Septic foals had higher hormone concentrations as compared to normal foals, which is an expected endocrine response to critical illness. The increased ACTH/cortisol ratio in nonsurviving septic foals in comparison to surviving septic foals could indicate hypothalamic-pituitary-adrenal axis dysfunction at the level of the adrenal gland in critically ill septic foals.

Summary Forty‐three horses with mitral regurgitation (MR) and congestive heart failure were examined, using M‐mode, 2‐dimensional real‐time and Doppler echocardiography. There was no breed or sex predisposition when compared to the general hospital population. The mean ± s.d. age of affected horses was 7.6 ±8.1 years. Horses with MR and congestive heart failure had significant increases in mean values for left ventricular chamber size, left atrial size and heart rate and significant decreases in interventricular septal and left ventricular free wall thickness. Significant increases in pulmonary artery diameter were detected compared to aortic diameter. Mean values for fractional shortening were not significantly different from normal. All horses had a Grade 3–6/6 holosystolic or pansystolic murmur with its point of maximal intensity in the mitral to aortic valve area. Atrial fibrillation was found at presentation in 24 horses with MR and congestive heart failure. One horse presented with atrial tachycardia and subsequently developed atrial fibrillation. Seven horses had ventricular premature contractions. Exercise intolerance (n = 34), respiratory signs (n = 31), and fever (n = 21) were the most common presenting signs. Thickening of the left atrioventricular valve leaflets, endocarditis, flail valve leaflets, rupture of a chorda tendineae, and mitral valve prolapse were detected echocardiographically. Doppler echocardiography confirmed the presence of a large systolic regurgitant jet in the left atrium in all horses in which it was used, and in many horses, concurrent tricuspid and pulmonary regurgitation was detected. All horses died or were subjected to euthanasia due to the severity of their MR and/or lack of response to therapy. Post mortem examinations were performed in 35 horses and confirmed the echocardiographic findings. The echocardiographic detection of a flail mitral valve leaflet was significantly associated with the detection of a ruptured chorda tendineae at post mortem examination. There was a significant association between echocardiographic detection of a dilated pulmonary artery and its presence at post mortem examination. M‐mode, 2‐dimensional real‐time, and Doppler echocardiography should be used to accurately characterise the valvular abnormalities and assess the severity of mitral regurgitation. Pulmonary artery dilatation, an echocardiographic indication of severe pulmonary hypertension, should be considered a grave prognostic indicator and may indicate impending pulmonary artery rupture.

Although human B19 parvovirus infection has been clearly associated with a number of distinct syndromes (including severe anemia, abortion, and arthritis), detailed knowledge of its pathogenesis has been hindered by the lack of a suitable animal model. We have identified a novel simian parvovirus in cynomolgus monkeys with severe anemia. Sequencing of a 723-bp fragment of cloned viral DNA extracted from serum revealed that the simian parvovirus has 65% homology at the DNA level with the human B19 parvovirus but little homology with other known parvoviruses. Light microscopic examination of bone marrow from infected animals showed intranuclear inclusion bodies, and ultrastructural studies showed viral arrays characteristic of parvoviruses. Another striking feature was the presence of marked dyserythropoiesis in cells of the erythroid lineage, raising the possibility that B19 parvovirus infection may underlie related dyserythropoietic syndromes in human beings. Affected animals had concurrent infection with the immunosuppressive type D simian retrovirus, analogous to HIV patients who develop severe anemia because of infection with B19 parvovirus. The remarkable similarities between the simian and B19 parvoviruses suggest that experimentally infected cynomolgus monkeys may serve as a useful animal model of human B19 infection. (J. Clin. Invest. 1994. 93:1571-1576

There was good agreement between plasma pi meas and piA + G in blood samples obtained from hypoproteinemic horses immediately before infusion of HES. Use of a predictive nomogram did not, however, account for the oncotic effect of HES. Results of comparison of pi meas to piA + G after HES infusion suggest that a significant oncotic effect was maintained for 24 hours in the study horses.

Results suggested that PPH can develop in mares of any age and parity. Treatment was associated with a good prognosis for survival and a reasonable prognosis for future fertility.

Combining the clinician's initial predication of the probability of a foal being discharged alive with that of the model appeared to provide a more precise early estimate of the probability of live discharge for hospitalized foals.

Background: Neonatal foals with isoerythrolysis (NI) often die, but the risk factors for death have not been identified. Objectives: To identify factors associated with outcome in foals with NI and to identify factors associated with death from liver failure or kernicterus in the same population.Animals: Seventy-two foals with NI examined at referral institutions. Methods: Retrospective case series. Information on signalment, clinical examination findings, laboratory testing, treatment, complications, outcome, and necropsy results were obtained.Results: The overall survival rate was 75% (54 of 72). Liver failure (n 5 7), kernicterus (n 5 6), and complications related to bacterial sepsis (n 5 3) were the 3 most common reasons for death or euthanasia. The number of transfusions with blood products was the factor most strongly associated with nonsurvival in a multivariate logistic regression model. The odds of liver failure developing in foals receiving a total volume of blood products ! 4.0 L were 19.5 (95% confidence intervals [CI]: 2.13-178) times higher than that of foals receiving a lower volume (P 5 .009). The odds of kernicterus developing in foals with a total bilirubin ! 27.0 mg/dL were 17.0 (95% CI: 1.77-165) times higher than that of foals with a lower total bilirubin (P 5 .014).Conclusions and Clinical Importance: Development of liver failure, kernicterus, and complications related to bacterial sepsis are the most common causes of death in foals with NI. Foals administered a large volume of blood products are at greater risk for developing liver failure.

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