Granulation tissue in horses is a type of connective tissue that forms during the wound healing process. It is characterized by the presence of new capillaries, fibroblasts, and extracellular matrix. This tissue serves as a temporary framework over which new skin can develop, playing a significant role in the repair of tissue injuries. In equine medicine, excessive granulation tissue, commonly referred to as "proud flesh," can be a complication, particularly in wounds located on the limbs. The management and treatment of granulation tissue are important for promoting effective healing and preventing further complications. This page compiles peer-reviewed research studies and scholarly articles that explore the formation, regulation, and clinical management of granulation tissue in horses.
Theoret CL, Olutoye OO, Parnell LK, Hicks J.To compare histopathologic features of a fibroproliferative disorder in horses (exuberant granulation tissue-EGT) and people (keloid). Methods: Archival tissue samples of EGT (n = 8) and keloid (12). Methods: After automated hematoxylin and eosin, histochemical (Gomori trichrome, Verhoeff-van Gieson elastin) and immunohistochemical (vimentin, α-smooth muscle actin, CD34, CD68, CD117) stainings, tissue sections were evaluated using a semi-quantitative grading scale for presence or absence of ulceration, keloidal collagen, myofibroblasts, and elastic fibers as well as degree of inflammation, fi...
Spaas JH, Broeckx S, Van de Walle GR, Polettini M.Stem-cell therapy represents a promising strategy for the treatment of challenging pathologies, such as large, infected wounds that are unresponsive to conventional therapies. The present study describes the clinical application of peripheral blood stem cells (PBSCs) for the treatment of four adult Warmblood horses with naturally occurring wounds, which were unresponsive to conventional therapies for at least 3 months. A visual assessment was performed, and a number of wound-healing parameters (granulation tissue, crust formation and scar formation) were evaluated. In all cases, tissue overgro...
Theoret CL, Wilmink JM.Impaired wound healing represents an enormous clinical and financial problem for companion animals and humans alike. Unfortunately, most models used to study healing rely on rodents, which have significant differences in the healing and scarring process and rarely develop complications. In order to better simulate impaired healing, the model should strive to reproduce the natural processes of healing and delayed healing. Wounds on the limbs of horses display similarities to wounds in humans in their epithelialization/contraction ratio, genetic influence as well as dysregulated cytokine profile...
Link KA, Koenig JB, Silveira A, Plattner BL, Lillie BN.To compare the effect of extracorporeal shock wave therapy (ESWT) on expression of fibroblast growth factor-7 (FGF-7), transforming growth factor-β1 (TGF-β1), insulin-like growth factor-1 (IGF-1), platelet-derived growth factor-A (PDGF), and vascular endothelial growth factor-A (VEGF) in skin with surgically created skin wounds and intact skin in horses. Methods: 14 healthy horses. Methods: 8 horses were treated with ESWT at 6 locations along the neck at 36, 24, 12, 6, 2, or 1 hour prior to collection of full-thickness biopsy specimens from each location; a control specimen was collected fro...
Yuda Y, Kasashima Y, Kuwano A, Sato K, Hattori S, Arai K.Upregulation of hyaluronidase 2 (HYAL2), one of somatic hyaluronidase (HAase), was demonstrated in granulation tissue during the healing of equine superficial digital flexor tendon injuries. The activity of HAase was assessed by hyaluronan (HA)-containing gel zymography and in situ zymography using frozen sections obtained from normal and injured tendon tissues. Elevated HAase activity was identified in the extract from the tendinopathic tissues, with lower levels of the activity in normal tendons. In situ zymography using fluorescently-labeled HA demonstrated HAase activity in the granulation...
Dória RG, Freitas SH, Linardi RL, Mendonça Fde S, Arruda LP, Boabaid FM, Valadão CA.To evaluate the effects of intravenous regional limb perfusion (IRLP) administration of amphotericin B in horses to treat pythiosis after surgical excision and thermocautery. Methods: Case series. Methods: Horses (n = 12) with Pythium insidiosum infection of the distal aspect of the thoracic or pelvic limbs. Methods: After surgical excision of granulation tissue and thermocautery, 50 mg amphotericin B was administered by IRLP through a catheter placed in a superficial vein of the affected limb next to the lesion after placing a tourniquet above the injection site. The lesions and locomotor sys...
