Mean Platelet Component as an Indicator of Platelet Activation in Foals and Adult Horses

Abstract

Background: Mean platelet component (MPC) is a new platelet variable, measured by modern commercial complete blood count analyzers, that is reduced during platelet activation in humans and small animals.Hypothesis: MPC decreases in horses with clinical conditions that cause platelet activation and disseminated intravascular coagulation (DIC).Animals: We obtained 418 CBCs from 100 sick and 20 healthy neonates and 178 sick and 45 sound adult horses. Sick neonates were classified into septic and nonseptic, and DIC and non-DIC groups. Adults were grouped by diagnoses (systemic inflammatory disorders, gastrointestinal problems, and thrombocytopenia).Methods: MPC together with platelet count, mean platelet volume, platelet distribution width, and platelet component distribution width were measured with a commercial analyzer and compared between the different disease and control groups in neonates and in adults.Results: MPC values were significantly lower in the septic and nonseptic neonates (24.0 6 3.5 g/dL and 26.6 6 2.6 g/dL, respectively) than in the control group (28.1 6 1.7 g/dL). Neonates with DIC had the lowest MPC values (23.8 6 6.3 g/dL). MPC values in adult horses were significantly lower in the inflammatory (23.5 6 4.7 g/dL), gastrointestinal obstruction (23.0 6 5.0 g/dL), enteritis (23.6 6 4.6 g/dL), ischemic (23.9 6 5.1 g/dL), and thrombocytopenia (20.2 6 5.7 g/dL) groups when compared with control horses (26.2 6 3.5 g/dL). Other platelet variables were not different between the control and the disease groups.Conclusion and Clinical Importance: MPC might be a useful variable for quickly and easily detecting platelet activation in sick neonates and adult horses.

Fibrin Deposits and Organ Failure in Newborn Foals with Severe Septicemia

“…In the present study, fibrin deposits were observed in 87.5% of the nonsurviving septic foals when using the IHC technique. This percentage is slightly higher than those reported in some in vivo studies 1,23 that reported a diagnosis of DIC in 50% of septic foals during hospitalization. However, a higher percentage of foals that did not survive were diagnosed with DIC.…”

“…17,37,38 The most relevant finding of the present study is that most nonsurviving septic foals had fibrin deposits in their tissues, specially demonstrated by IHC, and systemic fibrin deposition is consistent with the postmortem diagnosis of DIC. Even considering only the nonsurviving septic foals, this finding is consistent with our clinical impression and the results of other previous in vivo studies 1,24 that nonsurviving septic foals have some hemostatic abnormalities despite the paucity of reported cases in the veterinary literature. In the present study, fibrin deposits were observed in 87.5% of the nonsurviving septic foals when using the IHC technique.…”

“…From the 32 nonsurviving septic foals included in the study, 20 were males and 12 were females. Breed representation was as follows: Andalusian (27), crossbred (3), Arabian (1), and Menorquin (1). Regarding the 20 foals in which blood culture was carried out, 11 had positive results, with E. coli being the main bacteria isolated (n 5 8) followed by Klebsiella pneumoniae (n 5 2) and Pasteurella spp (n 5 1).…”

“…[25][26][27] When blood culture was negative or not performed, the diagnosis of septicemia was confirmed at postmortem examination by the observation of pathologic findings consistent with polyarthritis, omphalophlebitis or omphaloarteritis, enteritis or peritonitis or meningoencephalitis. The septic foals also were classified into 3 subgroups according to the age of the foals at the time of death or euthanasia as previously cited 1,24 : o24 hours, 2-7 and 8-21 days. Foals were kept alive as long as possible and reasonable, considering the foal's suffering.…”

“…A lterations in the coagulation and fibrinolytic systems secondary to sepsis have been documented in several studies in humans, dogs, and horses. [1][2][3] These hemostatic changes are consistent with hypercoagulation, and subsequently a consumption coagulopathy and disseminated intravascular coagulation (DIC). Septicemia has been implicated as the major cause of morbidity and mortality in newborn foals.…”