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The equine sarcoid, a fibroblastic tumor, is the most prevalent equine skin tumor and can affect all equidae. The sarcoid should be regarded as a tumor of fibroblasts. Involvement of the epidermis is a feature of most types but is not an obligatory feature. There are six visually recognizable types that correlate closely with the histology. The occult (superficial) type features alopecia, scaling, and skin thickening. The verrucose type has a prominent warty or verrucous appearance. There are two subtypes of the nodular form. Type A nodules are usually isolated individual or lobulated congregations of spherical subcutaneous masses. Type B nodules have cutaneous involvement that precludes independent movement of the overlying skin. Fibroblastic sarcoids have a fleshy fibrovascular appearance, often closely resembling granulation tissue. Type 1 fibroblastic sarcoids are pedunculated, whereas type 2 have a broad locally invasive base. The malignant sarcoid is an aggressive locally invasive form that extends widely into adjacent skin and subcutis. Mixed forms are common, and it is probably true that the large majority of sarcoid lesions have mixed components of two or more types.

Sarcoids are the most prevalent equine skin tumours and remain a therapeutic challenge due to their differing clinical morphology, local aggressive behaviour, and high recurrence following surgical treatment. In vitro, sarcoid derived fibroblasts are invasive and express matrix metalloproteinase (MMP) -1, -2 and -9. It was hypothesised that the MMPs produced by neoplastic cells play a role in both their local invasiveness and interaction with the overlying epidermis (picket fence formation). The objective of this morphological study was to investigate the local behaviour and in situ MMP expression pattern in sarcoids of different clinical types. A total of 43 surgically excised sarcoids were examined by histology, immunohistology for the expression of MMP-1, -2 and -9, and transmission electron microscopy. Regardless of the clinical type, sarcoids showed local invasion of the dermis and damage to the basement membrane in areas of interaction with the epidermis. This was associated with MMP-1 expression in both neoplastic cells and epidermis. The results suggest a link between MMP-1 expression and the local aggressiveness of sarcoids regardless of the clinical type.

Summary The intestine of neonatal mammals must be able to secrete lactase enzyme to hydrolyse lactose in its mother's milk. Failure to secrete lactase results in failure to digest lactose. This results in osmotic diarrhoea, weight loss, failure to thrive, lethargy, colic and abdominal distension. Lactose intolerance may occur secondarily to intestinal bacterial infection. Primary lactose intolerance is recognised in human infants. Here we report 2 cases of suspected primary lactose intolerance in foals. The foals responded well to oral administration of exogenous lactase enzyme.

This report describes the history, clinical, electrocardiographic and echocardiographic findings, treatment, outcome and post-mortem findings in seven horses with aorto-cardiac fistula. Affected horses included 5 stallions, one gelding and one mare; 2 each of the Thoroughbred, Arabian and Standardbred breeds and one Thoroughbred-cross with a mean +/- s.d. age of 12 +/- 4 years, range 6-18 years. The presenting signs were acute distress (four horses), exercise intolerance (two horses) and the lesion was detected during a routine examination in one horse. Five horses had monomorphic ventricular tachycardia on admission and one other had a history of this arrhythmia. Five horses had a characteristic continuous murmur loudest in the right fourth intercostal space. Echocardiography (six horses) and/or post-mortem examination (four horses) revealed the horses had aorto-cardiac fistulas arising from the right aortic sinus in all five horses in which the site was recorded. Two horses had ruptured aneurysmal dilatations of the aortic wall at this site. Fistulas extended into the right ventricle in four horses; the right atrium in two horses, the left ventricle in one horse, and five horses had dissecting tracts in the septal myocardium. Horses survived for periods ranging from 24 h to 4 years. Aorto-cardiac fistula should be considered in the differential diagnosis for horses presenting with acute distress, bounding arterial pulse, a right-sided continuous murmur and/or monomorphic ventricular tachycardia, particularly in middle-aged or older stallions. Echocardiography is the technique of choice for confirming the diagnosis and demonstrating accompanying cardiac changes.