Murata D, Misumi K, Fujiki M.We hypothesized that semi-quantitative determinations of changeable blood flows in granulation and scar tissues during tendon healing could be helpful for differentiation between the acute phase rich in blood vessels and the remodeling phase with fewer vessels. Ten Thoroughbreds with injured superficial digital flexor tendon (SDFT) in a forelimb were used for evaluation of blood flows in the injured tendons of racehorses using color Doppler (CD) ultrasonography. Using longitudinal CD images, features of maximum color activities were defined. These were rhythmically blinking, tiny to small sign...
Celeste CJ, Deschesne K, Riley CB, Theoret CL.To map skin temperature kinetics, and by extension skin blood flow throughout normal or abnormal repair of full-thickness cutaneous wounds created on the horse body and limb, using infrared thermography. Methods: Experimental. Methods: Standardbreds (n = 6), aged 3-4 years. Methods: Three cutaneous wounds were created on the dorsolateral surface of each metacarpus and on the lateral thoracic wall. Thoracic skin wounds and those on 1 randomly chosen forelimb healed by second intention without a bandage, whereas contralateral limb wounds were bandaged to induce formation of exuberant granulation...
Loinaz RJ, Boutros CP, Rakestraw PC, Taylor TS.To report a laryngotomy approach for the removal of the nasal septum in adult horses. Methods: Descriptive study. Methods: Horses (n = 10). Methods: Near-total resection of the nasal septum was made using a modification of a previously reported 3-wire technique using a trephination approach and a 2-wire technique using a laryngotomy approach. Surgical time, ease of technique, complications, and outcome were recorded. At 45 days, horses were euthanatized and septal measurements made. Results: Near-total resection of the nasal septum was accomplished with both techniques without complications. I...
Hardcastle MR, Pauwels FE, Collett MG.To report morphologic findings associated with laryngoplasty failure in a horse. Methods: Clinical report. Methods: A 9-year-old Thoroughbred cross gelding. Methods: Necropsy and histopathology were performed on a horse that died peracutely during anesthetic recovery after correction of a right dorsal displacement of the ascending colon. Three weeks earlier the horse had left laryngoplasty and ventriculocordectomy. Results: Dissection of the larynx revealed that the laryngoplasty suture had pulled through the muscular process of the left arytenoid cartilage, which appeared grossly normal. Hist...
Yang G, Prestwich GD, Mann BK.The progression of wound healing is a complicated but well-known process involving many factors, yet there are few products on the market that enhance and accelerate wound healing. This is particularly problematic in veterinary medicine where multiple species must be treated and large animals heal slower, oftentimes with complicating factors such as the development of exuberant granulation tissue. In this study a crosslinked-hyaluronic-acid (HA-) based biomaterial was used to treat wounds on multiple species: rats, dogs, and horses. The base molecule, thiolated carboxymethyl HA, was first foun...
Corapi WV, Birch SM, Carlson KL, Chaffin MK, Snowden KF.CASE DESCRIPTION-A 22-year-old American Paint Horse gelding from the Gulf Coast region of Texas was evaluated for regrowth of a perirectal squamous cell carcinoma that had been surgically removed 11 months previously. CLINICAL FINDINGS-A necrotic and ulcerated mass was present below the anus. The horse had paraphimosis and was having difficulty with urination. Histologic examination of the mass revealed that it was squamous cell carcinoma, and the horse was euthanized because of the unlikelihood that the mass could be adequately resected and its close proximity to the urethra. OUTCOME-At necro...
Martins TB, Kommers GD, Trost ME, Inkelmann MA, Fighera RA, Schild AL.Twenty-one cases of pythiosis in horses (n = 10), dogs (n = 9) and cattle (n = 2) were investigated. The aetiology in all cases was confirmed by immunohistochemistry. Data related to the clinical course and outcome and localization of the lesions were obtained from pathology reports. The equine lesions consisted of fibrotic tissue with multiple, often coalescing, areas of immature granulation tissue encircling eosinophilic cores. Affected dogs had gastrointestinal and/or cutaneous lesions with either or both of a granulomatous/pyogranulomatous or necrotizing eosinophilic inflammatory reaction....
Getman LM, Davidson EJ, Ross MW, Leitch M, Richardson DW.To (1) describe the computed tomography (CT) and magnetic resonance imaging (MRI) appearance of keratomas; (2) describe a CT- or MRI-assisted partial hoof wall resection technique for removal of keratomas; and (3) evaluate the morbidity and postoperative outcome of these horses. Methods: Case series. Methods: Horses (n=10) with keratoma. Methods: Data retrieved from medical records included signalment, lameness duration and grade, physical and diagnostic evaluation findings, CT and MRI technique and findings, surgical details, histopathologic diagnosis, postoperative treatment, and complicatio...
