BASICS
- Petechiae, ecchymoses, and hematomas are forms of interstitial bleeding; the result of impaired hemostasis, vascular abnormalities, or trauma.
- Petechiae occur with thrombocytopenia or vasculitis.
- Ecchymoses and hematomas occur with defects in any aspect of hemostasis (primary, secondary, or fibrinolysis), vascular abnormalities, or trauma.
- A bruise is an ecchymosis/hematoma where hemoglobin is converted to bilirubin and hemosiderin; result is blue/green discoloration.
- The systemic nature of the many underlying causes can result in internal bleeding.
- Clinical signs relate to disorders of the hemic/lymphatic/immune or cardiovascular systems, resulting in overt signs in the skin/exocrine system. Note that coagulation abnormalities and vasculitis are frequently secondary to other primary diseases
- Acquired—no age, sex, or breed predilection.
- Inherited—young purebred horses; autosomal recessive
- Petechiae are tiny, flat, round hemorrhages visible in the skin, mucous membranes, or serosal surfaces.
- Ecchymoses are larger (1–2 cm); a hematoma is a large, localized collection of clotted/partially clotted blood.
- Ecchymoses/larger hemorrhages occur in sites of minor trauma and pressure points.
- With hemostatic deficits, signs of mucosal bleeding (epistaxis, melena, hematuria) and bleeding into body cavities (hemoabdomen, hemothorax) may occur.
- Signs of anemia; acute or chronic hemorrhage.
- Signs of the underlying disease
- Immune-mediated vasculitis (e.g. purpura haemorrhagica).
- Vasculitis caused by infectious agents.
- Septicemia/bacteremia.
- Trauma
- Thrombocytopenia—decreased platelet production; increased platelet destruction and platelet consumption; platelet sequestration.
- Platelet dysfunction—thrombocytopathia
Defects in Secondary Coagulation
- Acquired coagulation defects (e.g. vitamin K deficiency).
- Inherited coagulation defects (e.g. von Willebrand disease, hemophilia A, prekallikrein deficiency).
- Liver disease.
- Neoplasia.
- DIC
Multifactorial (Complex Vascular/Platelet/Coagulation Abnormalities)
- Infections (e.g. equine infectious anemia, equine granulocytic ehrlichiosis, equine monocytic ehrlichiosis, equine viral arteritis, Venezuelan equine encephalitis, African horse sickness, equine herpesvirus, equine influenza, babesiosis, trypanosomiasis).
- Septicemia/endotoxemia/DIC.
- Neoplasia
DIAGNOSIS
TREATMENT
MEDICATIONS
FOLLOW-UP
MISCELLANEOUS