Studies of bone marrow and leucocyte counts in peripheral blood in fetal and newborn foals.

The research article focuses on studying bone marrow and leucocyte counts in fetal and newborn horses known as foals. The study involves examining the health records of 124 foals and categorizing them into six different groups depending on a variety of factors such as prematurity, bacterial infection, and Equid herpesvirus type 1 (EHV-1) infection.

Study Overview and Procedure

• The study analyzed the medical reports of 124 foals. The foals were categorized into six groups: those that were normal, premature, dysmature (full-term but signs of growth retardation), those suffering from bacterial infection, those suffering neonatal maladjustment syndrome (a disorder where newborn horses act strangely and refuse to nurse), and those infected with the Equid herpesvirus type 1 (EHV-1).
• Furthermore, the research also sampled 6 pony fetuses via catheters in the umbilical vein and artery between 280 and 310 days of gestation.
• Bone marrow aspiration (a procedure to extract and examine bone marrow) was also carried out on 14 additional foals.

Key Findings

• Premature foals displayed significantly fewer neutrophils (types of white blood cells) compared to the healthy ones in the initial 5 hours.
• Similarly, foals with bacterial infections showed significantly fewer neutrophils until they reached the age of 12 hours.
• EHV-1 infected foals had significantly lower neutrophil counts up to age 24 hours and significantly lower lymphocyte counts than all other groups up to age 12 hours.
• Interestingly, premature foals displayed a higher count of neutrophils and a higher neutrophil to lymphocyte (N:L) ratio among the surviving ones compared to those who did not survive for all ages considered.
• The researchers used discriminant analysis which showed a 99% probability that the EHV-1 group could be differentiated from all other groups except for the dysmature foals. The discriminative accuracy between these two groups was about 90%.
• The study observed age-related increases in neutrophil counts and the N:L ratio in catheterized fetuses from 280 to 310 days of gestation.
• The bone marrow aspirates showed no significant changes in the myeloid to erythroid (M:E) ratio during the first 4 days post-partum. The left shift (LS) index was significantly higher in foals suffering bacterial infection compared with normal or dysmature foals.