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Platelet disorders in the horse
INTRAVENOUS CATHETERS AND THROMBOPHLEBITIS MEDICAL FORUM The 1 lth Annual Veterinary Medical Forum, put on by the American College of Veterinary Internal Medicine (ACV1M),was held May 20-23,1993, in Washington, D.C.Therewere nearly 300 state-of-the-art, specialist and generalist programs presented by over 200 authorities in veterinary medicine. In addition, a full day of concentrated research abstracts from all facets of veterinary medicine were presented. The largest poster session ever held at the ACVIM meeting was presented. Nearly 2,000 veterinarians were in attendance. Many of the programs were cosponsored by various societies, with lectures on specialized subjects. Of interest to equine practitioners were the following: Comparative Respiratory Society Large Animal, covering "Veterinary support for the foal", "Use of aminophyline in horse and ruminants", and"Rhodococcus Equi; pathogen of foals and humans"; International Society of Perinatology, covering "Assessment of pulmonary function in the critically ill neonate", "Respiratory distress in the foal: Prematurity vs sepsis", and "The use of bovine derived surfactant in foals with respiratory distress"; and American Academy of Veterinary Nutrition & American College of Veterinary Nutrition, covering "The effect of diet on Acid-base status and mineral excretion in horses", "Enteral options for nutritional maintenance of neonatal foals", and "Hyperglycemia in the neonatal foal: Management with continuous insulin infusion."
Drs. Josie and David Dargatz provided information about the cause and treatment of thrombophlebitis. There are many aspects of intravenous catheter use that can lead to vessel inflammation. The longer and larger the catheter used, the greater the chance for complications. The degree of softness is important in avoiding reactions---the softer, the .less chance of complications. The technique of placement of an indwelling catheter is very important. Asepsis is essential. A minimum of movement once the catheter is placed helps to reduce the amount of thrombophlebitis. The catheter should be secured in place with sutures and/or glue. There is no evidence that systemic antibiotics reduce the risk. Stasis of blood flow, injury to the vessel wall and a hypercoagulable state are major contributing factors to the development of thrombophlebitis. If thrombophlebitis develops, the catheter should be removed and the efletted vein should not be used for any purpose. Local treatment of the affected vein with hot packs, hydrotherapy and topical dimethyl sulfoxide (DMSO) or antiphlogistic salves increases blood supply and may reduce local inflammation. Systemic antibiotics are then indicated, if there is sepsis. Surgery may eventually be necessary. Catheters should be replaced every 48 to 72 hours.
PLATELET DISORDERS IN THE HORSE Most platelet disorders in the horse are thrombocytopenias, according to Dr.
Volume 13, Number7, 1993
Debra C. Sellon. Thromboeytosis, or an increase in the number of circulating platelets, occurs occasionally-- usually associated with acute or ehronie inflammatory disorders, and is defined as greater than one million platelets per pl. Thromboeytopenia can be caused by: decreased platelet production; increased platelet destruction; or because of an immune-mediated process. Decreased platelet production can occur in bone marrow disorders. Increased destruction is usually induced by special drugs or toxins, such as snake venom. Most eases ofthromboeytopenia are immune-mediated (IMTP), often without the initiating factor(s) being identified. These eases may be associated with viral orbaeterial infections, neoplasia, or autoimmune disorders such as autoimmune hemolytic anemia, glomerulonephritis, and systemic vasculitis. Horses with IMTP may have petichial and ecohymotie hemorrhages of mucosal membranes, epistaxis, increased bleeding followingvenipuncture, melana, and/or hyphema. Most cases respond to parenteral corticosteroid therapy. It is possible to obtain platelet-rich plasma for treatment. Both equine infectious anemia and equine granulocytic ehrlichiosis (Potomac horse fever) have been associated with thrombocytopenia.
EQUINE PROTOZOAL ENCEPHALOMYELITIS: WESTERN BLOT ANALYSIS Immunoblot analysis of serum and cerebrospinal fluid (CSF) provides antemortem information about exposure to Sarcocystis neurona, the causative agent of equine protozoal myeloencepha-
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Drs. Josie and David Dargatz provided information about the cause and treatment of thrombophlebitis. There are many aspects of intravenous catheter use that can lead to vessel inflammation. The longer and larger the catheter used, the greater the chance for complications. The degree of softness is important in avoiding reactions---the softer, the .less chance of complications. The technique of placement of an indwelling catheter is very important. Asepsis is essential. A minimum of movement once the catheter is placed helps to reduce the amount of thrombophlebitis. The catheter should be secured in place with sutures and/or glue. There is no evidence that systemic antibiotics reduce the risk. Stasis of blood flow, injury to the vessel wall and a hypercoagulable state are major contributing factors to the development of thrombophlebitis. If thrombophlebitis develops, the catheter should be removed and the efletted vein should not be used for any purpose. Local treatment of the affected vein with hot packs, hydrotherapy and topical dimethyl sulfoxide (DMSO) or antiphlogistic salves increases blood supply and may reduce local inflammation. Systemic antibiotics are then indicated, if there is sepsis. Surgery may eventually be necessary. Catheters should be replaced every 48 to 72 hours.
PLATELET DISORDERS IN THE HORSE Most platelet disorders in the horse are thrombocytopenias, according to Dr.
Volume 13, Number7, 1993
Debra C. Sellon. Thromboeytosis, or an increase in the number of circulating platelets, occurs occasionally-- usually associated with acute or ehronie inflammatory disorders, and is defined as greater than one million platelets per pl. Thromboeytopenia can be caused by: decreased platelet production; increased platelet destruction; or because of an immune-mediated process. Decreased platelet production can occur in bone marrow disorders. Increased destruction is usually induced by special drugs or toxins, such as snake venom. Most eases ofthromboeytopenia are immune-mediated (IMTP), often without the initiating factor(s) being identified. These eases may be associated with viral orbaeterial infections, neoplasia, or autoimmune disorders such as autoimmune hemolytic anemia, glomerulonephritis, and systemic vasculitis. Horses with IMTP may have petichial and ecohymotie hemorrhages of mucosal membranes, epistaxis, increased bleeding followingvenipuncture, melana, and/or hyphema. Most cases respond to parenteral corticosteroid therapy. It is possible to obtain platelet-rich plasma for treatment. Both equine infectious anemia and equine granulocytic ehrlichiosis (Potomac horse fever) have been associated with thrombocytopenia.
EQUINE PROTOZOAL ENCEPHALOMYELITIS: WESTERN BLOT ANALYSIS Immunoblot analysis of serum and cerebrospinal fluid (CSF) provides antemortem information about exposure to Sarcocystis neurona, the causative agent of equine protozoal myeloencepha-
379