 99%

The Role of Vascular Mechanisms in the Development of Acute Equine Laminitis

Hood

Grosenbaugh

Mostafa

et al. 1993

Veterinary Internal Medicne

144

110

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ACUTE LAMINITIS has long been attributed to factors or events that precede the onset of laminitis. Between 1759 and 1907 the overconsumption of grain, inflammation of the feet, suppression of perspiration (anhydrosis), excessive rest, excessive bleeding, road concussion, poor shoeing, unilateral weight bearing, sudden environmental temperature changes, prolonged standing (in the cold and aboard ships), diarrhea, and postpartum complicat i o n~' -~ were all designated as causes. Today, commonly listed etiologic factors include ingestion of large amounts of grain, cold water, lush grass, or black walnut shavings, repeated concussion, endometritis or other severe infections, colic, exhaustion, stress, drug toxicities, and endocrine dysfunctions.8-'2 At Texas A&M University (Table 1) the factors recorded as the cause presume a causal relationship between some preceding event and the acute laminitis. Logically, any event that precedes laminitis might be a cause, but etiologic validity depends on the definition of "cause" and the role that coincidence might have in the appearance of the disease.The many "causes" of laminitis have led to the belief that laminitis is a complex disorder brought about by several interacting factors. The current understanding of the pathophysiology of laminitis does not explain how these diverse factors predispose the horse to laminitis. The diagnosis of acute laminitis is based on clinical signs. Because all horses develop similar clinical signs regardless of the cause of laminitis, a common pathophysiologic mechanism is believed to be responsible.Currently, metabolic abnormalities and endotoxemia are proposed as etiologies of acute laminitis. The meta- bolic hyp~thesis'~-'~ proposes that laminitis results from derangement of metabolic processes, resulting in structural failure of laminar epithelium. The restriction of histopathologic changes to the epidermal layers and the reduced incorporation of methionine into laminar epithelium of horses with acute laminitis is consistent with decreased keratin metab01isrn.I~ In this hypothesis inflammation, mechanical collapse of the digit and vascular pathologies occur as secondary events.

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Section: Definition Of Temporal Phasesmentioning

confidence: 99%

The Role of Vascular Mechanisms in the Development of Acute Equine Laminitis

Hood

Grosenbaugh

Mostafa

et al. 1993

Veterinary Internal Medicne

144

110

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“…In the case of grafted human skin, further more, insufficient formation of BMZ proteins including type IV collagen, type VII collagen and laminin 5 cause detachment of the epidermis from the dermis [7,10]. Though such deterioration can be observed within the dermo-epidermal junction in early phase of acute laminitis, dissection of the chronically affected hoof shows existence of the hypertrophic LE between the ectopic white line tissue (lamellar wedge) and the distal phalanx [16,18,29]. This suggests that regeneration of the dermo-epidermal junction occurs due to active proliferation of the keratinocytes during the recovery phase.…”

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confidence: 99%

Unilateral Basement Membrane Zone Alteration of the Regenerated Laminar Region in Equine Chronic Laminitis

