Venae
The venous system is the complete venous network returning deoxygenated blood to the heart. The jugular veins are the most accessible for venipuncture and catheterization. The hepatic portal system carries nutrient-rich blood from the gastrointestinal tract to the liver. Venous return from the hoof relies partly on the frog mechanism: weight-bearing compresses digital veins to pump blood upward. The venous system also includes the cranial and caudal vena cava and their tributaries.
Jugular thrombophlebitis is a common complication of prolonged catheterization. Digital venous congestion can contribute to hoof problems. Relevant in evaluations of circulatory function and after trauma.
## Overview Jugular thrombophlebitis is inflammation and clotting of the jugular vein, most often from intravenous catheterization. The vein becomes hard, swollen, and painful. Bilateral involvement
## Overview Purpura hemorrhagica is an immune-mediated vasculitis that usually follows strangles or influenza. Antigen-antibody complexes damage blood-vessel walls, causing leakage. Signs appear 2 to
## Overview Disseminated intravascular coagulation (DIC) is a serious disorder of clotting in which widespread activation of coagulation consumes platelets and clotting factors, leading to both throm
Prolonged jugular catheters increase the risk of thrombosis. Monitor catheter sites for swelling or heat. The frog mechanism is important for normal venous return from the foot.
## Overview Jugular thrombophlebitis is inflammation and clotting of the jugular vein, most often from intravenous catheterization. The vein becomes hard, swollen, and painful. Bilateral involvement can cause marked facial edema. Septic thrombi may abscess. ## Causes Catheter-related trauma or infection, or perivascular injection of irritating drugs. ## Diagnosis Palpation of a cord-like vein and ultrasound showing thrombus. Culture if infection is suspected. ## Treatment Remove the catheter, anti-inflammatories, hot packing, and antibiotics if septic. Anticoagulants are sometimes used. Most cases resolve over weeks, though the vein may remain partially occluded. ## Recovery and Prognosis Good for unilateral cases. Bilateral thrombosis causes more significant swelling but usually improves. ## Prevention Aseptic catheter placement, proper securement, and prompt removal when no longer needed. Signs include: hard swollen painful jugular vein; facial edema if bilateral; heat and pain on palpation
## Overview Purpura hemorrhagica is an immune-mediated vasculitis that usually follows strangles or influenza. Antigen-antibody complexes damage blood-vessel walls, causing leakage. Signs appear 2 to 4 weeks after infection and include severe edema of the limbs, head, and ventral abdomen, petechial hemorrhages on mucous membranes, fever, and depression. It is not contagious. ## Causes Type III hypersensitivity, most often after Streptococcus equi infection. ## Diagnosis History and clinical signs. Skin biopsy or bloodwork supports the diagnosis. ## Treatment Corticosteroids to suppress the immune reaction, plus antibiotics if active infection is present. Supportive care for edema. Most mild to moderate cases recover. ## Recovery and Prognosis Good for most cases with prompt treatment. Severe vasculitis can cause skin sloughing or organ damage. ## Prevention Appropriate strangles management. Avoid vaccination of horses with very high strangles titers in some protocols. Signs include: severe limb and ventral edema; petechial hemorrhages; fever; depression; often 2 to 4 weeks after strangles
## Overview Disseminated intravascular coagulation (DIC) is a serious disorder of clotting in which widespread activation of coagulation consumes platelets and clotting factors, leading to both thrombosis and bleeding. It is almost always secondary to another critical illness, most often sepsis, endotoxemia, or severe gastrointestinal disease. ## Causes Sepsis, endotoxemia, neoplasia, or severe systemic inflammation triggering uncontrolled coagulation. ## Diagnosis Clinical signs of bleeding (petechiae, prolonged bleeding from venipuncture sites) plus laboratory evidence of thrombocytopenia, prolonged clotting times, and elevated fibrin degradation products. ## Treatment Aggressive treatment of the underlying disease, fluid support, plasma transfusion, and sometimes heparin. Early recognition improves the chance of survival. ## Recovery and Prognosis Guarded to poor. Outcome depends heavily on control of the primary disease. ## Prevention Prompt, aggressive treatment of conditions that predispose to endotoxemia or sepsis. Signs include: bleeding from multiple sites; petechiae; prolonged clotting; often accompanies sepsis or endotoxemia
Jugular thrombophlebitis is a common complication of prolonged catheterization. Digital venous congestion can contribute to hoof problems. Relevant in evaluations of circulatory function and after trauma.
Prolonged jugular catheters increase the risk of thrombosis. Monitor catheter sites for swelling or heat. The frog mechanism is important for normal venous return from the foot.
See the Venous System (Detailed) on our interactive 3D horse model. Open 3D Model