J R Jaber1, C Carrascosa2, A Arencibia1, J A Corbera2, A S Ramirez2, C Melian2. 1. epartment of Morphology, Faculty of Veterinary Medicine, Universidad de Las Palmas de Gran Canaria, Spain. 2. Department of Pathology and Food Technology, Faculty of Veterinary Medicine, Universidad de Las Palmas de Gran Canaria, Spain.