1. Department of Veterinary Medicine, University of Bari Aldo Moro , Bari , Italy , 70010
2. Department of Veterinary Pathology and Microbiology, University of Nigeria , Nsukka , Nigeria , 410001
3. Boehringer-Ingelheim Animal Health , Lyon , France , 69007
4. Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Messina , Italy , 98122
5. Department of Veterinary Clinical Sciences, City University of Hong Kong , 518057