Silveira A, Koenig JB, Arroyo LG, Trout D, Moens NM, LaMarre J, Brooks A.To determine effects of extracorporeal shock wave therapy (ESWT) on healing of wounds in the distal portion of the forelimb in horses. Methods: 6 horses. Methods: Five 6.25-cm2 superficial wounds were created over both third metacarpi of 6 horses. Forelimbs were randomly assigned to treatment (ESWT and bandage) or control (bandage only) groups. In treated limbs, each wound was treated with 625 shock wave pulses from an unfocused electrohydraulic shock wave generator. In control limbs, each wound received sham treatment. Wound appearance was recorded weekly as inflamed or healthy and scored for...
Dart AJ, Perkins NR, Dart CM, Jeffcott LB, Canfield P.To evaluate the effect of a non-occlusive dressing incorporated in a 3-layer bandage on second intention healing of wounds of the distal portion of the limb. Methods: Untreated wounds in 33 adult horses used in four studies using the same wound-healing model conducted over 5 years. Methods: Standardised, full-thickness wounds were made in the skin overlying the dorsomedial aspect of the mid-metacarpus; 17 horses were bandaged with a non-occlusive dressing covered by gauze-coated cotton wool that was compressed with adhesive tape; 16 horses were left unbandaged. Wounds were photographed weekly ...
Miragliotta V, Raphaël K, Ipiña Z, Lussier JG, Theoret CL.Wound healing in horses is complicated, particularly when wounds are on the limb. The objectives of this study were to clone equine thrombospondin II (THBS2) and secreted protein acidic and cysteine-rich (SPARC) cDNAs and to compare the spatiotemporal expression of mRNAs and proteins during repair of body and limb wounds. These molecules were targeted in view of their potential biological contribution to angiogenesis, which is exacerbated during the repair of limb wounds in horses. Cloning was achieved by screening size-selected cDNA libraries previously derived from 7-day-old wounds. Expressi...
Monteiro SO, Lepage OM, Theoret CL.To evaluate the effect of platelet-rich plasma on wounds on the distal aspect of the forelimb in horses. Methods: 6 mixed-breed 10- to 15-year-old mares. Methods: 3 wounds were created on metacarpal regions in each of 6 horses (n = 36 wounds total). Eighteen wounds were treated with platelet-rich plasma and bandaged, whereas 18 control wounds were similarly bandaged with no prior topical treatment. Decrease in wound surface area and the required number of excisions of exuberant granulation tissue were recorded until complete healing. Tissue specimens were taken from wounds at 1 week for histol...
Hanson RR.Complications of wounds and cosmetic surgery can be accurately managed with a combination of timely surgical and medical intervention to ensure the best possible outcome. The lack of soft tissue protection and a large quantity of susceptible synovial, tendon, ligament, and neurovascular structures make early and meticulous evaluation of limb wounds critical. Skin grafting is usually used following a period of open wound management and after healthy granulation tissue formation. Penetrating wounds of the abdomen or thorax have a guarded prognosis resulting from the ensuing potential for infecti...
Miragliotta V, Lefebvre-Lavoie J, Lussier JG, Theoret CL.Horses suffer from a debilitating impediment in repairing wounds located on the lower limb that leads to the development of a fibroproliferative disorder (exuberant granulation tissue). This condition is a source of wastage since it often forces retirement from competition. Treatments that resolve or prevent this condition are still lacking, maybe due to deficient knowledge of the underlying molecular mechanisms. Fibroblast-to-myofibroblast conversion is an essential step allowing contraction during wound repair and is accompanied by an increase in OB-cadherin expression. Objective: To clone e...
Miragliotta V, Lussier JG, Theoret CL.Healing of wounds located on the distal limbs of horses is often complicated by retarded epithelialization and the development of exuberant granulation tissue (proud flesh). Treatments that definitively resolve this pathological process are still unavailable. Molecular studies of the repair mechanism might contribute to the development of new therapeutic strategies. The study presented herein aimed to clone the full length cDNA and to study the spatio-temporal expression profile of mRNA and protein for LAMR1, previously attributed a role in wound epithelialization, during the repair of body an...
Miragliotta V, Lefebvre-Lavoie J, Lussier JG, Theoret CL.Wounds on horse limbs can develop exuberant granulation tissue which resembles the human keloid. Clues gained from the study of over-scarring in horses might help control fibro-proliferative disorders. Objective: The aim of the present study was to clone full-length equine ANXA2 cDNA then to study spatio-temporal expression of ANXA2 and MMP1 mRNA and protein, potential contributors to remodeling, during repair of body (normal) and limb (fibro-proliferative) wounds in an established horse wound model. Methods: Cloning of ANXA2 was achieved by screening size-selected cDNA libraries. Expression w...