Trunk/body wounds heal rapidly with prominent Contraction while wounds on the limb commonly fail to heal or heal slowly by centripetal epithelialization. often with insignificant contraction. Chronic exuberant granulating wounds on the limbs heal well after grafting from donor sites on the trunk. Indolent wounds are less common but may granulate significantly following moist wound-healing management. Sarcoid transformation is an increasingly important cause of healing failure. Sarcoid transformations on the trunk are commonly verrucose while those on the limb are usually aggressive and fibroblastic. The primary objective of wound management should be to encourage rapid progression from acute inflammation to repair without intervention of chronic inflammation which is a significant factor in the pathophysiology of wound healing failure. Wounds fail to heal because there is disruption of the normal delicate balance of growth factors and inflammatory mediators. Wounds should be managed in such a way as to restore the balance of healing processes without damaging any of the cells involved in healing. Resumen Las heridas localizadas en el cuerpo o tronco curan rapidamente con contraccion elevada, mientras que las de las extremidades no curan o curan lentamente por epitelizacion centripeta, a menudo con contraccion insignificante. Las heridas cronicas con tejido de granulacion exhuberantes en las extremidades curan bien despues de injertos a partir de areas del tronco. Las heridas indolentes son menos frecuentes pero pueden granular significativamente despues de un manejo humedo de la curacion de la herida. La transformacion sarcoidal es una causa cada vez mas frecuente de fracaso de la curacion. Las transformaciones sarcoidales en el tronco son generalmente de tipo verrucoso mientras que las de las extremidades son normalmente agresivas y fibroblasticas. El objetivo principal del manejo de heridas tendria que ser la estimulacion de una progresion rapida de una inflamacion aguda a la resolucion sin intervencion de inflamacion cronica, que es un factor significativo en la patofisiologia del fracaso en la curacion de heridas. Las heridas no curan porque se produce una alteracion en el fraegil equilibrio normal de factores de crecimiento y mediadores inflamatorios. Las heridas tendrian que ser manejadas de forma que se restaure el equilibrio del proceso curativo sin danar ninguna de las celulas implicadas en la curacion. [Knottenbelt, D.C. Equine wound management: are there significant differences in healing at different sites on the body? (Manejo de heridas equinas: existen diferencias significativas en la curacion en diferentes areas cutaneas?). Veterinar.): Dermatology 1997; 8: 273–290] Zusammenfassung Wunden am Rumpf heilen schnell und mit deutlicher Kontraktion, wahrend sich Wunden an den Gliedmassen oft nur geringfugig zusammenziehen und entweder gar nicht oder nur langsam vom Rande her epithelisieren. Chronische, stark wuchernde Wunden an den Gliedmassen heilen nach Gewebetransplantation vom Rumpf zufriedenstellend. Indolente Wunden sind weniger hafig, konnen aber nach benetzender Wundversorgung deutlich granulieren. Sarkoide Transformation ist ein wichtiger Grund fur Wundheilungstorungen. Sarkoide Transformationen am Rumpf sind gewohnlich warzig, jene an den Gliedmassen ublicherweise aggressiv und fibroblastisch. Das wichtigste Ziel der Wundversorgung sollte es sein, eine schnelle Entwicklung von akuter Entzundung zur Heilung zu fordern, ohne in die chronische Entzundung einzugreifen, die ein massgeblicher Faktor in der Storung der Windheilung darstellt. Der Grund fur eine nichtheilende Wunde ist eine Storung des enipfindlichen Gleichgewichts zwischen Wachstumsfaktoren und Entzundungsmediatoren. Wundversorgung soll das Gleichgewicht des Heilungsprozesses wiederherstellen, ohne Zellen zu beschadigen, die zur Wundheilung beitragen. [Knottenbelt, D.C. Equine wound management: are there significant differences in healing at different sites on the body? (Wundversorgung beim Pferd: Sind signifikante Heilungsunterschiede an verschiedenen Korperstellen vorhanden?). Veterinary Dermatology 1997; 8: 273–290] Resume Les plaies affectant le tronc cicatrisent rapidement avec une contraction proeminente tandis que les plaies des membres cicatrisent ma1 ou lentement avec une epithelialisation centripete, et souvent avec une contraction insignifiante. Les plaies presentant une granulation chronique exhuberante sur les membres cicatrisent bien apres greffe a partir d'un fragment preleve sur le tronc. Les plaies atones sonl moins frequentes, mais peuvent presenter un tissu de granulation significatif apres application de pansements humides. La transformation en sarcoide est une cause de plus en plus importante d'echec de cicatrisation. Les transformations en sarcoides sur le tronc sont frequemment verruqueuses, alors que celles localisees sur les membres sont generalement agressives et fibroblastiques. Le but premier du traitement d'une plaie est de promouvoir la progression rapide d'une inflammation aigue en cicatrisation sans passage par l'inflammation chronique qui est un facteur significatif dans la pathophysiologie de l'echec de cicatrisation des plaies. Les plaies ne cicatrisent pas parce qu'il y a un desequilibre de la balance delicate entre facteurs de croissance et mediateurs de l'inflammation. Les plaies doivent etre traitees de maniere a restaurer l'equilibre des processus de cicatrisation sans alteration des cellules impliquees dans l'inflammation. [Knottenbelt, D.C. Equine wound management: are there significant differences in healing at different sites on the body? (Traitement des plaies equines: y-a-t-il des differences significatives de cicatrisation en fonction de la topographie corporelle?). Veterinary Dermatology 1997; 8: 273–290]

