Haematological profile in foals during the first year of life

Abstract

Foals’ haematological values change constantly during their first year of life. The use of updated age-based reference intervals (RIs) is imperative for providing accurate diagnosis and optimum care for sick foals. The authors' objective was to provide updated RIs for 13 haematological values in 2, 7, 14, 30, 90, 180 and 365-day-old foals and to investigate the changes over time in each measured value. Venous blood was collected at those ages from clinically healthy foals. Thirteen haematological values were analysed. The 95% RIs were reported using a bootstrapping method. Differences over time were examined using Friedman test. RIs for each of the measured values were calculated. Results showed noticeable trends in changes over time in several values. Nevertheless, white blood cell counts significantly increased between day 2 and day 90 (P=0.011) while lymphocyte counts increased from day 2 up to day 180 (P=0.033). The mean corpuscular haemoglobin and mean corpuscular volume (P=0.011) significantly decreased between day 2 and day 90. Normal haematological values in foals not only differ from those in adult horses but also change throughout the first year of life; thus, it is critical that clinicians use age-based RIs when treating sick foals.

Effect of plasma transfusion on serum amyloid A concentration in healthy neonatal foals and foals with failure of transfer of passive immunity

“…Hematologic profiles of neonatal foals have been established with no defined reference range for SAA concentration within the first 72 hours of life, a time of risk for sepsis. [39][40][41] In our study, only 5% (4/86) of the healthy foals <24 hours had a SAA concentration >100 μg/mL, whereas 28% (24/86) of the healthy foals >24 < 48 hours had SAA concentration >100 μg/mL.…”

“…A SAA reference range in neonatal foals has not been established, but clinicians use the degree of increase to describe the magnitude of the change as mild, moderate, or marked, but this categorization is subjective. Hematologic profiles of neonatal foals have been established with no defined reference range for SAA concentration within the first 72 hours of life, a time of risk for sepsis 39‐41 . In our study, only 5% (4/86) of the healthy foals <24 hours had a SAA concentration >100 μg/mL, whereas 28% (24/86) of the healthy foals >24 < 48 hours had SAA concentration >100 μg/mL.…”

Pharmacokinetics of single dose administration of three increasing doses of acetaminophen per os in 1–3‐month‐old foals

“…[34][35][36] BUN was low in some foals likely due to high anabolic rate and nursing. [32][33][34]39 Alkaline phosphatase was increased outside the reference range in 1-3-month-old foals. It is normal for alkaline phosphatase activity to be high in the first several weeks of life but can be increased for up 90 days after birth therefore it is typically not a good indicator of liver function.…”

“…Future studies should be designed to determine if growth and age Another limitation of this study that deserves special attention is that it did not assess the potential for liver toxicity of repeated acetaminophen administration since it was a single-dose study, nor were liver biopsies performed. Acetaminophen-induced liver toxicity is a significant adverse effect in humans 14,33,34 but has not been seen in horses to this date. Importantly, the extent of the liver injury may impair acetaminophen metabolism and prolong the half-life, which can contribute to further liver damage and alter drug disposition.…”

Blood Gas, Acid-Base and Electrolyte Analysis in Healthy Dromedary Camel Calves up to 21 Days of Life

“…It is essential to understand that young and adults are physiologically different, which justifies the need to obtain age-specific reference intervals. Several studies have indicated significant differences between the physiology of young and adult cattle [ 17 , 18 , 19 , 20 , 21 ], and the same can be found for other species such as horses [ 22 ], dogs [ 23 , 24 ] and pigs [ 25 ]. Some studies showed significant differences also in the hematological and biochemical profiles of growing dromedary calves from birth to the 4th week of age [ 26 ], and between young and adult [ 27 , 28 , 29 ].…”