Topic:Thrombosis
Thrombosis in horses refers to the formation of blood clots within blood vessels, which can impede normal blood flow and lead to various health issues. This condition can occur in both veins and arteries, affecting different parts of the equine circulatory system. Thrombosis can result from a variety of factors, including endothelial damage, changes in blood flow, and alterations in blood composition. In horses, common sites for thrombosis include the jugular vein and digital veins. Clinical signs may vary depending on the location and severity of the clot. This page compiles peer-reviewed research studies and scholarly articles that explore the pathophysiology, diagnosis, and management of thrombosis in horses, providing insights into its impact on equine health and potential treatment strategies.
Reconstruction of the jugular vein in horses with post thrombophlebitis stenosis using saphenous vein graft. A surgical technique is described in which a saphenous vein graft is used to reconstruct the jugular vein in horses with facial oedema due to post thrombophlebitic stenosis of the jugular vein. The saphenous vein was harvested from the contralateral limb and implanted in the occluded vein by 2 side-to-end anastomoses. Intra- and post operatively anticoagulative medication was administered. In 2 out of 3 patients the reconstruction resulted in a permanent patent graft and resolution of the facial oedema. In one patient the graft thrombosed.
Aorto-iliac thrombosis in a foal. A six-day-old Missouri foxtrotter colt was examined because it had had diarrhoea since it was 24 hours old. A diagnosis of colitis, septicaemia, and disruption of the arterial blood flow to the pelvic limbs was made on the basis of clinical and laboratory findings. Despite intensive medical therapy, the foal died 13 hours after being examined. Postmortem examination revealed diffuse fibrinous enteritis with lymphoid necrosis, multifocal fibrinonecrotic typhlocolitis, disseminated intravascular coagulation, and a large occluding thrombus at the aortic termination. The results of bacteriological...
Ultrasonography of the femoral artery in six normal horses and three horses with thrombosis. Ultrasonography of the femoral artery in the horse, including color, power and spectral Doppler, provides morphologic and dynamic information. This paper describes the use of the techniques in six clinically normal horses and three with femoral artery thrombosis. Useful landmarks for orientation are the saphenous artery and the medial saphenous vein. The lateral circumflex femoral artery can not be visualized. Recognition of the genus descendens artery is complicated due to the presence of multiple distal caudal femoral arteries. The femoral artery feeds a high resistance bed. In normal horses...
[Surgical treatment of an obliterating thrombosis of the jugular vein in a horse. Use of synthetic vessel prosthesis]. A 6-year-old trotter gelding presented with exercise intolerance and swelling of the left side of the head during exercise and grazing. The complaints were caused by a complete thrombosis of the left jugular vein. In this case report a surgical approach is described in which a bypass was created with a synthetic vascular graft. After treatment the horse was capable of racing at his former level. The patency of the synthetic graft was 11 months.
Hemostatic and fibrinolytic indices in neonatal foals with presumed septicemia. Thirteen coagulation tests evaluating hemostatic and fibrinolytic indices and serum cytokine and plasma endotoxin concentrations were obtained in 34 foals with a positive sepsis score (septic group) and 46 age-matched healthy foals. Compared to healthy foals, the prothrombin, activated partial thromboplastin, and whole blood recalcification times were significantly longer in septic foals. The fibrinogen and fibrin degradation products concentrations, percent plasminogen, alpha-2 antiplasmin, and plasminogen activator inhibitor activities, and tumor necrosis factor and interleukin-6 activities ...
Thrombosis resulting in rectal perforation in a horse. A 12-year-old Quarter Horse gelding was admitted to the veterinary medical teaching hospital with a 2-day history of signs of abdominal pain. Initial findings on physical examination included signs of lethargy, dehydration, diarrhea, and gastric reflux. Results of laboratory testing indicated that the horse had panleukopenia with neutrophilic toxic changes, was dehydrated, and was hypocalcemic. During the first 48 hours of hospitalization, 1 abdominal palpation per rectum and 3 analyses of peritoneal fluid were performed; abnormalities were not detected. A preliminary diagnosis of enterocoliti...
Thrombosis of the aorta and the caudal arteries in the horse; additional diagnostics and a new surgical treatment. The prognosis of aortic-iliac thrombosis (TAI) is usually considered to be poor, although affected horses are reported to have recovered following treatment with sodium gluconate. This paper presents some diagnostic techniques to monitor the development of hypoxemia in the diseased limb and to visualise the extension of the thrombosis into the femoral artery. Also, a surgical technique using a Fogarty thrombectomy catheter for partial or total removal of thrombi to restore blood flow, is described. One horse recovered completely, allowing it to resume its former career, the other horse improve...
