Changes in clinical pathology parameters during gestation in the New Zealand White rabbit

Hematology and serum chemistry parameters were analyzed in 2 groups of preg nant rabbits to assess changes in these parameters over the course of gesta tion. These data were used to generate a historical control reference range for embryofetal development regulatory toxicology studies. During the 28-d ay gestation period, the following major changes were observed. Red blood c ell counts, hemoglobin, and hematocrit increased slightly up to day 13 and subsequently decreased progressively to a nadir for all parameters on day 2 5. Reticulocyte counts increased maximally by day 16 and then decreased to a minimum value on day 28. White blood cell counts progressively declined a fter day 7. Platelet counts increased slightly by day 10, were relatively s table until day 13, then progressively decreased to a nadir on day 25. Aspa rtate aminotransferase and alanine aminotransferease values increased stead ily throughout the study to reach a maximum value on day 25. Triglycerides increased to their maximum value by day 19 and then steadily decreased unti l day 28, whereas cholesterol decreased progressively to reach a nadir on d ay 25. Urea and total protein decreased steadily from day 13 onward. Calciu m values decreased throughout the study to reach a minimum value on day 28. Phosphorus values increased slightly on days 7 and 13 and then progressive ly decreased to reach a nadir on day 28. With a few exceptions, changes tha t occur in clinical pathology parameters during pregnancy in the rabbit are similar to those observed in pregnant women. Therefore, the rabbit can be considered a suitable species for embryofetal development toxicity studies with regard to clinical pathology.