Parente EJ, Tulleners EP, Southwood LL.The effectiveness and best method to perform a partial arytenoidectomy in racehorses is unclear. This study was performed to evaluate the success of and complications that can occur after a unilateral partial arytenoidectomy with primary mucosal closure in Thoroughbred racehorses. Objective: Partial arytenoidectomy is an effective surgical procedure to return Thoroughbred racehorses, afflicted by arytenoid chondropathy or a failed laryngoplasty, to preoperative levels of performance. Methods: Seventy-six Thoroughbred racehorses admitted to the New Bolton Centre between 1992 and 2006 were asses...
Holder TE, Schumacher J, Donnell RL, Rohrbach BW, Adair HS.To determine the effects of hyperbaric oxygen therapy (HBOT) on full-thickness skin grafts applied to fresh and granulating wounds of horses. Methods: 6 horses. Methods: On day 0, two 4-cm-diameter circular sections of full-thickness skin were removed from each of 2 randomly selected limbs of each horse, and two 4-cm-diameter circular skin grafts were harvested from the pectoral region. A skin graft was applied to 1 randomly selected wound on each limb, leaving the 2 nongrafted wounds to heal by second intention. On day 7, 2 grafts were harvested from the pectoral region and applied to the gra...
Nomura M, Hosaka Y, Kasashima Y, Ueda H, Takehana K, Kuwano A, Arai K.The DNA microarray analysis for matrix metalloproteinase (MMP)-related mRNA expression in equine superficial digital flexor tendinitis indicated that mRNA level of MMP-13 was apparently up-regulated in the tendinitis as compared to normal tendon. In situ hybridization also revealed that fibroblastic cells proliferated in the granulation tissue generated in the tendinitis actively expressed MMP-13 mRNA. On the other hand, in normal tendon, a few fibroblastic cells and vascular components lied in the endotenon barely expressed its mRNA, but other cellular components in the tendon bundle were not...
Dubuc V, Lepault E, Theoret CL.Wound repair in horse limbs is often complicated by excessive fibroplasia and scarring. Occlusion of the microvessels populating the granulation tissue appears to be involved in the excessive accumulation of extracellular matrix during the repair of limb wounds. This study aimed to determine whether endothelial cell hypertrophy or hyperplasia, or both, contribute to microvascular occlusion and whether the pericyte is involved in this anomaly. We created 5 wounds, each 2.5 x 2.5 cm, on both forelimbs and on the body of 6 horses. One limb was bandaged to stimulate excessive wound fibroplasia. We...
Massoni S, Vlaminck LE, Cokelaere SM, Martens AM.An 18-month-old Belgian Warmblood mare was evaluated because it had injured the outer convex aspect of the left auricle. Second intention healing of the wound area caused tissue contracture, which resulted in the tip of the ear curling backward. By use of a technique involving undermining of the skin and a flap of granulation tissue on the medial aspect of the wound area and multiple incisions of the auricular cartilage, the curling was relieved and the ear regained a more normal shape. A skin graft was applied to cover the existing wound defect in an attempt to accelerate wound healing; therm...
Lepault E, Céleste C, Doré M, Martineau D, Theoret CL.Wound repair in horse limbs is often complicated by exuberant granulation tissue, a condition characterized by excessive fibroplasia and scarring and that resembles hypertrophic scars and keloids in man. The aim of this study was to compare microvascular occlusion and apoptosis in wounds of the limb with those of the body, which heal normally. Five 6.25 cm(2) wounds were created on both forelimbs and on the body of six horses. One limb was bandaged to stimulate excessive fibroplasia. Weekly biopsies were evaluated histologically and immunohistochemically for mutant p53 protein by terminal deox...
Ducharme-Desjarlais M, Céleste CJ, Lepault E, Theoret CL.To determine the effect of a silicone dressing on the rate and quality of repair of limb wounds and compare microvascular occlusion and apoptosis in wounds treated with the silicone dressing and those treated with a conventional dressing in horses. Methods: 5 horses. Methods: Horses received two 6.25-cm2 wounds on each metacarpus. Ten wounds were treated with a silicone dressing; the other 10 were treated with a control dressing. Quality of repair and wound size were evaluated at each bandage change. Time to healing and the number of excisions of exuberant granulation tissue were recorded. Bio...
