Comparative effects of dexamethasone on placental and foetal organ weights and some linear body measurements in Yankasa sheep and Sahel goats

Dexamethasone is a potent synthetic glucocorticoid use in veterinary and human medicine. However, it causes intra uterine growth restriction (IUGR) and decreases birth weights in some animal species and humans, although each species respond differently. This study investigated the effects of dexamethasone on placental weights and some foetal parameters in Yankasa sheep and Sahel goats with known average gestational length of 148.35 ± 1.50 days and 148.33 ± 1.58 days respectively. Ten adult Sahel goats comprising 8 does and 2 bucks and 10 Yankasa Sheep comprising of 8 ewes and 2 rams were used for this study. Pregnancies were achieved by natural mating after synchronization. Repeated dexamethasone injections were intramuscularly given at 0.25mg/kg body weight on days 1, 3 and 5 during first trimester and days 51, 53 and 55 during second trimester. Foetuses were harvested at day 78 of gestation all through Caesarean section. Foetal weights, crown-rump lengths (CRL), height at withers, heart girth, abdominal circumference, weights of adrenal glands and placental weight were evaluated. Specimens from placentas and adrenal glands were collected for histological analysis. Results showed that the mean placental weights, placental efficiency and foetal body weights were significantly (P<0.05) decreased in dexamethasone treated sheep and goats compared to controls. There was no significant change in foetal adrenal glands and linear body measurements between dexamethasone treatment and control groups in both species except crown-rump lengths (CRL) which was significantly (P<0.05) reduced in Sheep foetuses. It was concluded that dexamethasone caused significant decrease in placental weights and placenta efficiency and hence placental- maternal- foetal transport of nutrient materials in both species and also caused decrease in foetal crown-rump-lengths in sheep but not in goats. This suggests that dexamethasone has some teratogenic effects and that Sheep are more susceptible to dexamethasone treatment compared to goats.Keywords: Dexamethasone, Foetuses, Placenta, Pregnancies, Sahel goats, Yankasa shee

Effects of dexamethasone on leukocytic responses in pregnant Yankasa ewes and Sahel does in Maiduguri, Nigeria

Effects of dexamethasone on leukocytic responses of pregnant Yankasa sheep and Sahel does were investigated. In addition to its anti-inflammatory properties, dexamethasone regulates broad variety of immune cell functions and immune mediator expression at the molecular level and has become subject of considerable interest in clinical immunology. It has been shown to cause leukocytosis involving neutrophilia, suppression of leukocyte blastogenesis and change lymphocyte subpopulation patterns. However, response to medication may differ among species and physiological status. The objective of the study was to compare and evaluate the effects of dexamethasone on leukocytic responses in pregnant Yankasa ewes and Sahel does. Fourteen adult Sahel goats comprising 12 does and 2 bucks and 14 Yankasa ewes comprising of 12 ewes and 2 rams were used for this study. Pregnancies were achieved by natural mating after synchronization. Repeated dexamethasone injection was given at 0.25mg/kg body weight. Blood samples were collected on biweekly basis from each animal through the jugular vein on the same day with minimal excitement prior to feeding. Samples collected were used for the analysis of total white blood cell counts (WBC) and differential leukocyte counts (DLC) (neutrophils, eosinophils, lymphocytes, monocytes and basophils). Dexamethasone significantly (P<0.05) increased total WBC and neutrophil counts in both pregnant Yankasa ewes and Sahel does, but decreased lymphocyte counts in both species. The leukocytic responses of pregnant Yankasa ewes and Sahel does to dexamethasone treatment were similar to reports by other workers in non-pregnant subjects. It was concluded that both species were sensitive to lymphopenic effects of dexamethasone and that pregnancy did not increase the susceptibility of the dam to dexamethasone with regard to leukocytic parameters.Keywords: Dexamethasone, Leukocytosis, Pregnant, Sahel does, Yankasa ewe