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Topic:Necrosis
Necrosis in horses refers to the localized death of cells or tissues within the body, often resulting from factors such as injury, infection, or compromised blood supply. This pathological process can affect various tissues, including skin, muscle, and internal organs. Necrosis may manifest as visible lesions, swelling, or tissue discoloration, and can lead to further complications if not addressed. Understanding the underlying causes and mechanisms of necrosis is important for effective management and treatment in equine veterinary practice. This page compiles peer-reviewed research studies and scholarly articles that explore the causes, mechanisms, and implications of necrosis in horses, providing insights into diagnostic and therapeutic approaches.
Ischemia/reperfusion injury of the ascending colon in ponies: a correlative study utilizing microvascular histopathology and corrosion casting. Volvulus of the ascending colon (ACV) in the horse results in microvascular injury and necrosis of the intestinal mucosa. This study investigated the site and type of microvascular injury which occurs within the mucosa and submucosa following ACV. Histopathology of volvulus treated ponies demonstrated mucosal necrosis with microvascular hemorrhage and thrombosis. Thrombi occurred within the subepithelial capillaries and edema and hemorrhage developed throughout the mucosa and submucosa. Vascular casts allowed 3-D viewing of samples obtained from the entire pelvic flexure and demonstrated two d...
Myocarditis following envenoming with Vipera palaestinae in two horses. Cardiac disease developed several days to weeks after resolution of local inflammation caused by envenoming by Vipera palaestinae in two horses. In one horse (case A), referred to the hospital for recurrent abdominal pain 8 days after envenoming, a tachyarrhythmia was detected; ventricular premature depolarizations were diagnosed by ECG. A second horse (case B) was found dead without premonitory signs 60 days after envenoming. In both horses, there was extensive necrosis of cardiac ventricular tissues.
Hepatic lobe torsion as a cause of colic in a horse. A 14-year-old Arabian gelding was examined for colic. An exploratory celiotomy was subsequently performed and the left lobe of the liver was found to be twisted. The lobe was resected using a TA-90 surgical stapling instrument. Histologic examination of the resected liver indicated portal vein and sinusoid dilation and congestion with blood. There were focal areas of necrosis and bacterial cocci and rods throughout the section. The histologic findings were consistent with hepatic lobe torsion. After surgery, the horse was treated with broad spectrum antibiotics, anti-inflammatory drugs, hepari...
A prospective study of septicaemia in colostrum-deprived foals. Fourteen mares and their foals were attended at parturition. After mare-foal bonding, 8 colostrum-deprived (CD) foals were removed from their dams, deprived of colostrum, and provided with an alternative milk source for the first 24 h of life. The mares were milked out every 2-4 h during this period to remove colostrum, after which the CD foals were returned to their mares and allowed to nurse. Six colostrum-fed (CF) foals were allowed to suck colostrum in the normal manner. Foal serum IgG concentration was determined by single radial immunodiffusion (means, CD = 0 mg/dl; CF = 1,508 mg/dl). Ac...
Cutaneous pythiosis in horses from Brazil. Equine pythiosis was studied in five animals from two farms located in a swampy region of southern Brazil (Rio Grande do Sul State). Granulomatous lesions exuding necrotic material and containing a central yellow and firm tissue core, the 'kunker', were observed on the top of the nose of one horse, on the abdomen of two horses and on the hind limbs of two other animals. Direct microscopic preparations, histopathological examination of lesion material, and macroscopic and microscopic characteristics of the isolates confirmed the diagnosis of pythiosis. Surgical intervention of the inflammatory ...
Generalized medullary infarction of the long bones in a horse. Generalized medullary infarction of the long bones was diagnosed in a 12-year-old Tennessee Walking Horse mare. The mare was referred after a 6-week course of shifting weight on her hind limbs, and kicking. Physical examination revealed mild stifle joint distention and withdrawal reactions to digital pressure over the long bones. Radiography revealed patchy areas of medullary sclerosis in the distal portion of each femur and proximal portion of each tibia. A full-thickness cortical and cancellous tibial biopsy revealed infarcted bone marrow, with cortical and periosteal osteonecrosis. The caus...
Segmental ischemic necrosis of the small intestine in two postparturient mares. Two mares developed segmental ischemic necrosis of the small intestine after parturition. In one mare, the mesentery of the small intestine apparently tore during parturition, after which necrosis developed in a 52-cm segment of the distal portion of jejunum. In the other mare, a 52-cm segment of the proximal portion of ileum tore during parturition. Three weeks later, a 40-cm segment of the distal portion of jejunum became incarcerated in the mesenteric rent and twisted 360 degrees on its mesentery. Both mares recovered after resection of affected intestine and are functioning as broodmares.