Kuwano

Ueno

Katayama

et al. 2005

The Journal of Veterinary Medical Science

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ABSTRACT. Between the laminar epidermis and the laminar dermis of laminar region (LR) in equine foot, it can be observed the basement membrane zone (BMZ), which is composed of a basement membrane and its accompaniments like the hemidesmosome and anchoring fibril. Alteration in the BMZ in equine laminitis is possibly related with not only development but also recovery outcome and recurrence of this disease. However, there is little known about the structure of the BMZ during the recovery phase of this disease. To assess the condition of the BMZ of LR affected by chronic laminitis, the tissue was examined in three cases at two weeks, four weeks and three months after the onset of laminitis, using pathological, immunohistochemical and electron microscopic techniques. Histologically in all laminitis cases, there was a regenerated laminar epidermis with proliferating keratinocytes between the Stratum medium and the dermis, but it included the undeveloped secondary epidermal laminae (ud-SELs) structure in one side of the primary epidermal laminae, especially in the part of the deep area of LR. Immunohistochemical results were positive for the anti-type IV collagen, anti-type VII collagen and anti-laminin 5 antibodies in the most BMZs. However, partial BMZs adjacent to the ud-SELs were negative for the anti-type VII collagen and anti-laminin 5 antibodies. Ultrastructurally, in the BMZ of the ud-SEL, the lamina densa and the lamina lucida were present. In contrast, the anchoring fibrils and the hemidesmosomes were either absent, or present at lower than normal levels. In conclusion, the present study indicated that the part of regenerated LR in chronic laminitis was not able to fully restore to construct the BMZ for a long time, especially in the unilateral side of laminar epidermis. It might be related with recurrence of this disease. KEY WORDS: basement membrane zone, chronic laminitis, collagen, equine, laminin 5.J. Vet. Med. Sci. 67 (7): [685][686][687][688][689][690][691] 2005 The integumental tissues of the foot are important in supporting the horse's entire body weight during static and dynamic loading conditions. If severe intractable hoof disease occurs, the horse may lose not only the ability to run, but also to stand. Laminitis is one such intractable hoof condition and has a recurrent nature. Many horses have suffered from this disease over extended periods, resulting in significant treatment costs, and therefore the equine industry has a great deal of interest in clarifying the pathogenesis and developing treatment methods [5,9,12].Anatomically, the laminar region in foot displays a complex 3-dimensional structure consisting of the primary epidermal lamina (PEL) and the secondary epidermal lamina (SEL) which interdigitate with their dermal counterparts [24]. These dermal and epidermal components are separated by the basement membrane zone (BMZ), which is composed of a basement membrane and its accompaniments like the hemidesmosome and anchoring fibril [23]. The hemidesmosome, anchoring fibril and other c...

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“…1B). pressure (Baxter;Garner et al;Roberts et al, 1980). Meanwhile, studies utilizing PAS staining correlated the fibrillary residues and the empty spaces between the SEL and the BM to pieces of fragmented BM and to the retraction of the dermal lamellae, however without the presence of fluid (Pollitt, 1996).…”

Section: Discussionmentioning

confidence: 99%

Histologic Alterations of the Basement Membrane of the Dermal and Epidermal Layers of the Hoof in Horses With Acute Laminitis

et al. 2004

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SUMMARY:The morphological characteristics of the hooves of two groups of horses were studied. The first group was comprised of six adult animals without any treatment and served as the control. The other group, comprised of seven horses, received carbohydrates overload orally. Of these, 71% developed laminitis between 36 and 48 hours after carbohydrate administration. After 48 hours of induction, the animals were sacrificed and their fore limbs and hindlimbs were removed for histologic study. Tissue sections 5 to 7 µm thick were obtained, stained with hematoxylin-eosin (H&E) or periodic acid Schiff's (PAS), and then examined by light microscopy. It was possible to identify in horses from the laminitis group, morphological and structural changes in the architecture of the primary and secondary epidermal lamellae, which were found to be sharpened and elongated with basal cells having round-shaped nuclei and also localized at the basal pole. PAS staining showed that in horses from the control group there were the presence of a basement membrane, separating and outlining the dermal and epidermal lamellae. In the laminitis group horses, there were deformation and fragmentation of the basement membrane. The utilization of PAS permitted the determination of the degenerative alterations in the basement membrane, which occurred early and coincident with the development of clinical signs of lameness.

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Correlation of Dermal-Epidermal Laminar Lesions of Equine Hoof with Various Disease Conditions

Cited by 50 publications

References 2 publications

The Role of Vascular Mechanisms in the Development of Acute Equine Laminitis

The Role of Vascular Mechanisms in the Development of Acute Equine Laminitis

Unilateral Basement Membrane Zone Alteration of the Regenerated Laminar Region in Equine Chronic Laminitis

Histologic Alterations of the Basement Membrane of the Dermal and Epidermal Layers of the Hoof in Horses With Acute Laminitis

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