Wilmink JM, van Weeren PR.Second-intention repair is faster in ponies than in horses and faster in body wounds than in limb wounds. To a large extent, the differences between horses and ponies can be explained by differences in the local inflammatory response, which are a result of the functional capacity of leukocytes. In ponies, leukocytes produce more inflammatory mediators,resulting in better local defense, faster cellular debridement, and a faster transition to the repair phases, with more wound contraction. In horses,leukocytes produce fewer mediators, initiating a weak inflammatory response, which becomes chroni...
Wilmink JM, Stolk PW, van Weeren PR, Barneveld A.Second-intention healing of limb wounds in horses is often problematic. Solcoseryl is a protein-free, standardized dialysate/ultrafiltrate (HD) derived from calf blood, which has been shown to improve healing in both animals and humans. The efficacy of HD in the healing of deep wounds in horses and ponies was investigated. Deep wounds of 20 by 35 mm were created on both metatarsi (skin, subcutis, periosteum) and on both femoral biceps muscles (skin, subcutis, muscle) of five horses and five ponies. The wounds on one side were treated with HD, four times a week during the period that the wounds...
Bischofberger AS, Tsang AS, Horadagoda N, Dart CM, Perkins NR, Jeffcott LB, Jackson CJ, Dart AJ.To investigate the effect of activated protein C (APC) on second intention healing of distal limb wounds in horses. Methods: In this experimental study of eight Standardbred geldings, six full-thickness skin wounds (2 × 1.5 cm) were created on one metacarpus (biopsy limb) and five similar wounds were created on the contralateral metacarpus (photographed limb). Three wounds on the biopsy limb were treated topically with 190 µg APC on days 1, 3, 6 and 9, while the remaining three wounds were untreated (control). One treated and one control wound were biopsied on days 4, 7 and 11 for hi...
Holder TE, Schumacher J, Donnell RL, Rohrbach BW, Adair HS.To determine the effects of hyperbaric oxygen therapy (HBOT) on full-thickness skin grafts applied to fresh and granulating wounds of horses. Methods: 6 horses. Methods: On day 0, two 4-cm-diameter circular sections of full-thickness skin were removed from each of 2 randomly selected limbs of each horse, and two 4-cm-diameter circular skin grafts were harvested from the pectoral region. A skin graft was applied to 1 randomly selected wound on each limb, leaving the 2 nongrafted wounds to heal by second intention. On day 7, 2 grafts were harvested from the pectoral region and applied to the gra...
Mohamed FH, Abu Samra MT, Ibrahim KE, Idris SO.Cutaneous habronemiasis in 15 horses and 5 donkeys is described. The lesions were distributed in many parts of the body involving the medial canthus, shoulder and pectoral regions, knee and fetlock joints, abdominal wall and prepuce. Some animals had more than one lesion. The lesions were ulcerative and filled with soft light red granulation tissue. When curretted, the deeper layers revealed a dense fibrous tissue with calcified foci. Close examination of the lesions showed that the superficial layer of this dense fibrous tissue contained small caseated and necrotic foci. The same features pre...
Miller CB, Wilson DA, Keegan KG, Kreeger JM, Adelstein EH, Ganjam VK.To determine if there is a difference in in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. To determine the effects of a corticosteroid and monokine on in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. Methods: Growth of fibroblasts from tissues harvested from the trunk and limb were compared from horse and pony samples grown in control media and control media with triamcinolone or monokine added. Methods: Dermal and subcutaneous tissue from 22 horses and 17 ponies of various ages ...
Miller RI, Campbell RS.A survey of granulomatous and neoplastic diseases of the skin of horses of tropical north Queensland was carried out during the period 1970-1980. Of 338 horses affected, 46.4% suffered from equine fibrosarcoma (sarcoid), 30.2% from phycomycosis, 7.4% from squamous cell carcinoma, 6.8% from other tumours, 4.7% from cutaneous habronemiasis and 4.4% from exuberant granulation tissue. Most specimens were submitted during the first half of the year after the wet monsoonal season and significantly more diseases originated during the first quarter. There was minor variations with breed, age and sex s...
Murata D, Misumi K, Fujiki M.We hypothesized that semi-quantitative determinations of changeable blood flows in granulation and scar tissues during tendon healing could be helpful for differentiation between the acute phase rich in blood vessels and the remodeling phase with fewer vessels. Ten Thoroughbreds with injured superficial digital flexor tendon (SDFT) in a forelimb were used for evaluation of blood flows in the injured tendons of racehorses using color Doppler (CD) ultrasonography. Using longitudinal CD images, features of maximum color activities were defined. These were rhythmically blinking, tiny to small sign...
