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.
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...
Dinev D, Dzhurov A.An experiment in comparative developmental aspect was carried out with 5 horses and 5 cattle having a total of 60 skin and muscular wounds. Light microscopic studies on hematoxylin-eosin stained preparations revealed that the dystrophic changes in the underlying tissues were more strongly manifested in horses. This had to be taken into consideration in the surgical treatment of wounds with this animal species. The basic differences comprised the better manifested leukocytic reaction in horses and the more strongly expressed processes of growth and differentiation on the part of the connective ...
Vos JH, van der Gaag I, van Dijk JE, Wouda W.Seven cases of cutaneous haemangiomas in young horses are described, characterized by scattered, well demarcated but unencapsulated lobules, consisting of capillary sized vascular structures, separated by strands of fibrous tissue. In one case, a more cellular variant was distinguished with minor vasoformative capacity. The morphological features of these haemangiomas are compatible with bovine cutaneous angiomatosis and human granuloma pyogenicum. The lesions are considered to be vascular tumours rather than hamartomas or granulation tissue and "lobular capillary haemangioma" is suggested to ...
Webbon PM.A series of experimental tendon biopsies is described. Three biopsies were taken from the lateral digital extensor tendon (LDET) and three from the superficial flexor tendon (SFT). The LDET biopsies resulted in little discomfort whereas the SFT biopsies led to temporary lameness. The tendons were examined histologically up to 99 days after the biopsies were removed. In all of the tendons the defect filled with granulation tissue which subsequently became organised as a longitudinally orientated collagenous scar tissue. In this small series of biopsies the histological effects of the biopsy per...
Embertson RM, Hodge RJ, Vachon AM.A 13-year-old, 370-kg, Appaloosa gelding with mild colic of 4 days' duration was found to have a near circumferential retroperitoneal rectal tear. Accumulation of feces at the site of the repair had created a large perirectal cavity. Removal of feces and cleansing of the perirectal cavity were performed daily. Sutures were placed to stabilize, but not reappose, the torn ends of the rectum. The perirectal cavity filled with granulation tissue, and the rectal tear healed.
Bertone AL, Sullins KE, Stashak TS, Norrdin RW.Preformed collagen gel was topically applied to cutaneous wounds of the equine dorsal fetlock (thoracic limb) and metatarsal regions to evaluate the effect on exuberant granulation tissue production and wound healing. In 6 horses and 3 ponies (less than 140 cm high at the withers and less than 365 kg), 36 standardized cutaneous limb wounds were surgically induced (4 wounds/animal); 18 wounds were treated topically with collagen gel, and 18 wounds were not treated (controls). Collagen gel was initially applied to the wound at 0, 2, or 7 days after wound formation (groups 1, 2, and 3, respective...
Acland HM, Gunson DE, Gillette DM.Seven foals aged 18 days to 3 1/2 months had either single or multiple full-circumference segments or long antimesenteric bands of necrotizing duodenitis, sharply delineated from adjacent viable duodenum. Perforation of the necrotic wall had occurred in all foals, leading to acute fibrinous peritonitis. On the mucosal surface severe diffuse, acute inflammation and ulceration involved the anterior half of the duodenum. Two further foals, aged 28 and 30 days, had lesions that are believed to be a chronic form of this disease. Both foals had a thickened duodenal wall, with large areas of mucosa r...
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...
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...
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...
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...
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.
Mackay RJ, Iverson WO, Merritt AM.A 4-year-old stallion was examined because of a 2-month history of inappetance and weight loss. Diarrhoea had also developed a month before presentation. Abnormal clinical findings were emaciation, diarrhoea, ventral oedema, palpable mesenteric lymph node enlargement and a large mass in the left cranial portion of the abdomen. Significant laboratory findings were anaemia (packed cell volume 0.21 litres/litre), hypoalbuminaemia (16 g/litre) and xylose malabsorption. The horse was euthanased and at necropsy a 10.5 kg pendunculated mass composed of granulation tissue was found within and attached...
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...
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.
Tate LP, Sweeney CL, Cullen JM, Corbett WT, Newman HC, Brown TC, Ketner MT.A neodymium:yttrium aluminum garnet (Nd:YAG) laser was used to study effects of applying laser irradiation transendoscopically to the corniculate process of the arytenoid cartilage in horses. Dosimetry was established initially in vitro in 10 corniculate cartilages that were irradiated and examined histologically to determine penetration depths at selected power settings. Eleven horses were given xylazine IV and butorphoral tartrate IV, and their left ventricle and corniculate process were irradiated. Six horses had left laryngeal hemiplegia and were euthanatized and necropsied 14 weeks after ...