Microvascular thrombosis associated with onset of acute laminitis in ponies. The hypothesis that equine laminitis is caused by thrombosis of vessels in the laminar corium (dermis) was investigated. Hemostatic alterations were evaluated by determining platelet count, platelet survival, platelet adhesiveness to vascular subendothelium, activated clotting time, and whole blood recalcification time. Thrombosis of vessels in the hoof wall was evaluated by scintigraphic studies of the hoof wall after administration of indium-111 (111In)-labeled platelets, contrast arteriography, and histologic examination. Platelet count remained constant before and at the onset of lameness;...
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...
Effects of 5% and 10% guaifenesin infusion on equine vascular endothelium. Twelve horses of various breeds and either sex were anesthetized with xylazine and ketamine injected into a median or lateral thoracic vein. During anesthesia, with the horse in sternal recumbency, a 14-gauge, 8.9 cm catheter was inserted into each jugular vein by using aseptic technique. Guaifenesin in water (100 mg/kg or a maximum dose of 50 grams) was infused into one jugular vein and an equal volume of 0.9% saline solution was infused into the other jugular vein. Seven horses received 10% guaifenesin, and five horses received 5% guaifenesin. The catheters were removed before the horses rec...
Ejaculatory failure associated with aortic-iliac thrombosis in two stallions. Two mature breeding stallions were evaluated because of specific ejaculatory dysfunction, and each was found to have aortic-iliac thrombosis occluding 60 to 70% of the aortic lumen. In each case, the stallion had strong libido, normal mounting, and vigorous initial thrusting. With continued exertion, thrusting became weak and dismount was awkward. Treatment aimed at maximizing sexual arousal before mounting and reducing hind limb pain and exertion during breeding allowed these stallions to continue breeding. A program of gradually increasing daily exercise also was associated with improved bre...
Priapism in a stallion with generalized malignant melanoma. A Thoroughbred stallion developed priapism that was unresponsive to medical treatment and lavage of the corpus cavernosum penis with heparinized 0.9% NaCl solution. Three weeks after onset of priapism, the penis was firm and noncompliant, and penile pain sensation and ability to retract the penis were lost. Ultrasonography confirmed thrombosis of the corpus cavernosum penis. The stallion was euthanatized because of poor prognosis for return to breeding soundness. Necropsy revealed enlargement of numerous lymph nodes. The dorsal penile nerves were demyelinated distal to the crura of the penis. ...
Histology and morphometry of Strongylus vulgaris-mediated equine mesenteric arteritis. Histological and morphometric evaluation of equine cranial mesenteric arteries was performed on 239 and 89 arteries, respectively. Histological examination revealed that thrombosis and the severity of inflammation varied on a seasonal basis and were directly associated with larval presence. Intimal and adventitial fibrosis were generally of greater severity than medial fibrosis. Fibrosis of the vasa vasorum was less frequent than fibrosis of the artery itself. Morphometry revealed a significant increase in intimal, adventitial and, to a lesser extent, medial area in affected as compared with n...
Vascular injury associated with naturally occurring strangulating obstructions of the equine large colon. Ten horses were euthanatized before, during, or after surgery to correct severe volvulus of the large colon. At surgery, the colonic serosa changed from blue-gray, blue or purple toward a more normal pink in seven horses after the volvulus was corrected. The mucosa consistently remained black or dark red. Results of postmortem colonic microangiography revealed perfusion of the serosa and the circular and longitudinal muscle layers, but mucosal perfusion was limited by thrombosis in the muscularis mucosae and submucosa. There was evidence of thrombosis of the mesenteric colic vessels in six hor...
Infarction of the pons and medulla oblongata caused by arteriolar thrombosis in a horse. Infarction of the pons and rostral medulla secondary to arteriolar thrombosis was documented histologically in a 17-year-old mixed-Arabian female horse. Clinically, the animal experienced a sudden onset of a head tilt and subsequent non-controllable seizures. There was no historical, clinical or histological evidence to suggest the presence of infection of Equine Herpesvirus-1 or the feeding of corn contaminated by Fusarium moniliforme.
Endometrial adenocarcinoma in a mare. An endometrial adenocarcinoma with metastases to the lung, liver, spleen, mesentery and serosal peritoneal surfaces was found in an 11-year-old Arabian mare. Clinical signs included generalized weight loss, depression, anorexia, ventral edema and abdominal distension. Ascites was due to thrombosis of the caudal vena cava. The diagnosis of endometrial adenocarcinoma was based on the histological appearance of uterine glandular epithelium and the presence of similar tissue in the metastatic tumors.