Wound healing in equidae is delayed and more complicated than in other species. These complications arise from a condition known as exuberant granulation tissue formation. The lower limb of the horse is frequently slower to heal than other parts of the body and has a particular tendency to produce excess (exuberant) granulation tissue. Sarcoids are tumor-like lesions of the skin which often appear at the site of wounds. This study compared the growth characteristics of the sarcoid and granulation tissue-derived cells with normal dermal fibroblasts grown from primary cell cultures. All three cell types had distinct morphologic differences. Growth rate studies showed that the sarcoid and granulation tissue-derived cells grew at a slower rate than the normal cells. The addition of the growth factors epidermal growth factor, acidic fibroblast growth factor, and basic fibroblast growth factor selectively stimulated the replication of normal and sarcoid-derived cells but inhibited the growth of granulation tissue-derived cells. In contrast, transforming growth factor-beta was not preferentially inhibitory for the granulation tissue-derived cells. The addition of growth factors to the medium also produced distinct alterations in the morphology of the cells.

THE term ‘sarcoid’ is derived from the apparent sarcomatous appearance of the lesions as well as their tendency to recur following excision. The numbers of sarcoid (previously called 9warts9) on any individual case, their character, distribution and extent, have a major bearing on the selection of the available treatment options. Clearly, the frustrations felt by many generations of veterinary surgeons have continued up to the present time; the equine sarcoid is probably the most common cutaneous reason for euthanasia and the loss to the equine industry is considerable. Horses in which there are few localised superficial lesions are usually amenable to any of the treatment options, although inadequate application will yield a poor result with a high rate of recurrence at the site and possible extension to other sites. No effective means of treating the malevolent type of sarcoid has yet been found and interfering with this particularly aggressive form merely exacerbates the signs.

Ocular disease is a frequent finding in working horses. This study aimed to estimate the prevalence and types of ocular pathology, and explore risk factors potentially associated with disease within a population of working horses in Ethiopia. In total, 1049 horses were selected from horses attending clinics run by the Society for Protection of Animals Abroad (SPANA). Each had an ophthalmic examination conducted under field conditions using a pen-torch. All owners completed a short questionnaire. The prevalence of ocular abnormalities was 23.5 per cent (95 per cent confidence interval (CI) 18.0 per cent to 30.1 per cent) and the percentage of horses with an abnormality in at least one eye was 43 per cent (95 per cent CI 28.7 per cent to 58.4 per cent), although this varied between towns. Mild eye pathology and end-stage disease with irreversible pathology were most common. There were significantly more eye abnormalities in the right eye compared with the left, and older horses were more likely to have ocular pathology. Only 55.1 per cent of owners had noticed there was an ocular abnormality present, and only 2.2 per cent had received any previous treatment for eye disease. Only 1.9 per cent presented to the clinic because of an eye problem. There appears to be either a lack of owner awareness, or a low perception of the importance of eye disease among owners.