Age-Related Developmental Clotting Profile and Platelet Aggregation in Foals Over the First Month of Life

Hematology and clinical chemistry in mule foals from birth to two months of age: A preliminary study

In horses and donkeys, age-related changes in hematological and biochemical parameters preclude the use of normal values of adults in the evaluation of foals. This study aimed to obtain data on hematological and biochemical parameters of mule foals from birth up to the second month of life and to assess age-related changes in order to determine if dedicated reference ranges are required in younger animals. Blood samples from seven healthy mule foals were obtained at birth before colostrum consumption, 24 h, 48 h of life, and then weekly until the second month of life. Results were expressed as mean and standard deviation or median, minimum, and maximum values if showing non-gaussian distribution. Kruskal-Walls and Dunn tests were used to verify the differences among sampling times. Significance was set at P < 0.05. Red blood cell count, packed cell volume and hemoglobin decreased from 24 h to one week of age. Mean corpuscular volume and mean corpuscular hemoglobin decreased over the first month. White blood cells increased from birth to seven days of life. Aspartate amino transferase increased while alkaline phosphatase decreased in the first week of life. Urea, creatinine, and lactate decreased, while glucose concentrations increased at 24 h. Ionized calcium and magnesium and total sodium and potassium showed no changes. In mule foals, several laboratory parameters may be the same or intermediate, lower or higher than in equine or donkey foals, but also compared to all other adult species. The preliminary results suggest that for mule foals, age influences hematological and biochemical parameters.

Changes in serum total protein and immunoglobulin G concentrations and Brix percentages in neonatal Arabian foals from birth up to 21 days of age

The aim of this study was to evaluate changes in the serum immunoglobulin G (IgG) and serum total protein (STP) concentrations and serum Brix percentages of neonatal Arabian foals during first 3 weeks of life. Blood samples were collected from 12 apparently healthy foals by jugular venipuncture at birth and at 12-hours, 24-hours, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15 and 21 days of age. Serum IgG and STP concentrations and Brix percentages were measured by the radial immunodiffusion assay, and digital STP and Brix refractometers, respectively. Based on the serum IgG concentrations measured at 24 h, two foals were diagnosed with failure of transfer of passive immunity (FTPI). While IgG concentrations were determined using the data of foals with adequate transfer of passive immunity, other calculations were made using the data of all foals. The mean IgG concentration of the foals increased from birth (<200 mg/dl) to 12 (2068.5 mg/dl) and 24 h (2184.7 mg/dl), and progressively decreased up to 21 days of age (1318.5 mg/dl). The serum IgG concentrations at 12 h were highly correlated with each of the IgG concentrations measured over the 21-day period. The serum IgG and STP concentrations and Brix percentages of the foals diagnosed with FTPI at 12 h did not reach the adequate strata over time. These results suggest that foals can be reliably tested for passive immunity status at 12 h after birth.

Clinical Pathology in the Foal

The dynamic physiologic changes and unique diet during the neonatal period contribute to key differences in clinicopathologic test results of healthy foals relative to healthy adult horses. When reporting results, most diagnostic laboratories only provide reference intervals for mature horses. Thus, failure to recognize the unique differences that occur in foals relative to adult horses can lead to erroneous interpretation of neonatal clinical pathologic values. Thus, the main objective of this article was to review distinct features of common clinicopathologic tests in foals, relative to mature horses.