Invasive pulmonary aspergillosis of horses: an association with acute enteritis. Invasive pulmonary aspergillosis was identified in 19 horses. In 16 cases mycotic lesions were associated with enterocolitis; 14 cases appeared to result from Salmonella infection. Pulmonary lesions included multifocal areas of acute necrosis, leukocytoclastic vasculitis, and thrombosis with fibrinosuppurative inflammation surrounding mycelial masses. Thromboemboli with fungi were in the brain and kidneys of three cases. Factors which appeared to predispose to pulmonary aspergillosis included corticosteroid therapy, disseminated neoplasms, hepatitis, pleuritis, and peritonitis. This study sugg...
Use of ultrasonography for the detection of aortic-iliac thrombosis in horses. Two dimensional ultrasonographic evaluation of the iliac arteries and terminal portion of the aorta was utilized in 18 horses with histories of exercise intolerance or hindlimb lameness. A plaque or thrombus was imaged in one or more of these vessels in 5 horses. In 2 horses, the initial rectal examination findings were normal and the thrombus may have been missed without the use of diagnostic ultrasonography.
Endothelial cell infection and thrombosis in paralysis caused by equid herpesvirus-1: equine stroke. Eight mares were infected with equid herpesvirus-1 subtype 1 isolated from a case of equine paresis. In two mares killed at 4 d.p.i. immunofluorescence showed endothelial cell infection together with thrombosis in the rete arteriosus of the nasal mucosa and also in the spinal cord of one of these mares. Circulating platelet counts in the other six mares fell as early as 2 d.p.i. and remained depressed for seven days. Circulating immune complexes started to appear at 2 d.p.i., reached maximum levels at 10 d.p.i., but were undetectable at 28 d.p.i. Three of the six remaining mares developed vary...
Ultrasonographic diagnosis of aorto-iliac thrombosis. A linear array 5 mHz ultrasonic scanner was used to diagnose aorto-iliac thrombosis in a 3 year old Standardbred gelding. There are no reports in the literature of utilization of ultrasonography for visualization of an aortic thrombus. The technique is fairly non-invasive, requiring only a rectal examination with a linear array probe. Arteriography is the only other method described for actual visualization of a thrombus. This procedure is technically difficult and highly invasive.
Arterial thrombosis as the cause of lameness in a foal. A 3-day-old foal was examined because of forelimb lameness. Brachial artery occlusion was diagnosed. The foal was euthanatized. Necropsy revealed brachial artery thrombosis and an atrial septal defect.
Occlusion of internal carotid artery in the horse by means of a balloon-tipped catheter: evaluation of a method designed to prevent epistaxis caused by guttural pouch mycosis. A procedure developed to occlude the internal carotid artery of horses with guttural pouch mycosis was modified was modified and evaluated in nine clinically normal horses. The left internal carotid artery was ligated at its origin and occluded distally with an intraluminal balloon catheter. In four horses, the balloon-tipped catheters were left in place until these horses were euthanatized at 4 to 244 days after surgery. In the remaining horses, the catheters were removed after 10 to 14 days by a cutdown procedure, and these horses were euthanatized 1 to 60 days after catheter removal. In bot...
Ischaemic necrosis of the navicular bone and its treatment. In a survey of 95 control horses and 16 horses with navicular disease, the incidence of erosions and discoloration of the flexor cartilage of the navicular bone was no different between the control horses and those with navicular disease. All cases of navicular disease showed thrombosis of the distal navicular nutrient arteries and this could be related to a change to a rounded or flask shape of the distal nutrient foramen of the navicular bone. Erosions and discoloration of the navicular bone are therefore of no significance in navicular disease. Previously described lines of treatment are of...
Traumatic duodenitis with subsequent thrombosis of the posterior vena cava in a horse. The possible sequelae of traumatic perforation
of the reticulum of cattle are described by Blood
and Henderson (1963). Traumatic splenitis and
hepatitis following perforation of the reticulum
have also been described in detail (Blood and
Hutchins 1955).
Frank (1959) described and illustrated both
thrombus formation and stricture of the posterior
vena cava following traumatic reticulitis with subsequent abscess formation. The proximity of the
abscess to the posterior vena cava apparently
caused erosion of the vessel wall, and the inflammatory reaction initiated the formation of a
thr...