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.
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...
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...
Farstvedt EG, Hendrickson DA, Dickenson CE, Spier SJ.Two horses were examined for large head wounds suspected to be the result of trauma and characterized by extensive necrosis of the skin and subcutaneous tissue, with abundant purulent exudate. Corynebacterium pseudotuberculosis was isolated from the facial wounds in both horses. Histopathologic examination revealed severe suppurative cellulitis and panniculitis with fistulous tracts and granulation tissue in 1 horse. Both horses were treated with local wound care, nonsteroidal anti-inflammatory drugs, and administration of antimicrobials. The concept of moist wound care was used in the second ...
Engelen M, Besche B, Lefay MP, Hare J, Vlaminck K.The objective of this multicentre, randomized, controlled field study was to determine the efficacy of ketanserin gel in preventing exuberant granulation tissue formation (hypergranulation) and infection in equine lower limb wounds. Horses and ponies (n = 481) with naturally occurring wounds were randomized to either topical treatment with ketanserin gel (n = 242) or a positive control (Belgium, Germany: ethacridin lactate solution, n = 120; France, United Kingdom: malic, benzoic, and salicylic acid [MBS] cream, n = 119). Treatment continued until the wound healed (success), formed hypergranul...
De Martin I, Theoret CL.To describe immunolocalization of TGF-beta receptors (RI and RII) in normal equine skin and in thoracic or limb wounds, healing normally or with exuberant granulation tissue (EGT). Methods: Group A: six wounds on one metacarpus and one midthoracic area. Group B: six wounds on both metacarpi, one of which was bandaged to stimulate EGT. Immunohistochemistry was used to detect RI and RII expression in wound margins. Methods: Eight horses, randomly assigned to one of two study groups. Methods: Neutralizing polyclonal anti-rabbit RI and RII antibodies were used to detect spatial expression of RI an...
Baudler A, Lütkefels E, Drommer W, Deegen E, Ohnesorge B.Epiglottic augmentation by transendoscopic injection of an implant material was performed on ten clinically healthy horses. In six cases bovine collagen (Zyplast) was used, in the remaining four horses the injection was done with polytetrafluorethylene (PTFE-Paste). The results of the surgery were observed endoscopically and by contrast radiography. Using the radiographs, epiglottic length and thickness were measured. For necropsy and histologic assessment the horses, three and two animals of the two groups, were euthanized at three and 12 weeks after surgery. The data obtained from the measur...
van Schie HT, Bakker EM, Jonker AM, van Weeren PR.To describe a method of computerized ultrasonographic tissue characterization that includes structures below the size limits of resolution in equine superficial digital flexor tendons. Methods: 2 damaged and 2 structurally normal superficial digital flexor tendons. Methods: Transverse ultrasonographic images were collected along the tendon long axis. Stability of echo pattern was quantified by means of variation in gray levels of each pixel in contiguous images and expressed as correlation, entropy, and waviness ratios. Results: Normal young and normal old tissues were characterized by high co...
Berry DB, Sullins KE.To determine whether povidone iodine ointment or 2 forms of silver sulfadiazine applied topically to wounds of the distal aspect of the limbs in horses affect the rate of second intention healing and to evaluate the additional influence of bandaging with these antimicrobials on granulation tissue formation. Methods: 6 healthy adult horses. Methods: Six standardized 2.5-cm2 skin wounds/horse were distributed between the dorsomedial surfaces of the metacarpi and metatarsi. One of the following 6 treatments was applied to each wound: 1% silver sulfadiazine cream with bandage, 1% silver sulfadiazi...
Schwartz AJ, Wilson DA, Keegan KG, Ganjam VK, Sun Y, Weber KT, Zhang J.To determine significant molecular and cellular factors responsible for differences in second-intention healing in thoracic and metacarpal wounds of horses. Methods: 6 adult mixed-breed horses. Methods: A full-thickness skin wound on the metacarpus and another such wound on the pectoral region were created, photographed, and measured, and tissue was harvested from these sites weekly for 4 weeks. Gene expression of type-I collagen, transforming growth factor (TGF)-beta1, matrix metalloproteinase (MMP)-1, and tissue inhibitor of metalloproteinase (TIMP)-1 were determined by quantitative in situ ...
