Hematology Reference Values for the Iberian Ribbed Newt (Pleurodeles waltl) Under Human Care

Abstract

Simple Summary The Iberian ribbed newt (Pleurodeles waltl) is a European amphibian commonly found in Spanish zoos and rescue centers. Although routine blood tests can help keep these animals healthy, clear, species-specific reference values have been lacking. For this study, we collected small blood samples from 30 healthy adults kept under similar conditions in two institutions. We measured common hematology variables, such as hematocrit and the numbers and types of red and white blood cells, and we used recognized veterinary guidelines to calculate preliminary reference intervals. Following the blood collection procedure, all animals recovered quickly after sampling. Although the ranges are broad, these results provide a practical starting point for interpreting blood tests in this species. They can help veterinarians identify clear abnormalities and support preventive care and conservation programs. Future work involving larger samples, more institutions, and different seasons will make these values even more accurate and useful. Abstract The Iberian ribbed newt (Pleurodeles waltl) is a salamander in the Salamandridae family. Endemic to the Iberian Peninsula and North Africa, it is not commonly found in zoological institutions or wildlife rescue centers. As in other species, routine blood analysis of amphibians under human care is highly recommended, forming an essential component of preventive medicine and effective clinical management. However, despite the great utility of hematological parameters for the diagnosis and prevention of diseases in amphibians, the lack of reliable reference values for many species severely limits their clinical use. The aim of this study is to establish preliminary reference values (RV) for the main hematological parameters in the Iberian ribbed newt. Blood samples were taken from healthy adult individuals (n = 30), females (n = 9) and males (n = 21) maintained under controlled conditions in two zoological institutions. A complete hematological analysis was conducted, which included measurements of hematocrit, total erythrocyte and leukocyte counts, as well as a leukocyte differential. The reference intervals were established according to the guidelines provided by the American Society for Veterinary Clinical Pathology (ASVCP) for sample sizes between 20 and 40 individuals. No significant sex-related differences were detected in the hematological parameters analyzed. Despite the broad reference ranges obtained, these preliminary data provide an essential foundation for the clinical assessment and preventive medical management of P. waltl under human care. Expanding the dataset through collaboration with additional institutions will further refine and improve the accuracy and clinical utility of these reference values.