Etiology and pathology of equine placentitis. Placentas from aborted, stillborn, and premature foals were examined during the 1988 and 1989 foaling seasons, and 236 of 954 (24.7%) had placentitis. Microorganisms associated with placentitis were isolated or demonstrated from 162 of 236 (68.6%) placentitis cases. Leptospira spp. and a nocardioform actinomycete were 2 important, newly emerging bacteria associated with equine placentitis. Major pathogens identified in decreasing order were Streptococcus zooepidemicus, Leptospira spp., Escherichia coli, a nocardioform actinomycete, fungi, Pseudomonas aeruginosa, Streptococcus equisimilis, Ente...
Muscle histopathology and plasma aspartate aminotransferase, creatine kinase and myoglobin changes with exercise in horses with recurrent exertional rhabdomyolysis. Six horses with a history of recurrent exertional rhabdomyolysis (RER) (Horses A-F) and 7 control horses performed a submaximal and later a near-maximal treadmill exercise test. Blood samples were obtained before, during and after exercise and muscle biopsies were taken before and after exercise. At rest, plasma aspartate aminotransferase (AST) activities in horses with RER were above 95% confidence intervals for control horses. During submaximal exercise, 3 horses with RER (A, B and C) had much greater increases in plasma AST, creatine kinase (CK) and myoglobin concentrations than did Horses ...
Experimental equine leukoencephalomalacia, toxic hepatosis, and encephalopathy caused by corn naturally contaminated with fumonisins. A study to evaluate the effects of dietary fumonisin B1 was conducted using 6 ponies (4 test and 2 control). A ration naturally contaminated with fumonisin B1 was fed in 3 phases: 1) 44 ppm fumonisin B1, 2) less than 1 ppm fumonisin B1, and 3) 88 ppm fumonisin B1. All ponies were monitored daily, weighed weekly, and limit fed at a rate of 0.8% body weight plus hay. Feed intake was measured daily, and a serum chemistry panel was completed once or twice weekly. Four to 7 days after initiation of the trial (Phase 1), all 4 test ponies had decreased feed consumption, and selected serum chemistry p...
Effects of holmium:YAG laser on equine articular cartilage and subchondral bone adjacent to traumatic lesions: a histopathological assessment. This study was performed to investigate the effects of holmium:yttrium-aluminum-garnet (Ho:YAG) laser energy on articular cartilage and subchondral bone adjacent to traumatically created cartilage lesions in a continuous weight-bearing model. The 2.1-microns wavelength was delivered efficiently and precisely in hand-controlled contact and near-contact hard tissue arthroscopic surgery in a saline medium. Bilateral arthroscopy was performed on normal antebrachiocarpal and intercarpal joints of four adult horses. One hundred twenty traumatic lesions were created on three weight-bearing articular ...
Fate and effect of autogenous osteochondral fragments implanted in the middle carpal joint of horses. Four autogenous osteochondral fragments removed from the lateral trochlear ridge of the talus were arthroscopically placed as loose bodies in a randomly selected middle carpal joint in each of 10 horses. The contralateral middle carpal joint, subjected to a sham procedure, served as control. Postoperative treatment was consistent with that for clinical arthroscopic patients. Lameness evaluation, radiographic examination, carpal circumference measurement, and synovial fluid analysis were performed before and at scheduled intervals after surgery. After a 2-month confinement, horses were subjecte...
Effects of intra-articular administration of methylprednisolone acetate on normal articular cartilage and on healing of experimentally induced osteochondral defects in horses. The effects of intra-articular administration of methylprednisolone acetate (MPA) on the healing of full-thickness osteochondral defects and on normal cartilage were evaluated in 8 horses. In group-1 horses (n = 4), a 1-cm-diameter, full-thickness defect was created bilaterally in the articular cartilage on the dorsal distal surface of the radial carpal bone. Cartilage defects were not created in group-2 horses (n = 4). One middle carpal joint was randomly selected in each horse (groups 1 and 2), and treated with an intra-articular injection of 100 mg of MPA, once a week for 4 treatments. Inje...
Conservative management of uroperitoneum in a gelding. Uroperitoneum as a sequela to urethral calculus in an adult gelding was successfully managed by use of subischial urethrotomy and abdominal drainage. Necrosis of bladder mucosa was seen endoscopically, but a tear or rupture was never identified. Peritonitis developed but was controlled with antibacterial treatment. Although uroperitoneum is usually a sequela to bladder rupture and the ideal treatment is surgical repair, conservative management may be warranted in selected cases.