Erkert RS, MacAllister CG, Higbee R, Moll HD, Reiners S, Crowson C, Bahr R, Bartels KE.Use of a neodymium:yttrium-aluminum-garnet laser to remove exuberant granulation tissue from the esophagus of a horse A 4-year-old Quarter Horse mare was evaluated because of recurrent esophageal obstruction. Endoscopic examination revealed a proliferative mass in the esophagus approximately 55 cm aborad to the nares. Histologic examination of biopsy specimens revealed diffuse suppurative esophagitis and granulation tissue with no evidence of neoplasia. The mass was excisedand ablated transendoscopically with a neodymium:yttrium-aluminum-garnet laser. During a follow-up examination 2 weeks aft...
Engvall EO, Egenvall A.Granulocytic ehrlichiosis is a frequently diagnosed tick-borne disease in Swedish dogs and horses. The infection is caused by a granulocytic Ehrlichia species belonging to the Ehrlichia phagocytophila genogroup. In the acute stage, the disease is mainly characterized as a febrile illness and diagnosis can be confirmed by the demonstration of ehrlichial inclusions in blood granulocytes. Seropositivity in many healthy dogs and horses indicate that the infection also can be transient without clinical signs. The infection can persist in experimentally inoculated animals for months, but to what ext...
van den Boom R, Wilmink JM, O'Kane S, Wood J, Ferguson MW.Wound healing in horses is often complicated by wound infection, exuberant granulation tissue, and hypertrophic scars, especially when wounds are located on the limbs. Wound healing in ponies is less problematic, characterized by a greater degree of wound contraction and a more intense initial inflammatory response. Because both processes are influenced by transforming growth factor-beta (TGF-beta), it was hypothesized that the better wound healing in ponies was associated with different TGF-beta profiles. A series of small wounds was created on the distal limbs and hindquarters of ponies and ...
Theoret CL, Barber SM, Moyana TN, Gordon JR.To determine whether transforming growth factor (TGF)-beta1 and -beta3 expression differs between equine limb wounds healing normally and those healing with experimentally induced exuberant granulation tissue (EGT). Methods: Six wounds were created on the lateral aspect of both metacarpi of each horse; one forelimb was untreated, and the other was bandaged to stimulate the development of EGT. Sequential wound biopsies allowed comparison of growth factor expression between the two types of wound. Methods: Four horses (2 to 4 years of age; 350 to 420 kg). Methods: Wounds were assessed grossly, h...
van Schie HT, Bakker EM, Jonker AM, van Weeren PR.To evaluate effectiveness of computerized discrimination between structure-related and non-structure-related echoes in ultrasonographic images for quantitative evaluation of tendon structural integrity in horses. Methods: 4 superficial digital flexor tendons (2 damaged tendons, 2 normal tendons). Methods: Transverse ultrasonographic images that precisely matched histologic sections were obtained in fixed steps along the long axis of each tendon. Distribution, intensity, and delineation of structure-related echoes, quantitatively expressed as the correlation ratio and steadiness ratio , were co...
Theoret CL, Barber SM, Moyana TN, Gordon JR.To map the expression of transforming growth factor (TGF)-beta(1), TGF-beta(3), and basic fibroblast growth factor (bFGF) in full-thickness skin wounds of the horse. To determine whether their expression differs between limbs and thorax, to understand the pathogenesis of exuberant granulation tissue. Methods: Six wounds were created on one lateral metacarpal area and one midthoracic area of each horse. Sequential wound biopsies allowed comparison of the temporal expression of growth factors between limb and thoracic wounds. Methods: Four 2- to 4-year-old horses. Methods: Wounds were assessed g...
Hawkins JF, Andrews-Jones L.To develop a technique for neodymium:yttrium-aluminum-garnet (Nd:YAG) laser ventriculocordectomy in standing horses and document healing in horses undergoing laser ventriculocordectomy. Methods: 6 horses between 2 and 32 years old. Methods: Under endoscopic guidance, the left laryngeal ventricle was everted with grasping forceps and excised with an Nd:YAG laser, using 60 watts of power in a noncontact fashion (6,403 to 9,197 Joules). Following removal of the ventricle, the vocal cord was photoablated. Horses were examined endoscopically 2, 7, 14, 21, 30, and 47 days after ventriculocordectomy,...