Vickers KL, Ross MW.A 4-year-old sexually intact male Standardbred trotter was evaluated for left forelimb lameness. A presumptive diagnosis of severe cartilage damage was made because the horse had a history of infectious arthritis involving the left metacarpophalangeal joint. Arthroscopic evaluation revealed what was presumed to be a large villonodular lesion. The mass was surgically removed, and the horse was treated with procaine penicillin G, trimethoprim-sulfamethoxazole, phenylbutazone, and polysulfated glycosaminoglycans and eventually returned to racing. Histologic examination of the mass revealed a bed ...
Morris DD, Bruce J, Gaulin G, Whitlock RH.Granulocyte transfusions (GT), 0.98 X 10(9) neutrophils/kg of body weight, were performed on 7 healthy pony foals between 2 and 7 days old. The mean neutrophil count of the foals was significantly (P less than 0.05) greater than base line (4,830 +/- 1,260/microliter) 1 hour after GT (8,870 +/- 3,350/microliter) and was similar to base line by 15 to 18 hours after GT (6,550 +/- 2,310/microliter). Leukocyte concentrates (LC) used for GT were harvested from clinically normal adult horses by continuous-flow centrifugation leukapheresis (CL), 3 to 6 hours after hydrocortisone sodium succinate was a...
Sullivan KE, Snyder JR, Madigan JE, Pascoe JR, Farver TB, Thurmond MC, Andresen JW.Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein that regulates the proliferation and maturation of hematopoietic progenitor cells and modulates the function of mature neutrophils. The responses to administration of G-CSF alone, and in combination with antimicrobials, were studied in an equine model of ascending colon ischemia. Complete segmental colonic ischemia (3.75 hours) with pelvic flexure enterotomy was created in four treatment groups. Group 1 horses received recombinant canine G-CSF (10 micrograms/kg, every 24 hours, intramuscularly), gentamicin sulfate (2.2 mg/kg, ever...
Regnier A, Landrevie C, Robin MC, Einsweiler D, Douet JY, Raymond-Letron I.A 6-year-old miniature Shetland pony mare was referred for evaluation of a left corneal mass, which developed from the healing tissue of a corneal traumatic ulceration that had occurred 4 weeks previously. On gross examination, a spherical, smooth-surfaced, and pink-colored lesion of about 1 cm in diameter was protruding from the left palpebral fissure. Ophthalmic examination revealed that it was attached to the scar tissue of the cornea, and that one corpora nigra was adherent to the posterior face of corneal wounded area, without sign of uveitis. The remainder of the ophthalmic examinatio...
Nottrott K, Guio C, Schramme M.We report an unusual case of a young Quarter Horse with a large dental fracture fragment displaced into the maxillary sinus, leaving an oroantral communication that caused food impaction and metaplastic calcification in the sinus and facial deformation with cutaneous fistulation. Oral extraction of a remaining tooth fragment from its alveolus was succeeded by a maxillary sinusotomy for removal of the abnormal sinus contents. Since the oroantral fistula did not heal spontaneously following the placement of a silicone dental prosthesis, minimally invasive transbuccal and transnasal endoscopic ap...
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,...
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...
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...
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...
Mackay RJ, Iverson WO, Merritt AM.A 4-year-old stallion was examined because of a 2-month history of inappetance and weight loss. Diarrhoea had also developed a month before presentation. Abnormal clinical findings were emaciation, diarrhoea, ventral oedema, palpable mesenteric lymph node enlargement and a large mass in the left cranial portion of the abdomen. Significant laboratory findings were anaemia (packed cell volume 0.21 litres/litre), hypoalbuminaemia (16 g/litre) and xylose malabsorption. The horse was euthanased and at necropsy a 10.5 kg pendunculated mass composed of granulation tissue was found within and attached...
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...
Tulleners EP, Harrison IW, Mann P, Raker CW.Left-sided partial arytenoidectomy was performed in eight horses to evaluate healing. Four horses underwent conventional partial arytenoidectomy with suture apposition of the mucosa. In four horses, most of the arytenoid cartilage, including overlying mucosa, vocal fold, and laryngeal saccule, were excised en bloc without mucosal closure. The horses were monitored clinically by endoscopic examination. One horse from each group was euthanatized at weeks 2, 4, 8, and 16. Complete necropsies with gross and histologic examination of the arytenoidectomy sites were performed. Postoperative complicat...
Charlotte C P, Benoit B, Olivier M L.To evaluate secondary intention wound healing in the horse's limbs when treated with the synthetic epidermis spray (Novacika®, Cohesive S.A.S, France) or with a standard bandaging technique. Methods: Six Standardbred mares were included in the study. Four 2.5 x 2.5 cm full-thickness skin wounds were created on each thoracic limb. Two wounds were located on the dorsoproximal aspect of the cannon bone and the other two at the dorsoproximal aspect of the fetlock. Six hours after creation, wounds were randomly treated with synthetic epidermis spray or standard bandaging. The wounds were assessed ...