Leonardi F, Angelone M, Biacca C, Battaglia B, Pecorari L, Conti V, Costa GL, Ramoni R, Grolli S.Keratoma is a nonmalignant horse tumor that grows in the space between the horn of the hoof and the distal phalanx. Keratoma causes lameness in the horse, and surgical excision is the treatment of choice. Four horses underwent removal of a keratoma by complete hoof wall resection. The remaining wound was treated with platelet-rich plasma (PRP) combined with a sterile three-dimensional polylactic acid scaffold. The PRP was applied at 3, 6, 9, 12, 15, and 18 days postoperatively. The surgical site was cleaned with gauzes and swabs soaked in Ringer's lactate solution before applying PRP and the ...
Haynes PF, Snider TG, McClure JR, McClure JJ.Chronic chondritis of the arytenoid cartilage was diagnosed in 7 male Thoroughbred horses examined for obstructive upper airway disorders. The history of the cases was characterized by a 3- to 6-month progression of exercise intolerance and inspiratory dyspnea during exercise. Endoscopy revealed marked asymmetry of the rima glottidis, partial or complete inability to abduct the involved cartilage, and axial displacement of the involved arytenoid cartilage. In less severe cases, the disorder was confused with laryngeal hemiplegia. Focal elevated lesions of the involved cartilage, which were fre...
Du Cheyne C, Martens A, De Spiegelaere W.Exuberant granulation tissue (EGT) is a frequently encountered complication during second intention healing in equine distal limb wounds. Although it is still unknown what exactly triggers the formation of this tissue, previous research has revealed a persistent inflammatory response in these wounds. In this preliminary study we examined this inflammatory response in EGT-developing wounds as well as in experimental induced wounds. Immunohistological stainings were performed to detect primary inflammatory immune cells (MAC387 staining) as well as pro-resolution immune cells (CD163 staining). Ou...
Bertone AL.Second-intention healing (contraction and epithelization) is most appropriate for heavily traumatized, contaminated wounds that may have a prolonged debridement phase. Therapy during healing can promote rapid debridement and faster healing. Healing of lower limb wounds by second intention may be protracted, owing to poorer wound contraction and excessive granulation tissue production as compared with body wounds.
Atiba A, Ghazy A, Hamad MH.Cutaneous pythiosis in horses is a chronic ulcerative granulomatous disease caused by the oomycete Pythium insidiosum. Objective: The objective of the present study was to evaluate the response of cutaneous pythiosis in horses to surgical excision and topical dimethyl sulphoxide (DMSO). Methods: Thirty horses were presented clinically with pruritus, fistulae discharging serosanguineous fluid, and output kunkers in different body areas (limb, abdomen, neck, and face). The clinical diagnosis was confirmed by isolation of the causative agent and histopathology. All animals were treated by surgica...
Kobayashi A, Sugisaka M, Takehana K, Yamaguchi M, Eerdunchaolu , Iwasa EK, Abe M.This report compares the morphology and the concentrations of glycos-aminoglycans (GAGs) in an injured superficial digital flexor tendon (SDFT) of a horse with those of a normal tendon. An injured 6-year-old male Thoroughbred exhibited heat and swelling around the SDFT of the right forelimb. On histopathological examination, exuberant granulation was observed in the affected tendon, with activated tenocytes, angiogenesis, haemorrhage, and infiltration of small numbers of leucocytes. The collagen fibres were loosely packed and irregularly arranged. The diameter of control collagen fibrils was 2...
Dahlgren LA.Wound management in horses can strike fear in some and passion in others. Wounds are common injuries in horses of all descriptions and requires exceptional knowledge and care to achieve a successful outcome. New treatments to overcome the critical challenges with equine wounds are always desired: managing dehisced and/or nonhealing wounds, managing exuberant granulation tissue, and ultimately achieving a functional tissue coverage. Regenerative medicine represents a broad set of tools with great promise to manipulate the deficiencies recognized in equine wound healing and improve the outcome.
Teifke JP, Schmidt E, Traenckner CM, Bauer C.Therapy resistant swellings of the maxillary region and unilateral nasal discharge in older horses are mainly thought to be consequences of neoplasias of the oral cavity, especially of the gingiva and the teeth, or to develop from tumours of the nasal cavity. We report an unilateral swelling of the left nasal and buccal region in a 13-year-old gelding, which was accompanied by an aggressive destruction of involved osseous tissue due to a severe proliferative granulomatous inflammation. The granuloma was caused by the nematode Halicephalobus (syn. Micronema) deletrix. This nematode infection is...