Measurement of serum myoglobin concentrations in horses by immunodiffusion. Quantitative immunodiffusion in one dimension was performed in 6-mm Duran tubes containing a 1% Nobel agar solution and various dilutions of antisera. A series of dilutions of pure myoglobin in equine sera as well as plasma from horses with rhabdomyolysis were tested. Standard curves were prepared of the migration distance of the formed precipitate from the meniscus of the gel after 3, 6, 12, and 24 hours. The clearest line of precipitate was formed with a 1:20 dilution of antisera in agar. Standard curves were nonlinear and plasma myoglobin could be detected at 2 micrograms of myoglobin/ml or...
Septic metritis secondary to torsion of a pedunculated uterine fibroleiomyoma in a filly. A 2-year-old Arabian filly was referred for evaluation of a serosanguineous vaginal discharge. Palpation per rectum revealed a large, fluid-filled uterus and a uterine mass. The filly developed septic metritis and secondary laminitis as a result of torsion and necrosis of a pedunculated uterine mass. Ovariohysterectomy was performed. The entire cervix was removed with the uterus. Gross examination of the excised uterus revealed 3 intraluminal masses. Histologic evaluation identified the tumors as fibroleiomyoma. The filly recovered completely, and there was no recurrence of the tumor.
[Scanning electron microscopic findings of the navicular bone and deep flexor tendon in podotrochlosis of horses]. In 25 adult horses the podotrochlea of 49 forelimbs was examined by means of light and electron microscopy in order to correlate clinical and morphological findings. According to the clinical diagnosis the animals were divided into three groups: lameness due to syndrome of podotrochlosis (group 1) or due to tendopathy (group 2) and horses without lameness (group 3). The most striking pathological findings of the navicular bone and the opposite surface of the deep flexor tendon were found in horses with podotrochlosis, consisting of loss of cartilage and tendon matrix with denudation of collage...
Postpartum partial cystectomy through the vagina in a mare with everted partially necrotic bladder. The bladder of a 750-kg Clydesdale mare had everted through the urethra into the vagina immediately after parturition. The bladder was reinverted into the peritoneal cavity by an attending veterinarian, but 4 days later, the bladder was everted again in the vagina. The mare was able to void urine through both ureters, which could be seen in the mucosal surface of the bladder. The everted bladder had become edematous and could not be reinverted through the urethra. A considerable portion of the fundus was necrotic. The mare was administered xylazine epidurally to induce perineal analgesia, and ...
Hypoglycemia and hepatic ischemic necrosis after small intestinal incarceration through the epiploic foramen in a horse. A 16-year-old stallion was presented to the Louisiana State University Veterinary Teaching Hospital for evaluation of acute abdominal pain. Physical examination and diagnostic procedures indicated a strangulating obstruction of the small intestine. At exploratory celiotomy, a strangulating incarceration of the jejunum through the epiploic foramen was found. The incarcerated small intestine was reduced, then resection of the nonviable bowel and anastomosis performed. After surgery, the horse exhibited clinical signs and laboratory findings associated with hypoglycemia and died in spite of emerg...
[Teratogenic effect of the Venezuelan equine encephalitis virus: a review of the problem]. Clinical findings on Venezuelan Equine Encephalitis virus infection and the teratogenic effects of several Togaviruses are described. Similarities between the intrauterine alterations induced by Venezuelan Equine Encephalitis virus and rubella virus are pointed out. Findings described by Wenger in 1967 were those of massive cerebral necrosis in fetuses of women presumably suffering of encephalitis and they are commented along with the development of an animal experimental model at the end of 1970-1980. Pathogenesis of the intrauterine infection seemed to be related to changes in the placental ...
Hepatoencephalopathy and hypocalcemia in a miniature horse mare. A pregnant, miniature horse mare had clinical signs of hepatoencephalopathy and concurrent hypocalcemia. The signs included dullness, inappetence, blindness, head pressing, weakness, muscle fasiculations, uveitis, and urinary incontinence. Hepatic dysfunction and hypocalcemia were confirmed by serum biochemical analysis. The mare was treated successfully with a continuous infusion of Ringer solution, calcium gluconate, dextrose, B-complex vitamins, sodium ampicillin, and flunixin meglumine; topical administration of ophthalmic ointments; and decompression of the urinary bladder. Histologic exa...
Mesenteric tears of the descending (small) colon as a postpartum complication in two mares. Segmental ischemic necrosis of the descending colon associated with discrete tears of the mesocolon were diagnosed in 2 mares following foaling. After foaling, both mares had a slow onset of signs of abdominal pain and gradual deterioration of clinical status. Increases in peritoneal fluid total protein concentration and WBC count and a palpable impaction of the descending colon on examination per rectum were useful diagnostic aids. Surgical intervention was successful in one mare, but not in the other.