Pressanto MC, Bombonato C, Foote AK, Coomer RPC.To describe dermoid cyst formation as an uncommon complication of the pinch grafting technique in horses. Methods: Case report. Methods: A 8 year old Arabian gelding. Methods: Clinical presentation, imaging, treatment, and histopathology records were reviewed. The horse originally presented due to delayed healing of a laceration to the distal aspect of the metatarsus. The wound was treated initially with debridement and it was allowed to fill with healthy granulation tissue prior to pinch grafting. Two months after grafting, the horse started to show self-mutilation behavior targeting the woun...
Holz N, Suárez J, Hetzel U, Rampazzo A, Stoppini R.A 15-year-old Swiss Warmblood gelding was presented to the ophthalmology service of Zurich University due to severe visual impairment. Ophthalmic and neurologic examinations were performed, raising suspicion of post-retinal blindness. Standing contrast computed tomography (CT) of the head revealed a partially calcified, soft tissue attenuating mass in the sphenopalatine sinus with concurrent compression of the optic nerves and chiasm. Differential diagnosis included neoplasia and granulomatous disease. The horse was euthanized, and the head was subsequently examined by magnetic resonance imagi...
Kamm JL, Odegaard J, Gaida J, King N.This tutorial aims to illustrate and instruct on the technique of punch skin grafting in the horse. Unassigned: A 10-year-old paint gelding with a 9 X 6-cm chronic granulating wound to the left forelimb was utilized for this tutorial. Unassigned: The chronic wound was debrided with sharp dissection, and the limb was pressure bandaged overnight. Twenty-four hours later, the horse was sedated for punch skin grafting. The ventral pectoral region was aseptically prepared for skin harvest and locally anesthetized. An 8-mm biopsy punch was used to harvest the grafts. The subcutaneous tissue was then...
Dos Santos TS, Dillmann JB, Giovelli M, Elias GO, Lima RK, Cescon S, Stainki DR, Dos Santos RC, Corrêa C, Monteiro SG.This study reports the successful use of maggot therapy in four horses with traumatic wounds caused by wire fences, treated in veterinary clinics and under field conditions in southern Brazil. All lesions showed tissue necrosis, purulent discharge, and foul odor, indicating infection and delayed healing. Sterile Lucilia cuprina larvae (L1 stage) were applied directly to the wounds for 48 hours. Rapid improvement was observed, with marked reduction of necrotic tissue, exudate, and odor, and stimulation of granulation tissue in three cases. Complete wound closure occurred between 10 and 60 days ...
Loyd A, Neto R, Caldwell F, Boone L, White A.This study aimed to determine the safety and macroscopic/microscopic effects of fluorescence biomodulation (FBM) on experimentally induced, full-thickness, distal limb wounds in horses.This was an experimental study ( = 6 horses). Two full-thickness wounds were created on both dorsal metacarpi of six adult horses. Each forelimb was randomly allocated to either control (no FBM) or treatment (FBM) and randomly allocated to visual or histological assessment of healing. Wounds were treated within each experimental group every 7 days for four treatments. Fluorescence biomodulation wounds were ...
Partusch L, Rutland CS, Martens A, Du Cheyne C, De Spiegelaere W, Michler JK.Exuberant granulation tissue (EGT) is a second intention wound healing disorder. It commonly occurs in the distal limb of horses. EGT causes significant increase in the duration and cost of treatment, potentially leading to the decision not to pursue treatment and euthanize the patient. The underlying pathomechanisms of this fibroproliferative disorder remain unclear, particularly in terms of collagen composition and the association between myofibroblasts and blood vessels. This study investigated the collagen composition in naturally occurring EGT following trimming in 19 horses (EGT group). ...
DiBello D, Cassel N, Granacka V, Beard L, Rosado SC, Hill-Thimmesch K, Avellar H.Equine sarcoidosis is an uncommon disease characterized by granulomatous inflammation presenting in a spectrum of body system involvement and severity. Musculoskeletal manifestations are sporadically reported but without correlation between imaging and pathologic findings. In a mature Quarter Horse mare eventually diagnosed with a progressive form of sarcoidosis, phalangeal osteolysis discovered on radiography prompted further evaluation, revealing diffuse, discrete osteolysis throughout the axial skeleton. Due to disease progression, humane euthanasia was elected, and computed tomography and ...
Accorroni L, Dini F, Pilati N, Marchegiani A, Bazzano M, Spaterna A, Laus F.Wound management is a fundamental skill for veterinarians, requiring a systematic approach to wound care and a deep understanding of the biological principles underlying healing. Sucralfate, widely known as a mucoprotective agent for gastroduodenal ulcers, has recently shown promising topical effects in human skin lesions by binding and protecting growth factors from proteolytic degradation, thereby enhancing their local availability. This action promotes angiogenesis, chemotaxis and cell proliferation, while reducing oxidative stress and exerting bacteriostatic and bactericidal effects agains...