Dubuc V, Lepault E, Theoret CL.Wound repair in horse limbs is often complicated by excessive fibroplasia and scarring. Occlusion of the microvessels populating the granulation tissue appears to be involved in the excessive accumulation of extracellular matrix during the repair of limb wounds. This study aimed to determine whether endothelial cell hypertrophy or hyperplasia, or both, contribute to microvascular occlusion and whether the pericyte is involved in this anomaly. We created 5 wounds, each 2.5 x 2.5 cm, on both forelimbs and on the body of 6 horses. One limb was bandaged to stimulate excessive wound fibroplasia. We...
Miragliotta V, Raphaël K, Ipiña Z, Lussier JG, Theoret CL.Wound healing in horses is complicated, particularly when wounds are on the limb. The objectives of this study were to clone equine thrombospondin II (THBS2) and secreted protein acidic and cysteine-rich (SPARC) cDNAs and to compare the spatiotemporal expression of mRNAs and proteins during repair of body and limb wounds. These molecules were targeted in view of their potential biological contribution to angiogenesis, which is exacerbated during the repair of limb wounds in horses. Cloning was achieved by screening size-selected cDNA libraries previously derived from 7-day-old wounds. Expressi...
Ragle CA, Southwood LL, Hopper SA, Buote PL.Two mares were admitted for ovariectomy of unilateral granulosa cell tumors. Both mares were ovariectomized (1 unilateral and 1 bilateral) by use of a ventral abdominal laparoscopic technique. This approach required tilting the operative table 30 degrees to elevate the pelvis and to allow observation of the ovaries. Using a single laparoscopic portal and 3 to 4 instrument portals, a triangulation technique was used. The ovarian pedicles were isolated and secured via loop ligation. The ovaries then were divided from the ligated pedicle and placed within specimen bags for extraction. The specime...
Silver IA.Wound healing is part of the normal general repair process of the body. Its efficient completion depends on many factors, some physical, eg, pH, oxygen tension and tissue tension, and some biological, eg, cell-cell interaction and feedback of extracellular matrix on to the cells which produce it. The factors which affect healing are discussed and failures and anomalies in the process described. New techniques which may improve the quality of healing in specialised tissues are explained. Recent research on wound healing has concentrated on the role of the different cell types in the process and...
Miragliotta V, Lefebvre-Lavoie J, Lussier JG, Theoret CL.Wounds on horse limbs can develop exuberant granulation tissue which resembles the human keloid. Clues gained from the study of over-scarring in horses might help control fibro-proliferative disorders. Objective: The aim of the present study was to clone full-length equine ANXA2 cDNA then to study spatio-temporal expression of ANXA2 and MMP1 mRNA and protein, potential contributors to remodeling, during repair of body (normal) and limb (fibro-proliferative) wounds in an established horse wound model. Methods: Cloning of ANXA2 was achieved by screening size-selected cDNA libraries. Expression w...
Herd RP, Donham JC.Thirty-one horses with naturally occurring summer sores were given a single IM injection of 0.2 mg of ivermectin (22,23-dihydroavermectin B1)/kg during the summer of 1980. Larvae of Draschia and/or Habronema spp were recovered from biopsy samples taken from 21 of 25 horses (84%) on the day of anthelmintic treatment. There was a marked clinical improvement in 26 horses (84%) 7 days after ivermectin was given. The typical summer sore was replaced by healthy pink granulation tissue at 7 days and this healed after 1 to 5 weeks. Biopsy samples were taken from 21 of these horses 1 to 6 weeks after t...
Couëtil LL, Gallatin LL, Blevins W, Khadra I.A 7-month-old miniature horse was referred for respiratory distress. Tracheal collapse at the level of the thoracic inlet was diagnosed. An intraluminal nitinol stent was placed with endoscopic guidance. Respiratory function was restored immediately after stent placement. The main complication observed during a 14-month follow-up period was growth of granulation tissue through the stent, which was controlled satisfactorily by electrocautery performed during endoscopy with the horse standing. Treatment of tracheal collapse with an intraluminal stent is an effective, practical, and minimally inv...