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...
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...
Steel CM, Robertson ID, Thomas J, Yovich JV.To investigate the effects on wound healing of transforming growth factor-beta 1 as a topical treatment to full-thickness, excisional wounds of the distal limb of horses. Methods: A randomised block study using four horses, each with wounds assigned to four treatment groups. Methods: Four adult Standardbred geldings. Methods: Four, 4 cm2, full-thickness wounds were created on the dorsomedial and dorsolateral aspect of the metacarpus or metatarsus of each limb of four horses, giving a total of 64 wounds. For each limb, wounds were randomly assigned to four treatment groups: no treatment (contro...
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 ...
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...
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...
Cochrane CA, Freeman KL, Knottenbelt DC.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 ce...
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...
Howard RD, Stashak TS, Baxter GM.Two 2.5-cm2 full-thickness skin wounds were created surgically over the lateral aspect of the cannon bone of each limb of 6 horses (n = 48 wounds). Dressings evaluated were a nonadherent gauze pad (group 1); a synthetic semiocclusive dressing, (group 2); equine amnion (group 3); and a synthetic fully occlusive dressing (group 4). Wounds were assessed subjectively at each dressing change, and total wound area, area of granulation tissue, and area of epithelium in each wound were determined by computerized digital analysis of photographs of the wounds. Complete healing time (wound covered by epi...
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...
Rosa MVD, Rosa M, Botteon PTL.This study aimed to evaluate the use of equine amniotic membrane (EAM), frozen indirectly using liquid nitrogen and stored between -10° and -24°C, in the treatment of equine skin lesions. Six healthy female horses, aged 3-10 years, were included in this study. EAM was collected from previously evaluated healthy parturient mares. Wounds were surgically created at the distal ends of the forelimbs. One limb was chosen for treatment, and the contralateral limb was chosen as the control. Pain sensitivity, presence of granulation tissue, secretions, and bleeding after debridement during cleaning w...
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...
Wilson DA, Adelstein EH, Keegan KG, Barrett BA, Kutz RR.To determine whether monokines produced by activated rabbit peritoneal macrophages can inhibit development of exuberant granulation tissue formation in distal limb wounds in ponies. Methods: Randomized block. Methods: 5 castrated male ponies, 2 to 6 years old and weighing 140 to 190 kg. Methods: In vitro activity of cell-free rabbit peritoneal macrophage supernatant was determined after incubation of fibroblasts from the flank and the distal portion of limbs of horses and ponies. Tritiated thymidine was then added, and after reincubation, radioactivity was measured. After creation of a 4-cm2, ...
Baird AN, Frelier PF.A Quarter Horse stallion developed an abscess over the left gluteal region after an IM injection of antihistamine. The wound healed with considerable fibrous scarring and some persistent granulation tissue. The lesion was static for 2 years before the granulation tissue went through a 6-month period of progressive enlargement. At that time, histopathologic diagnosis of squamous cell carcinoma was made from excisional biopsy. Six months after diagnosis, the horse had lost body weight and the lesional diameter had further increased, so the horse was euthanatized.
Engelen M, Besche B, Lefay MP, Hare J, Vlaminck K.The objective of this multicentre, randomized, controlled field study was to determine the efficacy of ketanserin gel in preventing exuberant granulation tissue formation (hypergranulation) and infection in equine lower limb wounds. Horses and ponies (n = 481) with naturally occurring wounds were randomized to either topical treatment with ketanserin gel (n = 242) or a positive control (Belgium, Germany: ethacridin lactate solution, n = 120; France, United Kingdom: malic, benzoic, and salicylic acid [MBS] cream, n = 119). Treatment continued until the wound healed (success), formed hypergranul...
Varasano V, Marruchella G, Petrizzi L.The healing of wounds located on the equine distal limbs can often be impaired, which can result in exuberant granulation tissue and its associated aesthetic alteration and functional failures. Although a number of therapies have been developed and assessed, the treatment of these wounds still presents challenges. This report describes the treatment of exuberant granulation tissue in a horse using an intra-lesional injection of 4% formaldehyde solution. The successful outcome of this treatment suggests that further investigations are required in order to better evaluate its efficacy, as well a...