Trophoblast-uterine interactions during equine chorionic girdle cell maturation, migration, and transformation. The structure of the equine chorionic girdle between days 28 and 42 of gestation was examined. Of particular interest were differentiation of trophoblastic cells within the girdle, adhesion between girdle and endometrium, invasion and displacement of the uterine epithelium, and the nature of the endometrium when girdle cells migrate into it to form endometrial cup cells. The chorionic girdle, identified initially as a band of tall columnar cells, becomes a stratified columnar epithelium indented by clefts and pits. Adhesion to and penetration through the endometrial luminal epithelium are rapi...
Histopathological and ultrastructural changes in simulated large colonic torsion and reperfusion in ponies. This investigation examines the histological and ultrastructural lesions of the colonic mucosa during terminal experimental infarction and subsequent reperfusion. Four ponies were anaesthetised and subjected to surgical torsion of the colon. Biopsies were collected at hourly intervals for 3 h, at which point the torsions were corrected. Circulation was re-established for 2 h and the bowel was re-biopsied at hourly intervals. The ponies were killed while under anaesthesia. During the 3 h experimental infarction, the bowel became macroscopically thickened and dark purple. Histologically, the muc...
The isolated perfused equine skin flap. Preparation and metabolic parameters. A model for the study of equine cutaneous physiology, pharmacology, and toxicology was developed. Four 4 x 12 cm and twenty-one 6 x 12 cm single-pedicle axial pattern skin flaps based on the caudal superficial epigastric artery, and eight 6 x 12 cm flaps based on the saphenous artery and medial saphenous vein, were raised and sutured in a tubed configuration. On day 2, each flap was removed, the artery was cannulated, and the flap was perfused with a modified Krebs-Ringer's albumin-based medium for at least 6 hours. Flap viability was assessed by glucose use, lactate production, and histologic...
Erythema multiforme in two horses. Erythema multiforme is reported for the first time in 2 South African horses. Both horses displayed a sudden, fulminant outbreak of raised, non-alopecic and non-pruritic plaques over the dorsolateral aspects of the neck and trunk. In both cases the distribution of the lesions was bilaterally symmetrical. Histopathological findings included hydropic degeneration of basal epidermal cells, eosinophilic necrosis of individual or groups of keratinocytes, intra-epidermal and sub-epidermal cleft formation and mixed, dermal, perivascular infiltrates. An initiating cause could not be identified in eith...
Fusion of the distal intertarsal and tarsometatarsal joints in the horse using intraarticular sodium monoiodoacetate. Six normal horses received 3 intra-articular injections of sodium monoiodoacetate (MIA) in the distal intertarsal (DIT) and tarsometatarsal (TMT) joints of one hindlimb. Injections were at three week intervals, and post injection pain was controlled with routine administration of phenylbutazone for five days following each injection. All horses underwent a gradually increasing exercise programme consisting of walking and trotting beginning one week after the first injection and continuing for 24 weeks. All treated joints showed increasingly severe radiographic evidence of degenerative joint di...
Pulsed carbon dioxide laser for cartilage vaporization and subchondral bone perforation in horses. Part II: Morphologic and histochemical reactions. A pulsed carbon dioxide laser was used to vaporize articular cartilage in four horses, and perforate the cartilage and subchondral bone in four horses. Both intercarpal joints were examined arthroscopically and either a 1 cm cartilage crater or a series of holes was created in the third carpal bone of one joint. The contralateral carpus served as a control. After euthanasia at week 8, the treated and control joints were examined for gross changes, and samples of cartilage and subchondral bone, synovial membrane, and peripheral lymph nodes were examined histologically. Depletion of cartilage ma...
Spinal cord ischemic necrosis due to fibrocartilaginous embolism in a horse. No abstract available
Black walnut (Juglans nigra) toxicosis: a model for equine laminitis. Twelve light horse geldings developed laminitis within 8 to 12 h of being dosed by nasogastric tube with an aqueous extract of black walnut (Juglans nigra). Four of the 12 horses developed the severe signs of grade 3 laminitis (lame at a walk, refused to lift feet). Laminitis was accompanied by mild depression and limb oedema. There was no evidence of shock or colic. The horses developed neutropenia by 4 h after dosing with the extract, which shifted to a relative neutrophilia by 8 to 12 h. Minimal increases in plasma epinephrine and cortisol concentrations were suggested in severely affected ...