Kelleher ME, Kilcoyne I, Dechant JE, Hummer E, Kass PH, Snyder JR.To determine if application of silver sodium zirconium phosphate polyurethane semi-occlusive foam (SPF) dressing would improve measures of wound healing and decrease bacterial contamination compared with a non-adherent, absorbent dressing applied to wounds created on the distal aspect of the equine limb. Methods: Controlled randomized experimental study. Methods: Adult Quarter Horse and Thoroughbred horses (n = 5). Methods: One 6.25 cm(2) wound was created on the dorsomedial aspect of the proximal metacarpus on each forelimb. A SPF dressing was applied to 1 randomly assigned limb as a treatmen...
Booth LC.Single or multiple split-thickness autogenous skin transplants were applied to 20 limb wounds of 17 horses. The surface area of the wounds ranged from 25 to 200 sq cm. Grafts 0.635-mm thick were collected by use of an electric dermatome and were expanded on a mesh dermatome. The expanded mesh grafts were applied to wounds on 3 horses 4 days after injury. For the other 14 horses, grafts were applied after a granulation tissue bed had formed. The grafts were secured to the recipient beds with sutures and a dressing composed of a foam pad and elastic adhesive tape or with the dressing alone. Furt...
Stünzi H, Ehrensperger F, Wild P, Leemann W.A 9-year-old horse had numerous firm, painless nodules of the skin and subcutis. Moderately vascular granulation tissue with numerous uni- or multinuclear reticuloendothelial cells was in the nodules and the regional lymph nodes but not in the viscera. By using special stains and electron microscopy, widespread amyloid deposits, mainly in the cytoplasm of reticuloendothelial cells, were identified. Amyloid was probably produced within the reticuloendothelial cells, then expelled from the dying cell and deposited in the intercellular space.
Buergelt CD, Greiner EC.Fibrosing granulomas were found in the liver and occasionally on the intestinal and diaphragmatic serosae and in the lung of 11 horses submitted for necropsy. Although these granulomas were considered incidental findings in most of the horses, they had caused liver failure in 1 horse. The granulomas typically were characterized by a dense collagenous core that frequently was mineralized. The periphery contained a rim of inflammatory cells. Only in 1 of the 11 horses was there evidence of an egg shell suggestive of schistosomes. Schistosomal eggs were not detected in the feces of the horses. Th...
Carakostas MC, Moore WE, Smith JE, Johnson D.The functional capacity of the marrow granulocyte reserve (MGR) in 4 adult horses was studied, using 51Cr-labeled leukocytes. The mean increase in the peripheral granulocyte count following injections of etiocholanolone (0.3 mg/kg) was 870 granulocytes/mm3, and the mean increase following prednisolone administration (200 mg) was 5,880 granulocytes/mm3. Etiocholanolone failed to mobilize the MGR and decreased the rate of granulocyte egress from the blood. Prednisolone rapidly mobilized the MGR and markedly decreased the granulocyte specific activity during the first 3 hours after injection.
Mueller PO, Harmon BG, Hay WP, Amoroso LM.To evaluate the effect of sodium carboxymethylcellulose (SCMC) or a hyaluronate-carboxymethylcellulose membrane (HA membrane) on healing of the small intestine in horses. Methods: 18 healthy adult horses. Methods: Midline celiotomy and 2 jejunal resection-and-anastomosis surgeries were performed. In treated horses, SCMC (n = 6) or a HA membrane (6) was applied to the jejunum to cover the anastomosis. There were 6 untreated control horses. Horses were euthanatized 10 days after surgery. For each horse, 1 anastomosis was used for histologic examination, and the second was used to determine intes...
Hay WP, Tulleners E.Granulation tissue masses arising from the axial surface of the arytenoid cartilage in 25 horses were excised using a contact neodymium:yttrium aluminum garnet laser. A technique that eliminated the need for general anesthesia or laryngotomy was developed for transen-doscopic removal of the masses in standing horses. Nineteen racehorses made abnormal upper respiratory tract noises or their performance was decreased, whereas six horses not used for racing had a history of stertor (five horses) or epistaxis after nasogastric intubation (one horse). Thoroughbreds were significantly (p = .0126) ov...
Higgins AJ, Lees P, Sedgwick AD, Buick AR, Churchus R.In a two-part cross-over experiment in six ponies, an acute inflammatory reaction was generated by injecting carrageenin solution into subcutaneously-implanted tissue-cages lined with fibrovascular granulation tissue. In each part of the cross-over, half of the ponies received a novel phenylpyrazoline anti-inflammatory agent (BW540C) orally and half received a placebo treatment. BW540C inhibited platelet cyclo-oxygenase for 24 h but the reductions in exudate eicosanoid concentrations were less pronounced. A significant suppression in the rise of surface skin temperature in BW540C-treated ponie...
